Trust Me I'm A Doctor (2013) s06e01 Episode Script
Season 6, Episode 1
1 When it comes to our health, it seems everyone has an opinion and everyone has an agenda.
But what's the health advice you can really trust? We're here to weigh up the evidence and use our expertise to guide you Through the contradictions and the confusions.
We do the research no-one else has done.
And put your health at the heart of what we do.
We listen to the questions you want answered.
And ensure you get the information you need.
We're here when you want to know the latest findings.
And not just the latest fads.
I'm Michael Mosley.
In this series, I'm joined by a team of doctors.
Together, we'll cut through the hype, the headlines and the health claims.
This is Trust Me I'm A Doctor.
Hello, and welcome to a new series of Trust Me I'm A Doctor.
This time we're coming from Inverness in the Highlands, where we're carrying out a fascinating experiment to see if consuming probiotics will change your gut bacteria and maybe even improve your health.
We'll also be finding out, can we lose weight while we sleep? And can red wine really help us live longer? We'll just have one more.
One more small one.
I'll discover how to beat the winter blues.
We'll witness a UK first, a UK surgery using 3-D printing.
I can see his heart! And we'll find out if going decaf is dangerous.
But first When it comes to losing weight, there are really two methods.
There's dieting and there's exercise.
I've come across reports that exercise makes us hungrier and more likely to snack on unhealthy treats afterwards, undoing all our good work.
So, we might be better off sticking to dieting.
But is that true? To find out, over the next two days we're running a study with the University of Bath.
We've enlisted sports scientist Dr Javier Gonzales and recruited ten hungry volunteers who are getting ready to diet or exercise.
Yeah, I think exercising will make you hungrier.
I think after a few hours, the hunger will definitely kick in.
I just think dieting always makes me hungry.
Because when you've been exercising, you know, it takes your mind off your hunger.
First, we find out how hungry everyone in the group is on a typical day.
They all do no exercise and eat the same amount of food for breakfast.
Over the next three hours, they all rate how hungry they feel on a questionnaire.
And we're doing some blood tests to get some baseline measurements as a control.
On day two, we split them into two groups.
Diet and exercise.
Before breakfast, the exercise group are burning off 500 calories.
Which is between ten and 18 laps, depending on their body weight.
Great stuff.
Keep pushing.
Meanwhile, our dieters are engaged in much more restful activities.
Great job.
Breakfast time, and it's the dieters' turn to suffer.
They get 500 calories less to eat.
Over the next three hours, we're testing which group gets hungrier.
Again, they rate how hungry they feel.
Just hold that there for me.
And we repeat the blood test.
We're looking at the levels of a hormone called ghrelin.
Why are you focusing on ghrelin? There are many hormones that influence appetite.
Many of these are secreted by our gut.
The interesting thing about ghrelin is it's the only one we know of that stimulates appetite.
All of the other hormones seem to suppress appetite.
And when you have higher ghrelin, what does that mean? So, more ghrelin equals more hunger.
OK.
And what we're going to be looking at is whether exercise, or dieting, affects it more.
When I do exercise, I feel hungrier.
You may perceive that, but we'll find out today.
- If that's true.
OK.
- Yeah.
Once Javier's analysed the data, we gather to find out what he's discovered.
OK.
Results time.
- What did you find? - Let's have a look.
Wahey! So, these are the self-reported ratings of your appetite, compared to your control conditions.
So, on average, the diet group felt hungrier, compared to the exercise group.
Did you all feel hungry afterwards? - Very hungry.
- Super hungry.
Very hungry.
Yeah.
So, there were no exceptions in this group? - No.
- No.
- OK.
I must admit, I was surprised by how big a difference it was between these two groups.
And did people feel less hungry? Yeah, so I felt really, really hungry before the run in the morning.
But then, after the run, I didn't feel particularly hungry and, actually, I wasn't nearly as hungry as I'd been before.
So, on average, the dieters felt hungrier than the exercises.
But what about their levels of hunger hormone ghrelin? First, the exercise group.
On the left is their ghrelin level on the control day.
On the right, the level on the day they burned 500 calories by running.
We've got the exercise group, where you can see there's not much difference in ghrelin concentrations, compared to control.
But for the dieters who consumed 500 calories less, it's a different story.
Poor old dieters getting less calories there and their ghrelin levels going up and it's shouting at you, "Feed me! Feed me!" What's interesting is, it's completely consistent with your questionnaire.
- Yes.
- So, if you do the exercise, it's going to give you lots of benefits, It's not necessarily going to increase your appetite.
- Yeah.
- Anyway, I think you've all been patient long enough.
Please tuck in.
Hooray! So, the good news is that our study adds to a body of research which suggests that doing exercise is not going to make you hungrier.
So, if you combine it with a little bit of calorie restriction, there's a very good chance that you will not only get healthier, but you will also lose weight.
That is a win-win.
Now, it's always a struggle to cut back on the good things in life, not least the booze.
Do we really have to? Over to Dr Chris van Tulleken.
Many of us have the evidence of lived experience that alcohol makes you clever, charming and more attractive to the opposite sex.
Unfortunately, there is the more powerful evidence of robust science which says that even small amounts of alcohol are pretty bad for you.
But there is one drink which claims to be an exception.
Red wine.
We're endlessly bombarded with news reports telling us it might be just a little virtuous.
It's a part of the Mediterranean diet which is meant to make you live longer.
We know that it's not the alcohol that's responsible for the supposed health benefits of red wine.
But could there be something else in here that offsets the harm caused by the alcohol? Red wine is thought to be good for you because it's made using the grape skin, which contains a family of chemicals called polyphenols.
These have been the source of intense study for decades and one has been probed more than most.
Resveratrol.
Now, we've known about this chemical for a long time, but it wasn't until the 1990s that it was discovered in red wine.
So, why has it got scientists so excited? This is an East African killifish.
Let's call him Arthur.
Arthur is a handsome beast, but sadly, his time on this Earth is short.
Just a few months.
But that's useful for scientists who study longevity.
So, the scientists ran an experiment to see if giving resveratrol to fish like Arthur made them live longer.
What they found was that the fish in the experiment given the resveratrol lived up to 40% longer.
Now, that's pretty astonishing if you're an African killifish.
What you'll find if you read beyond those headlines that say something like, "A glass of red wine a day keeps the doctor away," is that at the bottom of the article, it will say that the experiments were actually done on a fish like Arthur, a worm, a fruit fly, or sometimes just cells in a dish.
So, although the research may be promising, it doesn't amount to evidence that red wine may have health benefits that means you and I will live any longer.
And even if we do one day discover that resveratrol has a significant beneficial effect on people, there's still a catch when it comes to getting it from wine.
This is a glass of Pinot noir, it happens to be from the Yarra Valley in Australia.
Now, Pinot noir is a light red with low acidity, medium tannins and some of the highest levels of resveratrol of any wine in the world, at about 10mg per litre.
Unfortunately, though, most of the studies on resveratrol have been done using capsules, like this.
And in order to get as much resveratrol out of my wine as there is in this capsule, I would need to drink all of these bottles here.
So, I'd better get going.
So, despite many years of research, we're still not entirely sure what lies behind red wine's healthy reputation.
And it may well be that we've been looking at it the wrong way.
When drunk in moderation as part of the Mediterranean diet, red wine accompanies nutrient-rich foods, like fruits, vegetables, fish and nuts.
And the evidence suggests that it's the diet taken as a whole that leads to a longer, healthier life.
Now, having one small glass of red wine with food is not going to do you any harm, but you have to ask yourself honestly, when was the last time you did that? If you're anything like me, you have one glass over dinner and then probably another glass over dinner, then you finish off the bottle in front of the television with dessert.
So, sadly, red wine is not some kind of delicious medicine where the more you drink, the better it is for you.
I will just have one more.
One more small one.
SNEEZE Every year in the UK, we spend over ç¿700 million on probiotic products that promise to improve our health by enhancing the mix of bacteria in our gut.
More and more research is showing how our gut bacteria influence every aspect of our health.
And yet, there is still so much that we don't know about this inner ecosystem.
If you believe the hype, our gut bacteria can help tackle a dizzying array of disorders.
From poor digestion and bowel diseases to allergies, acne, obesity, and even mental health problems.
Popular probiotic products say they can alter our gut bacteria for the better.
But do they actually work? Probiotics are essentially supposed to work in the opposite way to antibiotics.
Instead of killing harmful bacteria, it it's claim they add new, beneficial bacteria to the complex swamp of microbes that already live in our intestine.
However, there's a catch.
Before the bacteria in probiotic products can change our gut for the better, they have to survive the perilous journey through the acid bath that is our stomach and set up home in the intestines.
How well they can really do this is a hot topic right now and is exactly the kind of thing that Trust Me likes to test.
So, with the help of NHS Highlands, we've enrolled 30 residents of Inverness who are going to volunteer their guts in the name of science.
We split our volunteers into three groups.
They'll be helping us test a market leading probiotic against some alternatives.
All closely scrutinised by Dr Adele Costabile of Roehampton University.
Our first group will be taking a daily dose of a top-selling probiotic yoghurt, available in most supermarkets.
Products like these are specially formulated to contain particular bacteria strains thought to be beneficial.
This yoghurt contains just one specific bacteria.
One specific bug that can help your gut to make a little bit healthier.
However, some researchers claim these drinks don't work.
They think our stomach acid, which kills off harmful bacteria, is also killing the good bacteria in these products.
So, will our volunteers see any difference? Our next group are trying a different type of probiotic.
A fermented milk drink called kefir.
It's long been a traditional part of the diet in Central Asia, but it's recently started to appear in our supermarkets.
This stuff naturally contains dozens of strains of live bacteria, way more than the familiar yoghurt drinks.
Kefir has been in our diet for several hundred years.
It doesn't contain only one species, but contains more bacteria, plus some yeast.
But does having more bacteria make it more likely that some will survive our stomach acid? In four weeks' time, we should see if these bacteria have managed to make a new home for themselves within your gut.
But to avoid the problem of stomach acid altogether, our final group will try a different way to boost their gut bacteria.
Instead of taking a probiotic, they'll be given what's called prebiotic diet - foods that contain a type of fibre that the good bacteria already in our gut thrive on.
It's a fibre that can target the good guys that are already down there in your digestive system.
The prebiotic fibre we're going to test is one that's readily available in common veg.
It's called inulin and it's found in leeks, onions, garlic, asparagus and Jerusalem artichokes.
I got the inulin.
Soup is the way to go, maybe some stir-fries.
I don't know.
I think variety's the thing, isn't it? I got kefir, which I've never heard of before.
So, I'm interested to see what it tastes like.
I got the yoghurt drink.
The advert says that they did you good, so I tried them.
I didn't notice any difference.
So, that's why I'm doing this trial, because I want to know, do they work or not? Before our volunteers start the experiment, we're taking urine and stool samples which will allow us to test the volume and variety of their existing bacteria.
In four weeks' time, we will test our volunteers again to see if there've been any changes to their guts.
Many of us would like to be able to cut back on our calories, but we find it hard to do.
GP Dr Zoe Williams has been investigating a surprising way to do this without even noticing.
When it comes to keeping our weight in check, we naturally turn to diet and exercise, but intriguing research suggests that there may be an easier way.
Surprisingly, getting enough sleep could make all the difference.
On a cold, dark night, we've invited four volunteers into the Kent countryside.
We're going to test a recent research claim that suggests the amount they sleep will affect how much they eat.
So, we're giving them something that will keep them up all night.
Oh, my God! The hairs! Oh, it's holding my finger, look.
These pretend babies are designed to cry a lot.
I can't do it! We've told our volunteers that we're looking into sleep, so they have no idea that we're really going to measure how their lack of sleep affects their food intake.
I'm going to be watching their progress with sleep expert Dr Denise Robertson from the University of Surrey.
Sleep interacts with every other aspect of your life.
So, sleep is going to affect your ability to make good food choices, your ability to, sort of, resist snacks.
It's bedtime for our volunteers.
But not for long.
BABY CRYING A bad night's sleep disrupts two key hormones that play a role in hunger.
One, we heard about earlier in programme, ghrelin.
You see an increase in ghrelin.
And ghrelin is a hormone that's been linked to food intake.
It drives your hunger.
The other has the opposite effect, signalling when we're full.
It's called leptin.
At the same time, you'd see a suppression of leptin and leptin is a satiety signal.
- OK.
- So the combination of hunger going up, satiety going down, you'd expect them to feel physically more hungry.
The morning after the night before.
This is the thirstiest baby in the world.
I've had, maybe, three or four hours' sleep.
For breakfast, we laid on a spread of healthy and not-so-healthy foods.
Look, the granola's going down well.
- Yeah.
- And the pastries are very popular.
What you would expect is things like pain au chocolat, for example, because it's high-fat, it's high sugar, you could almost expect to see them going back for seconds or thirds if they were sleep deprived.
Rather than hitting the bananas and the apples.
As a comparison, we also gave our volunteers a night of normal, undisturbed sleep and, again, in the morning, counted the calories.
Knowing the calorie content of each food, Denise is using our footage to tot up each person's total.
And it's time for the results.
Hi, guys.
It's good news.
You're all very good parents, except for one person.
- Ronan.
- We knew it! But we're not really interested in that, because that's not really what we were looking at, at all.
They were actually monitoring how much you ate.
Because we're interested to know if the amount of sleep you get affects how much food you put on your plate.
- Mm.
- OK.
- And what we found is Ellie and Bertie, you had quite a quite a difference in your sleep.
You were losing three and a half or four hours.
You did respond to the sleep loss, actually, you ate considerably more.
You just let yourself go for it.
Overall, Ellie ate 57 calories more at breakfast when she was tired.
While Bertie ate 108 calories more.
Eating 100 extra calories every day is enough to make you put on 5kg in weight over a year.
Ronan barely slept a wink and whilst he didn't eat more, he did choose more sugary foods.
But the person who got the most sleep responded rather differently.
Howie, you managed to sleep quite well.
- Yeah.
- Even with the baby.
- I was.
- You just ignored her.
No, I didn't ignore her.
Interestingly, after his good night's sleep, Howie's eating habits were unaffected.
These experiences are consistent with an analysis by King's College London that reviewed dozens of smaller studies involving sleep and appetite.
It showed that although not everyone is affected in the same way, on average, getting less than seven hours of sleep night led to people eating significantly more overall.
These guys are going to go back home where they don't have babies.
What can they do to make sure that they have a good night's sleep? You would have blackout blinds.
You would make sure the room wasn't too hot.
You'd want to take out the laptop, the tablet, the mobile phone.
I guess one way of thinking about it is that the bedroom is for two things and two things only.
One of those is sleep and You can probably work out the other one.
Although Ronan looks confused.
So, if you're struggling with your weight, then it's well worth considering not just your diet and exercise, though they're important, but also think about how much sleep you're getting.
Aim for at least seven hours per night and not only will you feel better, but you'll be more able to resist those sugary treats.
For information on how to get a better night's sleep, visit Lots of you have been sending in your health questions.
And we've been getting you answers.
What is gout and what can I do to avoid it? Gout is actually a form of arthritis causing pain in the joints, and it's on the increase, thought to be due to an ageing population and rising obesity.
It currently affects around a million people in the UK.
Gout can affect any joint, but typically it starts here, in the big toe.
Now, what causes it is the build-up of a substance called uric acid.
And if your kidneys don't clear it, then you get deposition of crystals in the joints.
And that's what causes all the pain and inflammation.
But research has shown that there are things you can do to help avoid developing it.
Now, gout is associated with being overweight, which is perhaps why it's becoming more common.
The particularly bad form of fat is the visceral fat you get around your gut, which seems to block the clearance of uric acid.
The good news is, if you lose weight then you'll see a rapid improvement in your gout.
But there are also specific foods and drinks to avoid if you're prone to gout.
Any drinks with lots of sugar, even fruit juices, are out.
Instead, you should drink plenty of good old-fashioned water.
Alcohol can raise uric acid levels too.
And some foods contain a high level of proteins called purines, which our body breaks down into uric acid.
Red meats and poultry are OK in moderation, but it's best to avoid seafood and gamey meat.
On the other hand, skimmed milk, water and low-fat yoghurt actually seem to help.
Along with plenty of fruit and veg, of course.
If you do develop gout in a joint, rest and ice can help.
Anti-inflammatories, like ibuprofen or naproxen, can reduce inflammation and pain.
Aspirin's OK in low doses, but if you're taking more than 75mg a day, it can actually increase your uric acid levels.
Your GP can give more advice and treatment options.
Your doctor may decide to inject your joint with steroids or perhaps give you medication to balance out the uric acid levels.
Either way, hopefully it'll get you back on your feet and pain-free.
Now and again, a new bit of technology emerges in a completely unrelated field, like engineering or design, which has the potential to transform an area of medicine.
Surgeon Gabriel Weston has been following one such story and has witnessed an operation, the first of its kind in the UK.
Edward Evans had always been a keen sportsman and coach.
But one day, seven years ago, when he was 54, he began to experience a pain that would change his life.
I come down on most Sundays to watch my sons play rugby, and on this particular Sunday, I started to feel a dull ache in the centre of the chest.
What Edward was feeling was a rare infection that had taken hold in his sternum - the bone at the centre of his ribcage.
This made him extremely unwell.
Doctors had no option to remove his sternum.
Replacing it with an implant wasn't an option at the time because any foreign body inserted when Edward was already so ill carried a high risk of further infection.
All the surgeons could do was cover the gap with some of Edward's own muscle, leaving his heart and lungs so vulnerable that a blow to his chest could be fatal.
I was playing five-a-side up until that point, teaching the boys to play rugby on and off.
So, that Stopped doing that.
And I miss it.
I like to keep active.
I want to keep fit.
I want to cycle, I want to walk.
In my mind, there's a massive correlation between keeping fit and feeling strong and feeling old.
Edward could continue to live without a sternum, but his vulnerability is limiting his quality of life.
Over time, his body has recovered from the infection, which means that surgery would be less risky.
And he's been offered a new kind of implant that's never been tried in the UK.
Normally, the only option for people like this would be an implant made out of mesh and cement.
But what Edward's about to receive is completely different.
It's a titanium sternum made especially for him and 3-D printed on the other side of the world.
CT scans of Edward's chest have been sent to Anatomics in Melbourne, Australia.
World leaders in the design and production of bespoke surgical implants.
Their designs are loaded into the 3-D printer which has a chamber filled with powdered titanium and an electron beam which fuses the particles together, layer by layer.
And now, it has printed Edward's new sternum.
The loose powder is blown away, revealing the implant for the first time.
The titanium is light, strong and rigid, and less susceptible to infection than cement.
The finished sternum will be implanted at the Heartlands Hospital in Birmingham, by thoracic surgeon Mr Ehab Bishay.
They, in fact, have reconstructed the defect to match completely what we took out.
It will protect the underlying structures.
The thing that we cannot tell you is whether it will improve your lung function, the mechanics of your breathing.
- OK.
- You're a pioneer.
And hopefully, you'll show the advantages of something like that.
The procedure begins with the plastic surgeon, Mr Khalil, taking down the muscle flap that was used to cover the defect several years ago.
The structures that these gentlemen are operating up against are the very structures which keep us all alive.
What Mr Khalil has already found is that the muscle has become very thin, so he's coming to the lung much more quickly than he'd anticipated.
Once Mr Khalil is finished, Mr Bishay will perform the delicate task of fitting the new sternum into place.
Normally, we would have to mould the cement ourselves, by hand, handling it.
So, the risk of infection is increased.
Here, you've got some that's ready-made, should slot in.
You might not see that today, because, obviously, this is our first time using this technique, but I have faith in the fact that it's been reconstructed so precisely.
In order for Mr Bishay to get the outside of the implant going over each rib head, he's had to ask his anaesthetic colleague to deflate the lung on purpose.
Now, the implant will be tried in situ for the first time.
There's an enormous amount of surgical skill and adjustment that comes into play, trying to make it perfectly fit, where it will hopefully stay for the rest of Edward's life.
OK.
At last, the perfect fit is achieved.
It's an amazing thing to see and it's now just for Mr Bishay to fix it there with screws.
Although the operation has gone smoothly, it remains to be seen how well the implant will function for Edward.
Several weeks later, Edward has recovered from the procedure and it's time to find out.
Throughout this process, Dr Nicola Oswald has been using motion capture and cameras to monitor Edward's breathing and movement.
Past 100.
Well done, keep going.
So, has the implant made any difference? This was before surgery.
And you can see when he takes a breath in, that the ribcage moves in rather than moving out, like you expect, - taking a deep breath.
- How does that compare with the one after surgery? The overall shape of the chest looks more normal.
Then when he takes a deep breath in there, the ribcage moves out in time with him breathing in and then back in, in time with him breathing out.
So, it's gone back into synchrony again.
These results are extremely encouraging and could pave the way towards even larger and more complicated implants.
So, what's the main difference for you, Edward, now compared to before? I feel confident now.
It feels like, probably, how I felt when my chest was was normal.
Whatever I do, simple or difficult, you know, I feel better doing it.
I can fall over with confidence, basically.
That's the truth! Coming up - how to spot an asthma attack and save a life.
And can decaffeinated coffee actually be bad for you? But first Four weeks ago, we started an experiment in Inverness to see if probiotic products are really the best way to improve the mix of healthy bacteria in your gut.
30 volunteers have been trying one of the three options.
Our first group have been taking a market-leading probiotic yoghurt drink.
These drinks are formulated to contain one or two specific types of bacteria that manufacturers know to be beneficial.
I was taking probiotic yoghurt.
And how was that for you? Personally, I thought my health improved.
Our second group have been taking a traditional drink called kefir, made by fermenting milk, which makes it naturally full of different types of live bacteria.
It was quite an acquired taste to begin with, because it's very sour.
But I got used to that.
And our third group have been on what's called a prebiotic diet, rich in the type of fibre called inulin, thought to boost the good bacteria already in our gut.
It was fine.
It was a bit of a challenge on some days.
I love leeks, I love artichokes, I love asparagus, but there's only so much you can eat in a day.
Dr Adele Costabile now has the delightful job of analysing our volunteers' stool samples.
This will reveal whether any of our methods have improved the mix of bacteria in our volunteers' guts.
First, the probiotic yoghurt.
This group saw a promising change in the levels of bacteria that had been linked to obesity.
This is consistent with other, bigger studies that suggest a range of benefits, particularly in treating specific gut conditions.
Next, the group who were on the diet rich in the fibre inulin.
In our trial, this group saw a rise in one bacteria type known to be good for maintaining gut health.
And this again is consistent with other studies that have shown inulin to be beneficial.
But our most significant result was in the group taking the fermented milk drink, kefir.
We saw for this group differences between before and after the four weeks' treatment.
We saw a beneficial effect.
Basically, the good guys down there in your gut, they were different compared with the beginning.
This is something promising.
Our kefir group saw a rise in a whole family of bacteria called lactobacillus.
These bacteria are thought to be good for general gut health and they're known to help certain conditions, including traveller's diarrhoea and lactose intolerance.
So, in our trial, amazingly, it was the fermented drink, kefir, that most of our volunteers had never even heard of before, that actually caused the most changes to their gut bacteria.
I would actively be interested in trying the kefir drink, just to see the results of that.
Andy, were you surprised by the results of the kefir? The fact that it was this fermented drink with maybe quite a variety of bacteria made me think it would have an affect.
Now, the kefir was such a clear winner in our test that we want to find out more.
What makes it so full of healthy bacteria, and are there other foods like it we should all be eating? This smells really nice.
More on that later in the programme.
The winter months can play havoc with our health.
Colds, flu, joint pain and even heart attacks are more common.
But is it also messing with our minds, giving us the winter blues? SAD, seasonal affective disorder, is also known as winter depression, but tends to come on during the winter months.
Now, common symptoms include tiredness, low mood, a craving for carbs and weight gain.
In some cases, it leads to severe depression.
SAD was first recognised in the early 1980s.
Since then, it has become an accepted medical condition and it makes the headlines most winters.
A recent survey found a third of us think we might suffer from it.
So, how do you know if you've got it? How do you treat it? Should I worry about SAD? Personally, I've not thought much about SAD, since I'm pretty sure it's something I've never experienced.
But I'm putting that assumption to the test.
I'm having my SAD potential assessed by Dr Brenda McMullen, a neurobiologist and psychiatrist from Copenhagen University Hospital.
I start with a questionnaire, the basis of most mental health assessments.
This asks about my mood and behaviour through the year.
For a full diagnosis, it would usually be followed by an interview with a psychiatrist.
So, what do my answers reveal? You mention in this that you have changes in all of the items that we look for in a person who suffers from seasonal affective disorder.
So you say here you've experienced changes in the length of your sleep, in your appetite, in your weight, in your social activity and in your energy levels.
It seems like you are feeling the best in August and July and you are feeling worse, gaining most weight, sleeping most in December.
Yes.
I was surprised when I started to fill it in, I started to realise I probably I do have shades of seasonal affective disorder, which is something I hadn't really thought about before.
Where would I fall in terms of the average, do you think? You are worse off than average.
It's 11.
A maximum of 24.
So, you're in the middle range, but on average is probably closer to six or seven.
How common is it? Seasonal affective disorder is not something that you either definitely have or do not have.
It is a spectrum.
So, many people would have some degree of seasonality, but not being depressed at all.
And you would have probably 5% having a depression and maybe 5% having no symptoms at all.
So, like a lot of people, I have some SAD symptoms.
But I'm not amongst the small percentage who've been diagnosed with severe seasonal affective disorder.
Those patients have been the subject of Brenda's research.
Using brain scans, she noticed a difference in brain activity suggesting they were being deprived of serotonin, a chemical that is thought to regulate mood and appetite.
Although we're not sure why this happens, it seems the seasons can affect us much more powerfully than I had realised.
Now, that was a big surprise.
I've known for a long time that I do not like dark, wet, wintry days, but I never imagined that I might have SAD.
It certainly means I am intensely curious to find out more.
To understand the condition better, I'm meeting Professor Anna Wirz-Justice from the University of Basel, Switzerland, who has been researching this condition for decades.
So, what are the main theories about the causes of SAD? There are two aspects that are important.
If we go back to basic biology of seasonality, it is the day length that triggers certain changes in physiology and behaviour.
Hibernation in winter, adding weight, eating a lot more, sleeping longer.
And the other one is that we don't get enough light to set the biological clock to synchronise our rhythms to 24 hours and, therefore, they drift later and later.
And if you have a late clock, you are more vulnerable to depression.
In what ways is light resetting the clock? The last 15 years has been a revolution in that a new kind of photoreceptor was found in the eye which is sensitive to light.
These photoreceptors transmit directly to the biological clock in the brain - information that it's dawn or dusk, that it's light or dark.
By having light in the morning, you are regularising all your rhythms in your body, they are all getting synchronised.
Right, so it goes straight in there, just sort of And goes, click! And says your biological clock is now awake and functioning.
So, what sort of treatments are available for SAD? Light is the treatment of choice, of course.
With or without antidepressants.
And the third, the different psychological treatments.
One of my main messages for anyone who suffers from the winter blues or from winter depression, is the easiest treatment would be a regular walk outside.
Most of the studies show that light in the morning is better.
So, if I just sit around my house, I'm not going to get it just from, sort of, overhead lighting - or things like that? - No, you are not.
- You need special lamps.
- You go outside.
OK.
It's cheaper.
Is there any value in buying a light box? A light box is the most reliable method of treatment.
You have it in your house and you sit in front of it for half an hour every day.
So, have you seen a lot of lives transformed by light? A great many people.
They finally have a diagnosis and they have a treatment that is fairly straightforward and it works rather quickly, within one or two weeks.
And I think one of the important things for light therapy, you are treating yourself before you sink really into this winter depression.
Speaking to our experts has been a real eye-opener.
I was surprised to discover there was a spectrum of winter depression on which we might all find ourselves.
So, should I worry about SAD? Well, it turns out I should.
And should you worry about it? Well, that depends on whether you regularly get the winter blues or not.
If you do, then the answer is simple.
Light.
Go out for a morning stroll, and it's important it is done in the morning, or invest in a light box.
For more information, go to the Trust Me website where you can also try a questionnaire to see if you have any symptoms of seasonal affective disorder.
If you do have health questions you've always wanted answered, then do send them to us via our website.
I've heard that decaf coffee is full of the chemical used in the removal process, so it's best avoided.
Is this true? These days, people are turning away from traditional coffee to decaffeinated options instead.
Even in the case of posh coffees, like this one.
And that's because some of them think that it is a healthier option.
But is it? The first thing to look into is how decaf coffee is made.
There have been reports in the media claiming that some of the methods used to remove the caffeine involved substances that are actually bad for us.
All decaffeination methods start with this.
The green, or unroasted coffee bean.
Most methods use water to get the caffeine out of the bean.
Then a chemical solvent is often used to get the caffeine out of the water.
The solvent is then removed and the remaining water is dried off.
There are two possible chemical solvents that can be used in this process - both of them, technically speaking, toxic.
But by the time the process is complete, they're found at such vanishingly low levels that they are below the European regulated safe limit.
But to avoid any solvents, there are other methods that some manufacturers use to remove the caffeine.
One alternative uses a charcoal filter.
Another uses carbon dioxide at extremely high pressures.
So, you can choose solvent-free coffee if you want.
But there's not any evidence that it's actually healthier.
Now, coffee aficionados will tell you at great length, of course, that the method used to decaffeinate coffee can affect the taste.
So if you really worry about these things, then I would be guided by your taste buds and don't sweat about the methods used to produce the coffee.
There is, however, something else that you should be aware of if you're thinking of going decaf.
Your decaf may not contain any chemical nasties, but you might be surprised to know that it probably does contain some caffeine.
A 2006 study conducted in Florida found that nine out of the ten decafs they tested had at least some caffeine in them.
So, the two-shot decaf latte that you're drinking might contain as much caffeine as a can of Coke.
For most of us, though, if you're worried about what your daily cuppa's doing to your health, there's something other than caffeine you might want to think about.
A cup of black coffee is virtually calorie free.
Add milk and sugar, it goes up to about 50 calories.
But by the time you're looking at one of these, a giant mocha latte, it can be up to 500 calories.
The same as a big burger or a large piece of cake.
So, caffeinated or not, you can enjoy a small cup with an easy conscience.
But treat this as a treat.
Asthma is one of those things we associate with childhood, yet one in 12 adults are also affected.
We think of it as mild, and yet it can be life-threatening.
Which is why it is so important to be able to recognise the signs and the symptoms.
Over to Dr Saleyha Ahsan.
There are over 5.
5 million people with asthma in the UK and every year around 1,000 of them will lose their lives to an asthma attack.
But if more people knew the warning signs, some of these deaths could be prevented.
My brother has had asthma all his life.
My father got it as an adult and has needed intensive care.
His brother, my uncle, died of it.
That's why I'm so keen to talk about the signs and symptoms of asthma, so that people can spot a dangerous attack quickly and save lives.
Asthma is a condition that affects the airways, the tubes that carry air in and out of the lungs.
If these become irritated, that can lead to inflammation of the airways, the muscles tighten and the tubes narrow.
And this causes shortness of breath, wheezing, and it can even lead to a life-threatening asthma attack, needing hospitalisation.
We still don't know what causes asthma in the first place, but for those who have it, there are many things that can trigger an episode.
And even emotions and stress.
Another surprisingly common trigger is exercise.
But despite that, doctors actually recommend it for asthma, especially swimming, as it can calm and regulate breathing.
So, I've come to an outdoor swimming club in Kent.
I dipped my toe in and the water's freezing.
A few of the members here have asthma.
Describing their experiences help others recognise the symptoms.
It feels like a tightening in your chest.
It doesn't matter how many times you breathe in, or how deeply you breathe in.
It stops you sleeping, I cough a lot in the night.
My breath shortens and I think I'm not getting the air out of my lungs and, therefore, I find it hard to get the air back in again.
To show the non-sufferers in the group what asthma actually feels like, we've set up a demonstration with the help of Dr John Dickinson and a device that impedes your breathing in a way that mimics asthma.
When the non-asthmatics put this in their mouth, they'll find it pretty easy to breathe in - Yeah.
- But they'll find it pretty hard to breathe out and that's what happens in asthma.
Just think how long it takes to empty your lungs, think about that asthma response.
You can see how easy it is to get panicky when you're feeling like that, to start hyperventilating.
That's horrible.
That is actually horrible, because you can't get breath out - and you're already wanting to breathe back in.
- Exactly.
Feel how much longer it takes to breathe out.
- What did you think? - It's hideous.
- Yeah.
- It's horrible.
That's using all your muscles.
That's huge exercise.
You all right? - Horrible.
- Yeah.
- Yeah.
I'm having a lot of sympathy and empathy for you guys right now.
I really am.
'Anyone who has asthma should always carry an inhaler, 'a spray containing a muscle relaxant to open up the airways 'and ease breathing.
'If you see someone struggling with asthma, 'you can assist by keeping them calm because this can help bring 'their breathing under control.
'But sometimes, if the symptoms continue, 'things can become much more serious.
' Every ten seconds, someone is having a life-threatening asthma attack.
So, what are the warning signs? The person is extremely breathless, perhaps struggling to speak.
Their symptoms are getting worse.
Their asthma inhaler isn't helping.
Children may complain of a tummy ache.
If an asthma attack continues untreated, the lack of oxygen can be fatal, but there are things you can do to help.
So, if someone is having an asthma attack, follow these instructions.
Keep them and yourself calm.
Sit them upright.
Make sure that you've located their inhaler.
Get them to take one puff of their inhaler every 30 to 60 seconds.
It can feel like a long time in between, but it's the right thing.
Repeat up to a maximum of ten puffs.
Take another puff of that, please.
Excellent, well done.
If they didn't have their inhaler with them on the day, - what would you do then? - Call 999 straightaway.
You should also call an ambulance if they don't feel better after ten puffs, or if they're a child.
If, in an extreme situation, the patient stops breathing and their heart stops, you must start CPR immediately and don't stop until the ambulance arrives.
Nice and easy.
Nice and calm.
If you have asthma, learn to recognise your triggers and always carry your inhaler.
Make a plan with your GP of what to do if you have an asthma attack.
And for the rest of us, we should learn to recognise the warning signs of an asthma attack, particularly for children.
Wheezing, shortness of breath, they are unable to finish a sentence without having to breathe, and sometimes children complain of a tummy ache.
For a list of symptoms and more, check out Earlier in the programme, we did a big experiment to test three different ways to boost the good bacteria in our gut.
The surprise winner was a little-known drink called kefir, made by fermenting milk.
Having discovered in our trial that fermented foods worked best, we wanted to look at the subject in greater depth.
What exactly is going on when food is fermented, and should we all be eating more of these foods? To find out, I first need to take a closer look.
Fermentation is the process by which bacteria and yeast turn carbohydrate into things like gases, acids and alcohol.
Now, we are familiar with the idea you need micro-organisms to produce your beer and wine, but until fridges were invented, it was actually one of the main ways to preserve foods.
Fermented foods include pickled vegetables, cheese, chutneys, sourdough bread, soy sauce and drinks like kefir.
And it turns out, they're surprisingly good for us because the way they're made encourages the growth of helpful bacteria.
Anna, Simon and Gabba all regularly make fermented foods and drinks using traditional methods.
Today, Anna is making some soft cheese and Kombucha, a fermented tea-based drink.
I'm using the culture to make it.
Simon is making sauerkraut - preserved white cabbage - and kefir, the milk-based drink that did so well in our trial.
You just get these grains.
Put them in with milk.
And Gabba is making kimchi, a traditional Korean dish of fermented vegetables.
When you try it, it's just fire! There are different methods, but a common one is to chop up vegetables and leave them in a salty liquid.
Over time, the salt kills off the bad bacteria, allowing good bugs like lactobacillus to thrive.
These bacteria produce lactic acid which preserves the vegetables and gives the food its distinctive flavour and aroma.
Polish Korean kimchi.
Here we go.
Here.
- Spicy.
- It's spicy.
Whaa Ooh! But if you don't have time to ferment at home, these foods are increasingly available in supermarkets.
I want to see how the amount of healthy bacteria in them compares.
What we're going to do is we going to take these home-made fermented foods and we're also going to get the shop-bought equivalent.
We're going to send them all off to a laboratory to be analysed.
Now, I know which I prefer, from the point of view of smell, taste and texture, but it will be extremely interesting to see how the bacterial content of these foods compare to those which you can buy in the shops.
Scientists at the University of Roehampton have placed samples from each product on petri dishes and are painstakingly counting any helpful bacteria that grow.
To discuss the result, we brought in the leading expert in fermented food and gut bacteria, Dr Paul Cotter from the Teagasc Food Research Centre in Cork.
So, what are the results showing? So, in the kimchi, the sauerkraut, cheese, kefir and Kombucha, from the home-made products in the blue, you're seeing quite high levels of bacteria, particularly lactobacillus bacteria.
And in a commercially sourced products, you're only seeing those lactobacillus present in the kefir and Kombucha.
These commercial providers presumably used a more traditional fermented food processing or preparation.
Some commercially-produced foods will be pasteurised in order to make sure they're safe and to give them a long shelf life, But during that process, you're also killing the good bacteria along the way.
Is there much evidence that lactobacillus, if you take it in the form of a preserved food, is actually good for your health? It depends on which lactobacillus are present.
There are many different species and even within a particular species, there are different strains, some of which have good properties and others which don't.
And I suppose that's why, in the case of probiotics, people will have studied an individual strain and know a lot about it.
But by eating a fermented food with lots of different varieties, at least there's a chance that some of them in there will be good for you.
So, for general good gut health and to acquire a range of helpful bacteria, fermented foods are an excellent way forward.
And our tests suggest that you'll find more of these helpful bacteria in traditionally-made fermented foods.
But if you want to make your own, then do follow a recipe and make sure your hands, jars and raw ingredients are clean.
I think the key thing if you are making it at home is it's safe and you're not encouraging the growth of disease-causing or spoilage microbes.
So, you need to have good-quality raw material, you need to have a recipe, correct ingredients, follow the recipe so that you're not storing it too long or at the wrong temperature.
And I think in those circumstances, you can't go too far wrong.
The biome, the gut bacteria, is clearly a really hot area of research and there is obviously still an awful lot that we need to learn.
That said, I am convinced that fermented foods are good for the gut.
In fact, I am going to go home now and make my own kefir.
That's it from Inverness.
Next time, we're in Walsall, where we're doing a really fascinating experiment to find out what the best ways are for you to boost your metabolism.
We'll also investigate a hidden danger lurking in your rice and ask, do we really need to push our bodies to the limit? # My voice just cooed # My mind let loose # Mm, Dr Love # Doctor, I want you # Ooh, Doctor Wanna Do # I can't get over you # Dr do anything that ya Wanna Do # Doctor, I want you # Mm, my Doctor Wanna Do # I can't get over you Dr do anything that ya Wanna Do.
But what's the health advice you can really trust? We're here to weigh up the evidence and use our expertise to guide you Through the contradictions and the confusions.
We do the research no-one else has done.
And put your health at the heart of what we do.
We listen to the questions you want answered.
And ensure you get the information you need.
We're here when you want to know the latest findings.
And not just the latest fads.
I'm Michael Mosley.
In this series, I'm joined by a team of doctors.
Together, we'll cut through the hype, the headlines and the health claims.
This is Trust Me I'm A Doctor.
Hello, and welcome to a new series of Trust Me I'm A Doctor.
This time we're coming from Inverness in the Highlands, where we're carrying out a fascinating experiment to see if consuming probiotics will change your gut bacteria and maybe even improve your health.
We'll also be finding out, can we lose weight while we sleep? And can red wine really help us live longer? We'll just have one more.
One more small one.
I'll discover how to beat the winter blues.
We'll witness a UK first, a UK surgery using 3-D printing.
I can see his heart! And we'll find out if going decaf is dangerous.
But first When it comes to losing weight, there are really two methods.
There's dieting and there's exercise.
I've come across reports that exercise makes us hungrier and more likely to snack on unhealthy treats afterwards, undoing all our good work.
So, we might be better off sticking to dieting.
But is that true? To find out, over the next two days we're running a study with the University of Bath.
We've enlisted sports scientist Dr Javier Gonzales and recruited ten hungry volunteers who are getting ready to diet or exercise.
Yeah, I think exercising will make you hungrier.
I think after a few hours, the hunger will definitely kick in.
I just think dieting always makes me hungry.
Because when you've been exercising, you know, it takes your mind off your hunger.
First, we find out how hungry everyone in the group is on a typical day.
They all do no exercise and eat the same amount of food for breakfast.
Over the next three hours, they all rate how hungry they feel on a questionnaire.
And we're doing some blood tests to get some baseline measurements as a control.
On day two, we split them into two groups.
Diet and exercise.
Before breakfast, the exercise group are burning off 500 calories.
Which is between ten and 18 laps, depending on their body weight.
Great stuff.
Keep pushing.
Meanwhile, our dieters are engaged in much more restful activities.
Great job.
Breakfast time, and it's the dieters' turn to suffer.
They get 500 calories less to eat.
Over the next three hours, we're testing which group gets hungrier.
Again, they rate how hungry they feel.
Just hold that there for me.
And we repeat the blood test.
We're looking at the levels of a hormone called ghrelin.
Why are you focusing on ghrelin? There are many hormones that influence appetite.
Many of these are secreted by our gut.
The interesting thing about ghrelin is it's the only one we know of that stimulates appetite.
All of the other hormones seem to suppress appetite.
And when you have higher ghrelin, what does that mean? So, more ghrelin equals more hunger.
OK.
And what we're going to be looking at is whether exercise, or dieting, affects it more.
When I do exercise, I feel hungrier.
You may perceive that, but we'll find out today.
- If that's true.
OK.
- Yeah.
Once Javier's analysed the data, we gather to find out what he's discovered.
OK.
Results time.
- What did you find? - Let's have a look.
Wahey! So, these are the self-reported ratings of your appetite, compared to your control conditions.
So, on average, the diet group felt hungrier, compared to the exercise group.
Did you all feel hungry afterwards? - Very hungry.
- Super hungry.
Very hungry.
Yeah.
So, there were no exceptions in this group? - No.
- No.
- OK.
I must admit, I was surprised by how big a difference it was between these two groups.
And did people feel less hungry? Yeah, so I felt really, really hungry before the run in the morning.
But then, after the run, I didn't feel particularly hungry and, actually, I wasn't nearly as hungry as I'd been before.
So, on average, the dieters felt hungrier than the exercises.
But what about their levels of hunger hormone ghrelin? First, the exercise group.
On the left is their ghrelin level on the control day.
On the right, the level on the day they burned 500 calories by running.
We've got the exercise group, where you can see there's not much difference in ghrelin concentrations, compared to control.
But for the dieters who consumed 500 calories less, it's a different story.
Poor old dieters getting less calories there and their ghrelin levels going up and it's shouting at you, "Feed me! Feed me!" What's interesting is, it's completely consistent with your questionnaire.
- Yes.
- So, if you do the exercise, it's going to give you lots of benefits, It's not necessarily going to increase your appetite.
- Yeah.
- Anyway, I think you've all been patient long enough.
Please tuck in.
Hooray! So, the good news is that our study adds to a body of research which suggests that doing exercise is not going to make you hungrier.
So, if you combine it with a little bit of calorie restriction, there's a very good chance that you will not only get healthier, but you will also lose weight.
That is a win-win.
Now, it's always a struggle to cut back on the good things in life, not least the booze.
Do we really have to? Over to Dr Chris van Tulleken.
Many of us have the evidence of lived experience that alcohol makes you clever, charming and more attractive to the opposite sex.
Unfortunately, there is the more powerful evidence of robust science which says that even small amounts of alcohol are pretty bad for you.
But there is one drink which claims to be an exception.
Red wine.
We're endlessly bombarded with news reports telling us it might be just a little virtuous.
It's a part of the Mediterranean diet which is meant to make you live longer.
We know that it's not the alcohol that's responsible for the supposed health benefits of red wine.
But could there be something else in here that offsets the harm caused by the alcohol? Red wine is thought to be good for you because it's made using the grape skin, which contains a family of chemicals called polyphenols.
These have been the source of intense study for decades and one has been probed more than most.
Resveratrol.
Now, we've known about this chemical for a long time, but it wasn't until the 1990s that it was discovered in red wine.
So, why has it got scientists so excited? This is an East African killifish.
Let's call him Arthur.
Arthur is a handsome beast, but sadly, his time on this Earth is short.
Just a few months.
But that's useful for scientists who study longevity.
So, the scientists ran an experiment to see if giving resveratrol to fish like Arthur made them live longer.
What they found was that the fish in the experiment given the resveratrol lived up to 40% longer.
Now, that's pretty astonishing if you're an African killifish.
What you'll find if you read beyond those headlines that say something like, "A glass of red wine a day keeps the doctor away," is that at the bottom of the article, it will say that the experiments were actually done on a fish like Arthur, a worm, a fruit fly, or sometimes just cells in a dish.
So, although the research may be promising, it doesn't amount to evidence that red wine may have health benefits that means you and I will live any longer.
And even if we do one day discover that resveratrol has a significant beneficial effect on people, there's still a catch when it comes to getting it from wine.
This is a glass of Pinot noir, it happens to be from the Yarra Valley in Australia.
Now, Pinot noir is a light red with low acidity, medium tannins and some of the highest levels of resveratrol of any wine in the world, at about 10mg per litre.
Unfortunately, though, most of the studies on resveratrol have been done using capsules, like this.
And in order to get as much resveratrol out of my wine as there is in this capsule, I would need to drink all of these bottles here.
So, I'd better get going.
So, despite many years of research, we're still not entirely sure what lies behind red wine's healthy reputation.
And it may well be that we've been looking at it the wrong way.
When drunk in moderation as part of the Mediterranean diet, red wine accompanies nutrient-rich foods, like fruits, vegetables, fish and nuts.
And the evidence suggests that it's the diet taken as a whole that leads to a longer, healthier life.
Now, having one small glass of red wine with food is not going to do you any harm, but you have to ask yourself honestly, when was the last time you did that? If you're anything like me, you have one glass over dinner and then probably another glass over dinner, then you finish off the bottle in front of the television with dessert.
So, sadly, red wine is not some kind of delicious medicine where the more you drink, the better it is for you.
I will just have one more.
One more small one.
SNEEZE Every year in the UK, we spend over ç¿700 million on probiotic products that promise to improve our health by enhancing the mix of bacteria in our gut.
More and more research is showing how our gut bacteria influence every aspect of our health.
And yet, there is still so much that we don't know about this inner ecosystem.
If you believe the hype, our gut bacteria can help tackle a dizzying array of disorders.
From poor digestion and bowel diseases to allergies, acne, obesity, and even mental health problems.
Popular probiotic products say they can alter our gut bacteria for the better.
But do they actually work? Probiotics are essentially supposed to work in the opposite way to antibiotics.
Instead of killing harmful bacteria, it it's claim they add new, beneficial bacteria to the complex swamp of microbes that already live in our intestine.
However, there's a catch.
Before the bacteria in probiotic products can change our gut for the better, they have to survive the perilous journey through the acid bath that is our stomach and set up home in the intestines.
How well they can really do this is a hot topic right now and is exactly the kind of thing that Trust Me likes to test.
So, with the help of NHS Highlands, we've enrolled 30 residents of Inverness who are going to volunteer their guts in the name of science.
We split our volunteers into three groups.
They'll be helping us test a market leading probiotic against some alternatives.
All closely scrutinised by Dr Adele Costabile of Roehampton University.
Our first group will be taking a daily dose of a top-selling probiotic yoghurt, available in most supermarkets.
Products like these are specially formulated to contain particular bacteria strains thought to be beneficial.
This yoghurt contains just one specific bacteria.
One specific bug that can help your gut to make a little bit healthier.
However, some researchers claim these drinks don't work.
They think our stomach acid, which kills off harmful bacteria, is also killing the good bacteria in these products.
So, will our volunteers see any difference? Our next group are trying a different type of probiotic.
A fermented milk drink called kefir.
It's long been a traditional part of the diet in Central Asia, but it's recently started to appear in our supermarkets.
This stuff naturally contains dozens of strains of live bacteria, way more than the familiar yoghurt drinks.
Kefir has been in our diet for several hundred years.
It doesn't contain only one species, but contains more bacteria, plus some yeast.
But does having more bacteria make it more likely that some will survive our stomach acid? In four weeks' time, we should see if these bacteria have managed to make a new home for themselves within your gut.
But to avoid the problem of stomach acid altogether, our final group will try a different way to boost their gut bacteria.
Instead of taking a probiotic, they'll be given what's called prebiotic diet - foods that contain a type of fibre that the good bacteria already in our gut thrive on.
It's a fibre that can target the good guys that are already down there in your digestive system.
The prebiotic fibre we're going to test is one that's readily available in common veg.
It's called inulin and it's found in leeks, onions, garlic, asparagus and Jerusalem artichokes.
I got the inulin.
Soup is the way to go, maybe some stir-fries.
I don't know.
I think variety's the thing, isn't it? I got kefir, which I've never heard of before.
So, I'm interested to see what it tastes like.
I got the yoghurt drink.
The advert says that they did you good, so I tried them.
I didn't notice any difference.
So, that's why I'm doing this trial, because I want to know, do they work or not? Before our volunteers start the experiment, we're taking urine and stool samples which will allow us to test the volume and variety of their existing bacteria.
In four weeks' time, we will test our volunteers again to see if there've been any changes to their guts.
Many of us would like to be able to cut back on our calories, but we find it hard to do.
GP Dr Zoe Williams has been investigating a surprising way to do this without even noticing.
When it comes to keeping our weight in check, we naturally turn to diet and exercise, but intriguing research suggests that there may be an easier way.
Surprisingly, getting enough sleep could make all the difference.
On a cold, dark night, we've invited four volunteers into the Kent countryside.
We're going to test a recent research claim that suggests the amount they sleep will affect how much they eat.
So, we're giving them something that will keep them up all night.
Oh, my God! The hairs! Oh, it's holding my finger, look.
These pretend babies are designed to cry a lot.
I can't do it! We've told our volunteers that we're looking into sleep, so they have no idea that we're really going to measure how their lack of sleep affects their food intake.
I'm going to be watching their progress with sleep expert Dr Denise Robertson from the University of Surrey.
Sleep interacts with every other aspect of your life.
So, sleep is going to affect your ability to make good food choices, your ability to, sort of, resist snacks.
It's bedtime for our volunteers.
But not for long.
BABY CRYING A bad night's sleep disrupts two key hormones that play a role in hunger.
One, we heard about earlier in programme, ghrelin.
You see an increase in ghrelin.
And ghrelin is a hormone that's been linked to food intake.
It drives your hunger.
The other has the opposite effect, signalling when we're full.
It's called leptin.
At the same time, you'd see a suppression of leptin and leptin is a satiety signal.
- OK.
- So the combination of hunger going up, satiety going down, you'd expect them to feel physically more hungry.
The morning after the night before.
This is the thirstiest baby in the world.
I've had, maybe, three or four hours' sleep.
For breakfast, we laid on a spread of healthy and not-so-healthy foods.
Look, the granola's going down well.
- Yeah.
- And the pastries are very popular.
What you would expect is things like pain au chocolat, for example, because it's high-fat, it's high sugar, you could almost expect to see them going back for seconds or thirds if they were sleep deprived.
Rather than hitting the bananas and the apples.
As a comparison, we also gave our volunteers a night of normal, undisturbed sleep and, again, in the morning, counted the calories.
Knowing the calorie content of each food, Denise is using our footage to tot up each person's total.
And it's time for the results.
Hi, guys.
It's good news.
You're all very good parents, except for one person.
- Ronan.
- We knew it! But we're not really interested in that, because that's not really what we were looking at, at all.
They were actually monitoring how much you ate.
Because we're interested to know if the amount of sleep you get affects how much food you put on your plate.
- Mm.
- OK.
- And what we found is Ellie and Bertie, you had quite a quite a difference in your sleep.
You were losing three and a half or four hours.
You did respond to the sleep loss, actually, you ate considerably more.
You just let yourself go for it.
Overall, Ellie ate 57 calories more at breakfast when she was tired.
While Bertie ate 108 calories more.
Eating 100 extra calories every day is enough to make you put on 5kg in weight over a year.
Ronan barely slept a wink and whilst he didn't eat more, he did choose more sugary foods.
But the person who got the most sleep responded rather differently.
Howie, you managed to sleep quite well.
- Yeah.
- Even with the baby.
- I was.
- You just ignored her.
No, I didn't ignore her.
Interestingly, after his good night's sleep, Howie's eating habits were unaffected.
These experiences are consistent with an analysis by King's College London that reviewed dozens of smaller studies involving sleep and appetite.
It showed that although not everyone is affected in the same way, on average, getting less than seven hours of sleep night led to people eating significantly more overall.
These guys are going to go back home where they don't have babies.
What can they do to make sure that they have a good night's sleep? You would have blackout blinds.
You would make sure the room wasn't too hot.
You'd want to take out the laptop, the tablet, the mobile phone.
I guess one way of thinking about it is that the bedroom is for two things and two things only.
One of those is sleep and You can probably work out the other one.
Although Ronan looks confused.
So, if you're struggling with your weight, then it's well worth considering not just your diet and exercise, though they're important, but also think about how much sleep you're getting.
Aim for at least seven hours per night and not only will you feel better, but you'll be more able to resist those sugary treats.
For information on how to get a better night's sleep, visit Lots of you have been sending in your health questions.
And we've been getting you answers.
What is gout and what can I do to avoid it? Gout is actually a form of arthritis causing pain in the joints, and it's on the increase, thought to be due to an ageing population and rising obesity.
It currently affects around a million people in the UK.
Gout can affect any joint, but typically it starts here, in the big toe.
Now, what causes it is the build-up of a substance called uric acid.
And if your kidneys don't clear it, then you get deposition of crystals in the joints.
And that's what causes all the pain and inflammation.
But research has shown that there are things you can do to help avoid developing it.
Now, gout is associated with being overweight, which is perhaps why it's becoming more common.
The particularly bad form of fat is the visceral fat you get around your gut, which seems to block the clearance of uric acid.
The good news is, if you lose weight then you'll see a rapid improvement in your gout.
But there are also specific foods and drinks to avoid if you're prone to gout.
Any drinks with lots of sugar, even fruit juices, are out.
Instead, you should drink plenty of good old-fashioned water.
Alcohol can raise uric acid levels too.
And some foods contain a high level of proteins called purines, which our body breaks down into uric acid.
Red meats and poultry are OK in moderation, but it's best to avoid seafood and gamey meat.
On the other hand, skimmed milk, water and low-fat yoghurt actually seem to help.
Along with plenty of fruit and veg, of course.
If you do develop gout in a joint, rest and ice can help.
Anti-inflammatories, like ibuprofen or naproxen, can reduce inflammation and pain.
Aspirin's OK in low doses, but if you're taking more than 75mg a day, it can actually increase your uric acid levels.
Your GP can give more advice and treatment options.
Your doctor may decide to inject your joint with steroids or perhaps give you medication to balance out the uric acid levels.
Either way, hopefully it'll get you back on your feet and pain-free.
Now and again, a new bit of technology emerges in a completely unrelated field, like engineering or design, which has the potential to transform an area of medicine.
Surgeon Gabriel Weston has been following one such story and has witnessed an operation, the first of its kind in the UK.
Edward Evans had always been a keen sportsman and coach.
But one day, seven years ago, when he was 54, he began to experience a pain that would change his life.
I come down on most Sundays to watch my sons play rugby, and on this particular Sunday, I started to feel a dull ache in the centre of the chest.
What Edward was feeling was a rare infection that had taken hold in his sternum - the bone at the centre of his ribcage.
This made him extremely unwell.
Doctors had no option to remove his sternum.
Replacing it with an implant wasn't an option at the time because any foreign body inserted when Edward was already so ill carried a high risk of further infection.
All the surgeons could do was cover the gap with some of Edward's own muscle, leaving his heart and lungs so vulnerable that a blow to his chest could be fatal.
I was playing five-a-side up until that point, teaching the boys to play rugby on and off.
So, that Stopped doing that.
And I miss it.
I like to keep active.
I want to keep fit.
I want to cycle, I want to walk.
In my mind, there's a massive correlation between keeping fit and feeling strong and feeling old.
Edward could continue to live without a sternum, but his vulnerability is limiting his quality of life.
Over time, his body has recovered from the infection, which means that surgery would be less risky.
And he's been offered a new kind of implant that's never been tried in the UK.
Normally, the only option for people like this would be an implant made out of mesh and cement.
But what Edward's about to receive is completely different.
It's a titanium sternum made especially for him and 3-D printed on the other side of the world.
CT scans of Edward's chest have been sent to Anatomics in Melbourne, Australia.
World leaders in the design and production of bespoke surgical implants.
Their designs are loaded into the 3-D printer which has a chamber filled with powdered titanium and an electron beam which fuses the particles together, layer by layer.
And now, it has printed Edward's new sternum.
The loose powder is blown away, revealing the implant for the first time.
The titanium is light, strong and rigid, and less susceptible to infection than cement.
The finished sternum will be implanted at the Heartlands Hospital in Birmingham, by thoracic surgeon Mr Ehab Bishay.
They, in fact, have reconstructed the defect to match completely what we took out.
It will protect the underlying structures.
The thing that we cannot tell you is whether it will improve your lung function, the mechanics of your breathing.
- OK.
- You're a pioneer.
And hopefully, you'll show the advantages of something like that.
The procedure begins with the plastic surgeon, Mr Khalil, taking down the muscle flap that was used to cover the defect several years ago.
The structures that these gentlemen are operating up against are the very structures which keep us all alive.
What Mr Khalil has already found is that the muscle has become very thin, so he's coming to the lung much more quickly than he'd anticipated.
Once Mr Khalil is finished, Mr Bishay will perform the delicate task of fitting the new sternum into place.
Normally, we would have to mould the cement ourselves, by hand, handling it.
So, the risk of infection is increased.
Here, you've got some that's ready-made, should slot in.
You might not see that today, because, obviously, this is our first time using this technique, but I have faith in the fact that it's been reconstructed so precisely.
In order for Mr Bishay to get the outside of the implant going over each rib head, he's had to ask his anaesthetic colleague to deflate the lung on purpose.
Now, the implant will be tried in situ for the first time.
There's an enormous amount of surgical skill and adjustment that comes into play, trying to make it perfectly fit, where it will hopefully stay for the rest of Edward's life.
OK.
At last, the perfect fit is achieved.
It's an amazing thing to see and it's now just for Mr Bishay to fix it there with screws.
Although the operation has gone smoothly, it remains to be seen how well the implant will function for Edward.
Several weeks later, Edward has recovered from the procedure and it's time to find out.
Throughout this process, Dr Nicola Oswald has been using motion capture and cameras to monitor Edward's breathing and movement.
Past 100.
Well done, keep going.
So, has the implant made any difference? This was before surgery.
And you can see when he takes a breath in, that the ribcage moves in rather than moving out, like you expect, - taking a deep breath.
- How does that compare with the one after surgery? The overall shape of the chest looks more normal.
Then when he takes a deep breath in there, the ribcage moves out in time with him breathing in and then back in, in time with him breathing out.
So, it's gone back into synchrony again.
These results are extremely encouraging and could pave the way towards even larger and more complicated implants.
So, what's the main difference for you, Edward, now compared to before? I feel confident now.
It feels like, probably, how I felt when my chest was was normal.
Whatever I do, simple or difficult, you know, I feel better doing it.
I can fall over with confidence, basically.
That's the truth! Coming up - how to spot an asthma attack and save a life.
And can decaffeinated coffee actually be bad for you? But first Four weeks ago, we started an experiment in Inverness to see if probiotic products are really the best way to improve the mix of healthy bacteria in your gut.
30 volunteers have been trying one of the three options.
Our first group have been taking a market-leading probiotic yoghurt drink.
These drinks are formulated to contain one or two specific types of bacteria that manufacturers know to be beneficial.
I was taking probiotic yoghurt.
And how was that for you? Personally, I thought my health improved.
Our second group have been taking a traditional drink called kefir, made by fermenting milk, which makes it naturally full of different types of live bacteria.
It was quite an acquired taste to begin with, because it's very sour.
But I got used to that.
And our third group have been on what's called a prebiotic diet, rich in the type of fibre called inulin, thought to boost the good bacteria already in our gut.
It was fine.
It was a bit of a challenge on some days.
I love leeks, I love artichokes, I love asparagus, but there's only so much you can eat in a day.
Dr Adele Costabile now has the delightful job of analysing our volunteers' stool samples.
This will reveal whether any of our methods have improved the mix of bacteria in our volunteers' guts.
First, the probiotic yoghurt.
This group saw a promising change in the levels of bacteria that had been linked to obesity.
This is consistent with other, bigger studies that suggest a range of benefits, particularly in treating specific gut conditions.
Next, the group who were on the diet rich in the fibre inulin.
In our trial, this group saw a rise in one bacteria type known to be good for maintaining gut health.
And this again is consistent with other studies that have shown inulin to be beneficial.
But our most significant result was in the group taking the fermented milk drink, kefir.
We saw for this group differences between before and after the four weeks' treatment.
We saw a beneficial effect.
Basically, the good guys down there in your gut, they were different compared with the beginning.
This is something promising.
Our kefir group saw a rise in a whole family of bacteria called lactobacillus.
These bacteria are thought to be good for general gut health and they're known to help certain conditions, including traveller's diarrhoea and lactose intolerance.
So, in our trial, amazingly, it was the fermented drink, kefir, that most of our volunteers had never even heard of before, that actually caused the most changes to their gut bacteria.
I would actively be interested in trying the kefir drink, just to see the results of that.
Andy, were you surprised by the results of the kefir? The fact that it was this fermented drink with maybe quite a variety of bacteria made me think it would have an affect.
Now, the kefir was such a clear winner in our test that we want to find out more.
What makes it so full of healthy bacteria, and are there other foods like it we should all be eating? This smells really nice.
More on that later in the programme.
The winter months can play havoc with our health.
Colds, flu, joint pain and even heart attacks are more common.
But is it also messing with our minds, giving us the winter blues? SAD, seasonal affective disorder, is also known as winter depression, but tends to come on during the winter months.
Now, common symptoms include tiredness, low mood, a craving for carbs and weight gain.
In some cases, it leads to severe depression.
SAD was first recognised in the early 1980s.
Since then, it has become an accepted medical condition and it makes the headlines most winters.
A recent survey found a third of us think we might suffer from it.
So, how do you know if you've got it? How do you treat it? Should I worry about SAD? Personally, I've not thought much about SAD, since I'm pretty sure it's something I've never experienced.
But I'm putting that assumption to the test.
I'm having my SAD potential assessed by Dr Brenda McMullen, a neurobiologist and psychiatrist from Copenhagen University Hospital.
I start with a questionnaire, the basis of most mental health assessments.
This asks about my mood and behaviour through the year.
For a full diagnosis, it would usually be followed by an interview with a psychiatrist.
So, what do my answers reveal? You mention in this that you have changes in all of the items that we look for in a person who suffers from seasonal affective disorder.
So you say here you've experienced changes in the length of your sleep, in your appetite, in your weight, in your social activity and in your energy levels.
It seems like you are feeling the best in August and July and you are feeling worse, gaining most weight, sleeping most in December.
Yes.
I was surprised when I started to fill it in, I started to realise I probably I do have shades of seasonal affective disorder, which is something I hadn't really thought about before.
Where would I fall in terms of the average, do you think? You are worse off than average.
It's 11.
A maximum of 24.
So, you're in the middle range, but on average is probably closer to six or seven.
How common is it? Seasonal affective disorder is not something that you either definitely have or do not have.
It is a spectrum.
So, many people would have some degree of seasonality, but not being depressed at all.
And you would have probably 5% having a depression and maybe 5% having no symptoms at all.
So, like a lot of people, I have some SAD symptoms.
But I'm not amongst the small percentage who've been diagnosed with severe seasonal affective disorder.
Those patients have been the subject of Brenda's research.
Using brain scans, she noticed a difference in brain activity suggesting they were being deprived of serotonin, a chemical that is thought to regulate mood and appetite.
Although we're not sure why this happens, it seems the seasons can affect us much more powerfully than I had realised.
Now, that was a big surprise.
I've known for a long time that I do not like dark, wet, wintry days, but I never imagined that I might have SAD.
It certainly means I am intensely curious to find out more.
To understand the condition better, I'm meeting Professor Anna Wirz-Justice from the University of Basel, Switzerland, who has been researching this condition for decades.
So, what are the main theories about the causes of SAD? There are two aspects that are important.
If we go back to basic biology of seasonality, it is the day length that triggers certain changes in physiology and behaviour.
Hibernation in winter, adding weight, eating a lot more, sleeping longer.
And the other one is that we don't get enough light to set the biological clock to synchronise our rhythms to 24 hours and, therefore, they drift later and later.
And if you have a late clock, you are more vulnerable to depression.
In what ways is light resetting the clock? The last 15 years has been a revolution in that a new kind of photoreceptor was found in the eye which is sensitive to light.
These photoreceptors transmit directly to the biological clock in the brain - information that it's dawn or dusk, that it's light or dark.
By having light in the morning, you are regularising all your rhythms in your body, they are all getting synchronised.
Right, so it goes straight in there, just sort of And goes, click! And says your biological clock is now awake and functioning.
So, what sort of treatments are available for SAD? Light is the treatment of choice, of course.
With or without antidepressants.
And the third, the different psychological treatments.
One of my main messages for anyone who suffers from the winter blues or from winter depression, is the easiest treatment would be a regular walk outside.
Most of the studies show that light in the morning is better.
So, if I just sit around my house, I'm not going to get it just from, sort of, overhead lighting - or things like that? - No, you are not.
- You need special lamps.
- You go outside.
OK.
It's cheaper.
Is there any value in buying a light box? A light box is the most reliable method of treatment.
You have it in your house and you sit in front of it for half an hour every day.
So, have you seen a lot of lives transformed by light? A great many people.
They finally have a diagnosis and they have a treatment that is fairly straightforward and it works rather quickly, within one or two weeks.
And I think one of the important things for light therapy, you are treating yourself before you sink really into this winter depression.
Speaking to our experts has been a real eye-opener.
I was surprised to discover there was a spectrum of winter depression on which we might all find ourselves.
So, should I worry about SAD? Well, it turns out I should.
And should you worry about it? Well, that depends on whether you regularly get the winter blues or not.
If you do, then the answer is simple.
Light.
Go out for a morning stroll, and it's important it is done in the morning, or invest in a light box.
For more information, go to the Trust Me website where you can also try a questionnaire to see if you have any symptoms of seasonal affective disorder.
If you do have health questions you've always wanted answered, then do send them to us via our website.
I've heard that decaf coffee is full of the chemical used in the removal process, so it's best avoided.
Is this true? These days, people are turning away from traditional coffee to decaffeinated options instead.
Even in the case of posh coffees, like this one.
And that's because some of them think that it is a healthier option.
But is it? The first thing to look into is how decaf coffee is made.
There have been reports in the media claiming that some of the methods used to remove the caffeine involved substances that are actually bad for us.
All decaffeination methods start with this.
The green, or unroasted coffee bean.
Most methods use water to get the caffeine out of the bean.
Then a chemical solvent is often used to get the caffeine out of the water.
The solvent is then removed and the remaining water is dried off.
There are two possible chemical solvents that can be used in this process - both of them, technically speaking, toxic.
But by the time the process is complete, they're found at such vanishingly low levels that they are below the European regulated safe limit.
But to avoid any solvents, there are other methods that some manufacturers use to remove the caffeine.
One alternative uses a charcoal filter.
Another uses carbon dioxide at extremely high pressures.
So, you can choose solvent-free coffee if you want.
But there's not any evidence that it's actually healthier.
Now, coffee aficionados will tell you at great length, of course, that the method used to decaffeinate coffee can affect the taste.
So if you really worry about these things, then I would be guided by your taste buds and don't sweat about the methods used to produce the coffee.
There is, however, something else that you should be aware of if you're thinking of going decaf.
Your decaf may not contain any chemical nasties, but you might be surprised to know that it probably does contain some caffeine.
A 2006 study conducted in Florida found that nine out of the ten decafs they tested had at least some caffeine in them.
So, the two-shot decaf latte that you're drinking might contain as much caffeine as a can of Coke.
For most of us, though, if you're worried about what your daily cuppa's doing to your health, there's something other than caffeine you might want to think about.
A cup of black coffee is virtually calorie free.
Add milk and sugar, it goes up to about 50 calories.
But by the time you're looking at one of these, a giant mocha latte, it can be up to 500 calories.
The same as a big burger or a large piece of cake.
So, caffeinated or not, you can enjoy a small cup with an easy conscience.
But treat this as a treat.
Asthma is one of those things we associate with childhood, yet one in 12 adults are also affected.
We think of it as mild, and yet it can be life-threatening.
Which is why it is so important to be able to recognise the signs and the symptoms.
Over to Dr Saleyha Ahsan.
There are over 5.
5 million people with asthma in the UK and every year around 1,000 of them will lose their lives to an asthma attack.
But if more people knew the warning signs, some of these deaths could be prevented.
My brother has had asthma all his life.
My father got it as an adult and has needed intensive care.
His brother, my uncle, died of it.
That's why I'm so keen to talk about the signs and symptoms of asthma, so that people can spot a dangerous attack quickly and save lives.
Asthma is a condition that affects the airways, the tubes that carry air in and out of the lungs.
If these become irritated, that can lead to inflammation of the airways, the muscles tighten and the tubes narrow.
And this causes shortness of breath, wheezing, and it can even lead to a life-threatening asthma attack, needing hospitalisation.
We still don't know what causes asthma in the first place, but for those who have it, there are many things that can trigger an episode.
And even emotions and stress.
Another surprisingly common trigger is exercise.
But despite that, doctors actually recommend it for asthma, especially swimming, as it can calm and regulate breathing.
So, I've come to an outdoor swimming club in Kent.
I dipped my toe in and the water's freezing.
A few of the members here have asthma.
Describing their experiences help others recognise the symptoms.
It feels like a tightening in your chest.
It doesn't matter how many times you breathe in, or how deeply you breathe in.
It stops you sleeping, I cough a lot in the night.
My breath shortens and I think I'm not getting the air out of my lungs and, therefore, I find it hard to get the air back in again.
To show the non-sufferers in the group what asthma actually feels like, we've set up a demonstration with the help of Dr John Dickinson and a device that impedes your breathing in a way that mimics asthma.
When the non-asthmatics put this in their mouth, they'll find it pretty easy to breathe in - Yeah.
- But they'll find it pretty hard to breathe out and that's what happens in asthma.
Just think how long it takes to empty your lungs, think about that asthma response.
You can see how easy it is to get panicky when you're feeling like that, to start hyperventilating.
That's horrible.
That is actually horrible, because you can't get breath out - and you're already wanting to breathe back in.
- Exactly.
Feel how much longer it takes to breathe out.
- What did you think? - It's hideous.
- Yeah.
- It's horrible.
That's using all your muscles.
That's huge exercise.
You all right? - Horrible.
- Yeah.
- Yeah.
I'm having a lot of sympathy and empathy for you guys right now.
I really am.
'Anyone who has asthma should always carry an inhaler, 'a spray containing a muscle relaxant to open up the airways 'and ease breathing.
'If you see someone struggling with asthma, 'you can assist by keeping them calm because this can help bring 'their breathing under control.
'But sometimes, if the symptoms continue, 'things can become much more serious.
' Every ten seconds, someone is having a life-threatening asthma attack.
So, what are the warning signs? The person is extremely breathless, perhaps struggling to speak.
Their symptoms are getting worse.
Their asthma inhaler isn't helping.
Children may complain of a tummy ache.
If an asthma attack continues untreated, the lack of oxygen can be fatal, but there are things you can do to help.
So, if someone is having an asthma attack, follow these instructions.
Keep them and yourself calm.
Sit them upright.
Make sure that you've located their inhaler.
Get them to take one puff of their inhaler every 30 to 60 seconds.
It can feel like a long time in between, but it's the right thing.
Repeat up to a maximum of ten puffs.
Take another puff of that, please.
Excellent, well done.
If they didn't have their inhaler with them on the day, - what would you do then? - Call 999 straightaway.
You should also call an ambulance if they don't feel better after ten puffs, or if they're a child.
If, in an extreme situation, the patient stops breathing and their heart stops, you must start CPR immediately and don't stop until the ambulance arrives.
Nice and easy.
Nice and calm.
If you have asthma, learn to recognise your triggers and always carry your inhaler.
Make a plan with your GP of what to do if you have an asthma attack.
And for the rest of us, we should learn to recognise the warning signs of an asthma attack, particularly for children.
Wheezing, shortness of breath, they are unable to finish a sentence without having to breathe, and sometimes children complain of a tummy ache.
For a list of symptoms and more, check out Earlier in the programme, we did a big experiment to test three different ways to boost the good bacteria in our gut.
The surprise winner was a little-known drink called kefir, made by fermenting milk.
Having discovered in our trial that fermented foods worked best, we wanted to look at the subject in greater depth.
What exactly is going on when food is fermented, and should we all be eating more of these foods? To find out, I first need to take a closer look.
Fermentation is the process by which bacteria and yeast turn carbohydrate into things like gases, acids and alcohol.
Now, we are familiar with the idea you need micro-organisms to produce your beer and wine, but until fridges were invented, it was actually one of the main ways to preserve foods.
Fermented foods include pickled vegetables, cheese, chutneys, sourdough bread, soy sauce and drinks like kefir.
And it turns out, they're surprisingly good for us because the way they're made encourages the growth of helpful bacteria.
Anna, Simon and Gabba all regularly make fermented foods and drinks using traditional methods.
Today, Anna is making some soft cheese and Kombucha, a fermented tea-based drink.
I'm using the culture to make it.
Simon is making sauerkraut - preserved white cabbage - and kefir, the milk-based drink that did so well in our trial.
You just get these grains.
Put them in with milk.
And Gabba is making kimchi, a traditional Korean dish of fermented vegetables.
When you try it, it's just fire! There are different methods, but a common one is to chop up vegetables and leave them in a salty liquid.
Over time, the salt kills off the bad bacteria, allowing good bugs like lactobacillus to thrive.
These bacteria produce lactic acid which preserves the vegetables and gives the food its distinctive flavour and aroma.
Polish Korean kimchi.
Here we go.
Here.
- Spicy.
- It's spicy.
Whaa Ooh! But if you don't have time to ferment at home, these foods are increasingly available in supermarkets.
I want to see how the amount of healthy bacteria in them compares.
What we're going to do is we going to take these home-made fermented foods and we're also going to get the shop-bought equivalent.
We're going to send them all off to a laboratory to be analysed.
Now, I know which I prefer, from the point of view of smell, taste and texture, but it will be extremely interesting to see how the bacterial content of these foods compare to those which you can buy in the shops.
Scientists at the University of Roehampton have placed samples from each product on petri dishes and are painstakingly counting any helpful bacteria that grow.
To discuss the result, we brought in the leading expert in fermented food and gut bacteria, Dr Paul Cotter from the Teagasc Food Research Centre in Cork.
So, what are the results showing? So, in the kimchi, the sauerkraut, cheese, kefir and Kombucha, from the home-made products in the blue, you're seeing quite high levels of bacteria, particularly lactobacillus bacteria.
And in a commercially sourced products, you're only seeing those lactobacillus present in the kefir and Kombucha.
These commercial providers presumably used a more traditional fermented food processing or preparation.
Some commercially-produced foods will be pasteurised in order to make sure they're safe and to give them a long shelf life, But during that process, you're also killing the good bacteria along the way.
Is there much evidence that lactobacillus, if you take it in the form of a preserved food, is actually good for your health? It depends on which lactobacillus are present.
There are many different species and even within a particular species, there are different strains, some of which have good properties and others which don't.
And I suppose that's why, in the case of probiotics, people will have studied an individual strain and know a lot about it.
But by eating a fermented food with lots of different varieties, at least there's a chance that some of them in there will be good for you.
So, for general good gut health and to acquire a range of helpful bacteria, fermented foods are an excellent way forward.
And our tests suggest that you'll find more of these helpful bacteria in traditionally-made fermented foods.
But if you want to make your own, then do follow a recipe and make sure your hands, jars and raw ingredients are clean.
I think the key thing if you are making it at home is it's safe and you're not encouraging the growth of disease-causing or spoilage microbes.
So, you need to have good-quality raw material, you need to have a recipe, correct ingredients, follow the recipe so that you're not storing it too long or at the wrong temperature.
And I think in those circumstances, you can't go too far wrong.
The biome, the gut bacteria, is clearly a really hot area of research and there is obviously still an awful lot that we need to learn.
That said, I am convinced that fermented foods are good for the gut.
In fact, I am going to go home now and make my own kefir.
That's it from Inverness.
Next time, we're in Walsall, where we're doing a really fascinating experiment to find out what the best ways are for you to boost your metabolism.
We'll also investigate a hidden danger lurking in your rice and ask, do we really need to push our bodies to the limit? # My voice just cooed # My mind let loose # Mm, Dr Love # Doctor, I want you # Ooh, Doctor Wanna Do # I can't get over you # Dr do anything that ya Wanna Do # Doctor, I want you # Mm, my Doctor Wanna Do # I can't get over you Dr do anything that ya Wanna Do.