Hello, and welcome to the Microbiome Medics Podcast.

I'm Dr.

Siobhan McCormack.

And I'm Dr.

Sheena Fraser, and we're your co-hosts.

We are both GPs and lifestyle medics with a shared passion for microbiome science.

We'll be translating the evidence and packaging it into actionable, bite-sized chunks so that you could harness the power of the microbiome to improve your own health and that of your patients.

Hello, everyone, and a very warm welcome to this episode of Microbiome Medics Podcast.

Today, we are talking all things flatulence.

And I'm here with my good buddy, Sheena Fraser.

Hi, Sheena.

Hi, Sheena.

How are you doing?

I'm good.

It's really nice doing a podcast with you again.

It's been a while.

So I insisted on talking about farts for an hour.

I sent Sheena an email.

It was on the back of the Traitors episode, which many of you will have seen if you watch the whole thing or just the section that went viral when Celia Imri did a fart on live TV and it caused something of a sensation and it kind of went viral and everyone was talking about it the next day at work, even though I haven't seen Traitors.

Sheena, tell me you've watched Traitors.

So Shiv, everyone was talking about it except us because neither of us watched Traitors.

Well, this is ridiculous.

We need someone who's watched Traitors.

So I am glad that we have Julie Thompson here, lead dietitian and FODMAP expert.

Julie, welcome.

Oh, thank you for inviting me.

Yeah, so I didn't watch Traitors, but I was asked to comment on it.

So I do know about it.

So we have three people talking about the Traitors episode and none of us, this is useless.

Okay, I'm going to replay it for us and for anyone else who missed it.

And then, Julia, I'm going to get you to tell us how you were involved in it.

Welcome to the worst team-building away day experience in history.

What just happened?

I just farted, Claudia.

I'm so sorry.

I'm so sorry.

It's nerves, but I always own up.

I know.

I always own up too.

So that was it.

So tell us, Julie, you were actually contacted to comment on this.

I absolutely was.

And really, it was to comment about the fact that farts are normal.

Everybody does it.

I mean, it is incredible in 2025 when people are showing all sorts of things on TV that one simple, really quite quiet fart has caused this kind of, you know, TV sensation and has been awarded the sort of TV moment of the year.

So what were you asked about and what did you say?

So, it really was about sort of farting and, you know, about why we fart.

Okay.

So, it is a normal part of digestion.

Yeah.

And really about stigma.

So, we shouldn't be stigmatising farting.

We should own it like Celia.

Ah, well, she was impressive though.

She was, I mean, she just handled it beautifully.

Yeah.

Because although we're sitting here going, it's normal, I guess on live TV, in a room full of celebrities...

I mean, it could have been quite embarrassing and she did handle it beautifully.

She kind of owned it and turned it into kind of TV gold.

In fact, you know, I think that kind of that that simple fart has now been nominated for a BAFTA award.

And it's but it's going to start us talking about the science of farts.

So, Sheena, you're going to kick us off with, OK, what are farts and why do we fart?

And, you know, what are farts made up of?

Yes.

It's funny, isn't it, that we need an episode like that to tell us that farting is normal.

I think everybody in my family knows that farting is normal.

So yes, farting, it's gas.

Yes, it's gas that goes through us.

And several gases make up a fart.

Most of the gases are actually non-smelly or odourless gases, and the majority of the gas comes from bacterial microbial fermentation, and other gases come from just swallowed air, and that's a natural part of our digestion when we swallow air with the food, and that will travel through the gut.

But there is a little bit of debate over how much of that.

And I think, to be honest, it's likely to vary quite a lot between people and depending on their gut microbiome and their diet and their lifestyle as to how much of the gas, you know, the actual percentages are produced from these two different areas.

But the gases themselves are made up of nitrogen, oxygen, hydrogen, methane, carbon dioxide, and there's traces of sulfurous gases in there.

And sulfurous gases really are the smelly ones.

And they're the ones that we don't like when it comes to farts.

Yeah, absolutely.

I mean, you know, everyone's got their own signature.

It's like your own perfume and you can change it depending on what you're eating.

It's actually less than 1% of these farts are made up of these smelly gases that contain sulfur.

These are things like indole, skatel, hydrogen sulfide and volatile amines.

So the sulfur containing gases is the one that are particularly smelly and they're the ones that kind of linger around.

So even though they make up a small percentage of the actual the gaseous content of a fart they can be the ones that cause us kind of the most embarrassment but it's important to know that when scientists have looked into this they think you know on average people fart 10 to 30 times a day sometimes we know about it sometimes we don't we do it in our sleep and it can be up to, you know, much as, you know, one to two litres of gas are expelled each day.

So this is really kind of normal.

But the physics of farts is quite interesting.

And again, scientists have looked into this and you think of your intestines as your own sort of musical instrument.

It's your gut microbes talking to you.

So it depends the music or the noise that you make.

There can be very sort of strange noises.

They can sound very different.

And it depends on the volume of gas.

It depends on the sort of physics of your intestines and your anal area and your age and also just what you've been eating that day as well and I think we all kind of know that there are certain foods that can make us fart a lot more.

So Julie how do we know I mean we're saying farting's normal you know is there ever a time where you know either the smell or the volume of farts can be problematic or a sign of disease?

So I think really looking at sort of all the symptoms as well.

So if somebody is having excess gas, then, you know, if they're having that alongside changing bowel habit, diarrhoea or constipation, abdominal pain and other gut symptoms, then they really should be speaking to the GP about it.

So, Julie, I wonder if you could just give us a little background to your role as an expert dietitian in IBS and the low FODMAP diet.

Tell us a bit about what that is, the low FODMAP diet, where it came from, what it stands for.

Okay.

So this absolutely is a treatment for IBS.

It's not the only treatment.

And the FODMAP diet, essentially, so FODMAPs are prebiotic.

So a prebiotic defined as a substrate which is used selectively by our gut microbes to benefit the host.

So prebiotics, you know, if somebody hasn't got IBS, are a very good thing to include in the diet.

They help have a variety of gut microbes in our gut.

The difficulty is when it comes to IBS is that part of the cardinal symptoms of IBS is abdominal pain.

And that abdominal pain is due to visceral hypersensitivity or an overly sensitive gut and it's actually the action of these prebiotics in the large bowel that stretch the bowel wall and it's the sensitivity of the gut that causes the symptoms.

So we generally tend to reduce these FODMAPs to people's own tolerance in people with IBS to try and reduce the symptoms of it.

And what does FODMAPS stand for?

So FODMAPS is an acronym and it stands for fermentable.

Oligosaccharides now there's two types of oligosaccharides there's fructooligosaccharides which are found in wheat and inulin is a fructooligosaccharide and there's galactooligosaccharides galactooligosaccharides are the sugars that are found in pulses so chickpeas lentils peas and beans for example and as humans we don't have the digestive enzymes to be able to digest them so they're essentially the part of fiber that travels through to the gut so then we have, disaccharides and that's found generally in in in milk so it's lactose the sugar we have monosaccharides and the monosaccharide is fructose which is essentially a sugar that's found in fruit but interestingly that's tended to be added to ingredients as well as a sweetening compound more frequently, in processed foods as well.

And the other sugar that we look at is a sugar called polyols or sugar alcohols.

Now, these are artificial sweeteners that are added to foods.

They're called xylitol, sorbitol, mannitol and erythritol.

And you might well have seen, you know, if you have sugar-free mints for example sometimes on the packet it does say if too many consumed it may cause diarrhoea.

So those are the types of FODMAPs that we look at in respect to the diarrhoea.

Okay so if you've got someone coming to you with IBS symptoms I wonder if you could just very briefly tell us you know what IBS is and what symptoms someone would have and how common it is?

Yeah so IBS is really common so depending on the research that you look at you can find it between four and ten percent of the UK population so there's a lot of people have these symptoms, in respect to sort of when you're diagnosing IBS so GPs will normally look at sort of excluding other conditions because the symptoms are very similar.

So inflammatory bowel disease, for example, or celiac disease, depending on age, they may well do a fit test.

And if all of those results come back as normal, then there is a criteria called the Rome criteria, which is used to diagnose IBS.

So if you're presented with someone who's coming to you, who's had terrible problems with this visceral hypersensitivity, and they've got sort of, you know, they're complaining of abdominal distension and bloating and a variable bowel habit, what does the low FODMAP diet do?

Or how do you do it?

if I was coming to you as a patient, where would we start?

How long would it take?

Give us a brief sort of outline of what the program would be.

Okay, so what we would do as dieticians, there is a two-step process.

So when a patient comes to clinic, we obviously will assess the symptoms that they have.

We'll look at the diet because it's no good putting someone on a FODMAP diet if caffeine is the problem.

So we need to have a good understanding of what they're currently eating.

We would also screen people for eating disorders as well.

So sometimes with food exclusion diets, if somebody has done that by themselves, possibly people can get themselves into a bit of a.

And it tends to become a cycle and they can become very restricted in what they're eating.

And again, it wouldn't be appropriate to give a FODMAP diet in that situation.

So we'll do a full screening.

We'll just make sure that the diagnosis is likely IBS as well.

And then I like to look at the FODMAP diet as a three-stage process.

But before we get to the FODMAP diet, we have what we call a first-line approach.

So there is nice guidelines that give first-line advice.

And these are other foods that can affect IBS as well, because it's not all about FODMAPs.

Sometimes caffeine affects it.

You know, people don't tolerate alcohol very well with IBS.

So we look at those things first, and that's a much simpler approach.

If they've already done that, then we may well consider a FODMAP diet.

And it's a learning diet, the FODMAP diet.

So it's three stages.

The first stage is where we would reduce the majority of FODMAPs in somebody's diet.

Now, at that stage, we normally approach that for three weeks up to six or eight weeks.

And we generally tend to just do the reduction phase for as long as it takes to get those symptoms down to a good baseline level.

Now, it's not a cure for IBS and people will still have symptoms, but most people are happy and comfortable with the symptoms that they're having on a FODMAP diet if it works.

If they do get good reduction, then we move on to stage two.

And stage two is the reintroduction phase.

And this is the most important part of the diet.

This is where they then begin to learn about what foods are affecting them.

So we sort of reintroduce FODMAPs in groups.

So you're looking at your fructooligosaccharides, lactooligosaccharides, fructose, lactose and polyols.

And we introduce those in groups.

So it's not a long process.

The difficulty is that some foods have more than one in.

so we have to induce us separately.

We do three steps, three different amounts, so we're not going to put somebody back with symptoms that they were at the start, you know, but they will notice the difference if they're having a reaction to it.

Then, you know, it's really important that people monitor what they're doing through this so when they get to the end they can remember which FODMAPs they had an issue with.

Okay, so it's very labour intensive.

It is.

And the next step then is to just go on the modified diet.

And that, So the modified diet is really important because it frees people up.

So doing a restriction like this is quite a challenge for some people to achieve.

And we've got to sort of understand and respect that.

And it's also to make sure that those people with IBS are getting some prebiotics back in their diet that they can tolerate.

And that is really critical.

But, you know, it's complicated.

We tell them about sort of cooking.

We tell them to look at labels, to spot FODMAPs in the food that they're buying.

So it is quite an intensive process.

It's also probably worth remembering that FODMAP is quite an extreme way of managing IBS and that actually the vast majority of people with IBS can manage their symptoms with more minor changes to their diet.

And so, you know, presumably the patients that you're seeing, Julie, are sort of further along the line and have tried lots of things before they get to you and this is kind of one of the last resorts really for IBS going to this extreme of diet manipulation.

So yes I think you know there are stages to go through there are lots of other treatments for IBS that are effective as well patient choice has part of that but it is you know it is a step up from the general advice there is more research coming out as well in in dietitians approaching this from from a different angle and maybe looking at a modified FODMAP approach and this is where you know if people um you know are struggling to do the FODMAP diet you can just look at their diet history and take certain things out.

And that can be really helpful for people as well.

I agree with that because, you know, when I'm managing patients with IBS, you'll see them too in general practice.

I quite often would get patients to do one month off cow's dairy, for example, or one month off gluten.

Those are, you know, biggies in terms of irritants for the gut.

And it's relatively easy to take one thing like that out of the diet for a four-week period and see whether that makes a difference.

And then you can obviously go straight back to it if it makes no difference after that time.

Yeah, I mean, sometimes just doing a simple diet history or just getting them to keep a diet sheet for a few days, you can sometimes see some standout things.

So, for example, high intake of carbonated drinks, even if they're, you know, diet drinks or in fact, as you were saying, Julie, the sorbitol or the xylitol in these diet products can really cause a lot of gas.

I know that sort of certain types of chewing gum or sugar-free sweets of people having, you know, more than one or two can really cause a lot of gas in people.

So sometimes you can just, you know, look at the obvious things first.

I agree because I think, again, you were alluding to this, Julie.

My concern as a GP is that people start on these extreme exclusion diets.

They're not quite sure if they're helping or not.

And then they just stay on them.

So they're stopping, you know, dairy.

They're stopping gluten.

They're now stopping FODMAPs.

And then they don't really know where they are.

And they just kind of stay on these very restricted diets.

And obviously, over a longer period of time, that can cause various nutritional deficiencies, which can have big impacts on your health.

I mean, how do you find, what are the deficiencies that can happen because of restricted diets, Julie?

So calcium is a big one, you know, if patients are excluding all dairy.

I mean, in essence, you know, it's lactose that's the issue.

So lactose-free milk is cow's milk.

It's got the same level of calcium in it, but patients go on alternative dairy milks, which sometimes are not always fortified with calcium.

Julie, I'm going to interrupt you there because I have to say I disagree with this lactose intolerance business, because I've done a lot of research into cow's dairy intolerances and I do think that it's down to the casein A1 protein and not the lactose.

Now, it is lactose intolerance in certain groups of patients.

So, for example, our Asian populations do get lactose intolerance.

genetically.

And they're the group that do really struggle with cow's dairy from a lactose perspective.

But in the UK, our main issue is casein A1.

And casein A1 is in the cow's dairy in the UK.

And casein A1, when it's broken down in the gut, forms a toxic metabolite.

And that's what drives low-grade inflammation in the gut.

And I find that most people who say they're intolerant of cow's dairy can tolerate goat's dairy without any problems.

So that I think solves the calcium issue.

And I've actually changed a lot of my patients and a lot of my family and myself to goat's dairy with great success and managed gut issues that way, which has, you know, hugely successful for me and my family and for many of my patients.

But it gives me the peace of mind because goat's dairy obviously gives you the same nutrition that cow's dairy does, but without that inflammatory component.

Yeah i mean i guess a lot of the plant-based milks have added for are fortified with calcium and various other minerals and vitamins now is that right.

You remember their calcium carbonate supplements and in within the plant dairy and calcium carbonate is derived from rocks and calcium carbonate is the one that has actually been associated with cardiac issues so it's not it's not a great supplement on its own um it's better to get more natural forms of calcium through through dairy if you can then then have the supplemented versions.

So yeah i mean there is um you know some people who have um possibly a different reaction and i know that there was um at one point um a different type of milk that was available in the uk um that had a had the different protein in it um i think in respect to that it's it's we've got to be really careful as well that we sort of um don't miss milk allergies in respect to this um and it can be really quite tricky um to get that i mean i don't know necessarily about the evidence um you know you mentioned about the calcium carbonate side of things i'll certainly have a look into that after today but it's all very interesting and I think food intolerance is a really complex area, alongside the food allergy side of things as well.

And I think it's important to have a look at how scientists know what we know about flatulence and farts.

And actually, it's an area that hasn't been kind of been dismissed, I think, in terms of what the gastroenterologists do.

But if you look at actually what people do and how they find out about farts, it's quite kind of interesting.

So there's a couple of studies in the 1980s and 1990s where they take healthy people actually put rectal tubes into the anus these I don't know how they got these volunteers or whether they paid them or how they consented it but then they sort of you know analyze or you know the volume of gas and the contents of the gas by getting them to wear these tubes for several days and actually analyzing the gas bags and how much they produce the volumes they produce, and then seeing what they produce with different types of food.

So it's a pretty kind of invasive and sort of not very scientific way of doing it.

So it's really interesting.

They're now looking at these smart capsules.

So there was a guy...

University, which is where they did the whole low FODMAP diet, where that comes from.

So it's obviously a big center for the examination and the scientific investigation of the gut intestinal gas production.

So you swallow these capsules, they've got electronic sensors, and they actually in real time detect the volume of gas, the type of gas and the pH and also the temperature as it goes along and you can actually track what's happening.

So as we know, there's a different ecosystem in different parts of your gut.

So you've got different combinations of microbes in the mouth and the stomach and the ileum and the colon, and actually all these bacteria producing different amounts and types of gas.

So they're actually finding out a lot more.

His plan is to develop a kind of a fart database.

So they're actually looking at what people produce in different areas.

And then what they're starting to do now is do studies on humans where they're giving them different types of diet and actually assessing how quickly the gas signature changes.

And they're trying to sort of track that with various disease and lifestyle changes as well.

So it's kind of a voyage of discovery.

And I love this idea that the simple fart is now being, you know, mined as this sort of knowledge base that if we can get as much information as possible out of it we're going to find out lots of interesting things about what's actually happening in real time in the gut and they're also looking at taking biopsies as well along different parts of the gut and microbiome samples because we all know that the stool analysis that is used for most microbiome analysis is just you know is not that useful about what's happening further up the gut so hopefully we will be finding out a lot more.

Yeah, that's great.

And thank goodness they've come up with an alternative to those tubes coming out of your back.

Well, I know it does sound ridiculous.

Yeah, they also do CT scans.

So they analyze, you know, the actual volume and distribution of gas.

But again, it's pretty basic.

So there is a lot of excitement about these new smart capsules.

But yeah, so just moving on to some animal stuff before we go back to the medical stuff and human stuff.

I just wanted to tell you about both about you know there's people in different areas of science looking into flatulence and there are a couple of animal scientists uh nick caruso and danny ria vatti rabbiati rabbiati i'm not sure how to pronounce that so they had a best-selling book in the new york times bestseller list in 2018 called does it fart and these are two scientists that sort of started looking into the farting habits of various animals so just a quick yes no ladies yes do these animals fart or not, okay starting with julie dogs oh definitely yeah she know dogs yeah.

Because i i remember my dog farting very loudly and all of our.

Okay yes causing a lot but you know and also we have to have a dog because we that's if we do do a smelly fart you can just always blame the dog so dogs are absolutely tick there.

Dinosaurs, did they fart?

Yes.

What do you think, Julia?

Yes, no.

Ooh.

Yes.

Sheena, yes.

Yes.

Just a guess.

Yes or no.

Yes, I guess.

Yeah, you're right.

Octopus.

Oh, I don't know.

Apparently not.

Apparently not.

Millipedes?

No.

No.

Yes, they do.

Really?

How do you measure a fork for a millipede?

What about, well, I'll tell you in a moment.

Herrings?

Herrings?

No, I'll go with those.

Apparently they do.

They use it as a way of communicating.

Spiders?

Well, if millipedes can, spiders can, presumably.

Well, you know, I would say not.

Apparently they're not sure.

They don't think so.

But someone is doing some research into this area.

And I love the fact that these guys are going around looking at these animals.

So the most smelly animals, seals and sea lions, they've got very foul smelling farts, apparently, because they have lots of fish and shellfish, which are very high in sulphur.

So their gut microbes kind of produce this hydrogen disulfide, which is that kind of rotten egg smell.

Then we have snakes that use farts as scare tactics.

So there is something called the eastern hognose snake and the Sonoran coral snake.

Have you got that, Julie?

You remember those names?

They do this thing called cloacal popping.

So they suck air in and out of the cloaca, which is a kind of their version of the anus.

And they make this popping noise, which apparently frightens predators away.

But this is my favourite, OK?

The beaded lacewing larvae, silent but deadly farts.

Okay these larvae produce farts containing a chemical called alamone and this chemical is capable of paralyzing termites so apparently a single fart can immobilize an army of termites for up to three hours some of them die but not all of them but it gives these beaded lacewing larvae time to devour their much larger prey so it made me think of this kind of silent but deadly it can actually be that so and then finally when we're talking about farts and animals we've got to think about cows there's this kind of you know methane global warming situation where we've got one billion cows globally they ruminate in these four chambers and apparently they extract lots of nutrients but produce a larger amount of gas um so apparently one kilogram of methane produced by.

In the atmosphere than one kg of carbon dioxide.

So it's this idea of cows contributing to climate change.

So it's a very important area, thinking about this.

What we haven't talked about are the actual microbes that do all of this.

Okay.

Yeah, go for it, Sheena.

Tell us a bit more about that.

Well, what I was going to say is that there are obviously loads of microbes in our gut that will produce gases.

And there are certain ones that produce the methanes.

There are certain ones that like these are often called methanobacter or, you know, something like that.

And there are microbes that produce the sulfides, which are the really super smelly ones.

So yeah, there's lots of different types of microorganisms in there.

And there's some microorganisms that are slightly better at suppressing the gases like the ones that we often see in fermented foods like lactobacilli and bifidobacteria they're they're slightly better at sort of suppressing those gas productions um so that's that's quite interesting and because we've all got that individual makeup in our gut you know we we will find that as you say everybody will have their unique smell and will will produce a certain type of of gas and and that will vary day to day depending on what you eat you know and and um yeah it's very very interesting um and and you know what's what's good and what's healthy and what's not so healthy it's it's really tricky to know isn't it because there's such a wide variety even within the normal population in terms of you know how much we fart and how smelly our farts are and whether, you know, the types of smells that people produce.

So, yeah, it is interesting.

And within families, we all know that you will walk into a room and you will know I remember as a kid, I know my big brother had been in that room because he had a very distinct, you know, perfume in his farts.

So people do have this, you know, obviously it depends on what you eat, but, you know, I guess your microbiome composition as well.

There's a really good paper, which I'll put in the show notes by Ian Rowlands and Glenn Gibson.

I think they're both from Reading.

But it really goes into the incredible intricacies of the chemistry of the microbial fermentation and the production of these flatulent farts.

And they were sort of saying that many of the microbes can make gas, but not all of them.

And Sheena, you were saying apparently lactobacillus and bifidobacteria, they don't produce gas.

So although most of them do, and often, although they're producing these gases, often those microbes are, they're not just coming out the bottom end in their hosts.

They're actually being used, these gases.

They can be a valuable source as part of a sort of metabolism.

So they're reused as, you know, part of the microbial metabolism.

So it's kind of very, very intricate and complex.

And if anyone wants to know more, I really, they've got a whole section on the production of gas there, which, yeah, is really worth having a look at.

You know, obviously, as a GP, I'm trying to get patients to have high fibre diets all the time.

And you were talking before about FODMAPs and everything and, you know, all those foods that we want people to eat, that big, wide variety of plants in their diet, eating the rainbow.

But these fibrous plants will make you fart more.

And that is a bit of a stumbling block for a lot of people because when they start changing their diet, they notice more flatulence and it can really put people off.

So, Julie, what do you tell patients in these situations about, you know, what to expect and how to get past that increased flatulence and everything at the start?

So I think in respect to sort of if people have a low-fibre diet, you know, there was some...

Studies that were published um in june this year so the national diet and nutrition survey um you know looked into um uk's average diet and we know that people um were getting on average 16 grams of fiber a day now the health advice is to get 30 grams a day and actually as a nation we're eating less yeah over time so that's probably before 2020 was um about 19 grams a day so we need we do need to be eating more now when we're advising about about fibers we um generally advise people to sort of slowly build up their intake um we know that if people have a you know a huge amount all at once it you know they've got needs a little bit of time to adjust to a new um level of fiber and if if you introduce that too quickly people generally tend to get a lot of gas and bloating so we do it we do it slowly essentially um but and and you know and there's another aspect to this i think as well the more variety we get in our diet the less um.

Impact one particular type of food has so you know having a wide variety of these things can can can be helpful as well.

So what you're saying if someone's just picking one food like going right okay i'm going to increase my fiber i'm going to have two cabbages a day.

Yeah that.

Is not the way to go it's much better to have sort of lower amounts of lots of different types of plants so it's small amounts of.

Yeah absolutely fruits.

Vegetables and legumes and, And go small and steady, build it up.

And also don't worry about farting a bit.

There's no problem with it.

It will settle down.

And, you know, just there may be one or two things that are a bit of an issue and you can reduce those.

But would it be true to say often does settle down?

Yeah, it does over time.

But again, you know, there's some, like you said, there's some aspects of this really.

You know, I think sort of farting is really stigmatized, you know, as a society.

and actually it's it's part of having a healthy gut.

High fiber and eaters are generally going to a bit more than lower fiber eaters aren't they yeah um so that's that isn't anything to be concerned about or worried about or even embarrassed about because because that is a natural natural thing and and in fact you know hopefully this podcast will reassure you that it's entirely normal to fart more when you have a high fiber diet but but actually the high fiber diet is doing your gut a lot of good and your microbes a lot of good and so try and stick with it.

And I think as well you know there are some some tips um you know that can help um if you're sort of um using public toilets for example and you are a little bit concerned so um you know you can use something called a courtesy flush.

Right when you're.

In a cubicle so you flush the toilet so you can hear more the sound of the toilet rather than the sound of the fat the other thing is wait for somebody to use the hand dryer for example.

Okay so you're saying for those in the toilet who are absolutely dying to fart and it's causing distress and they're feeling bloated but they're just about to and then two people come in and they're just thinking what can I do you're saying yeah flush the loom make a noise turn the on and go for it okay that's that i don't is that just a ladies thing or what happens in the men's lose do you think they don't care um.

So i know we had this conversation um prior to the podcast um and and i don't actually recall um hearing a fart in a lady's toilet but i did ask my partner so my.

Husband said.

That he does hear them.

When men are in the cubicles and they don't care do though they go all Celia Imri they're proud out and proud I'm gonna you know she's our hero that's.

A case study of one isn't it so perhaps we need some more um data on that.

Does sound like we're the ones doesn't it.

So yeah I do understand you know you're kind of not quite sure whether you're going to have an odorless fart or whether it's going to be a bit smelly I can see why some people do find it a bit embarrassing there's a whole whole etiquette about farting but the more we talk about it and the more we let it out it's just you know it's it's got to be better for everyone that these normal physiological processes are you know are out there and normalized i.

Think as well with the order in in toilets as well there are products that you can buy that can mask it.

What are those and do you ever advise those for patients?

So we wouldn't advise one specific product, but there are a range of toilet sprays that you can buy and products that reduce that order.

I did have a look at a couple of papers on charcoal underwear and charcoal cushions because I thought that is ridiculous.

There's no way that's going to work.

But apparently it does absorb lots of the sulfur type gases.

And in some, they actually, there was one study where they fed these healthy participants, you know, cabbage and all sorts of, you know, stuff that really causes smelly farts.

And there was one of the scientists actually did the smell test.

I don't want to go into the details of this.

I can't quite.

I'll put the paper at the end.

But actually, and then they also did a sort of scientific test on the concentrations of gases, sulphur-containing gases.

Again, this was using the rectal tubes that we talked about earlier.

And they did find that I think it was up to 80 or 90% reduction in the emission of these very smelly gases if you're wearing charcoal underpants.

But I just can't quite imagine what these underpants look like or charcoal cushions as well.

or whether it was actually the fact that they're within a kind of pair of plastic pants.

So anyway, if anyone's listening and they know about these, or indeed if they've got a pair of these in their underwear drawer, then please do contact us.

And maybe we can move on to our Christmas list now because that's definitely going to be on the Christmas list for many people.

So let's talk about fart-related books, gifts, gizmos for Christmas because we're at the Christmas season.

Julie, have you got anything for us to put in our stockings?

Yeah, so there's a really interesting book by an author called Stefan Gates called Fartology.

Okay.

I.e.

the science of farts.

So, yeah, that's a really interesting read.

Anything that struck you out of that book?

Yeah, so there was a doctor where one of a surgical nurse asked them, you know, whether it was okay to discreetly fart during surgery.

Okay, in terms of spreading disease?

Yeah, in terms of microbes, okay.

Yeah, yeah, yeah.

So it's a sterile environment, isn't it?

You know, and people are scrubbed up and everything.

And was it okay?

And this doctor didn't know the answer to that question.

So he decided he'd work alongside a microbiologist and got one of his colleagues to fart five centimetres away from a Petri dish.

Clothed and unclothed and the results of that and again you know we're looking at a case study of one here um the result of that was that um where it was clothed there was there was no growth on that on that petri dish at all um where it wasn't clothed there was a little bit of growth of natural sort of microbiome that we find in our skin and and in our guts that wasn't necessarily harmful so that was really interesting.

So any surgeons or surgical nurses or theatre staff listening it's fine to have a sneaky fart in the theatre I think I think yeah you know anyway that sounds like a great book there's a couple of great kids books there's one called does it uh no one likes a fart by Zoe Foster Blake which is absolutely gorgeous for three to five year olds about this little fart that's got no friends because it's smelly and it's really nice and and then there's Stephen Mangum who you may know from the green wing or he was the voice of postman pat so he's co-authored a book with his uh i think it's his sister anita mangan she's an illustrator the fart that changed the world which is a great kids book uh came out 2022 and that's a bestseller and really really good fun um and then i just thought uh i i knew a doctor once who actually could make their car fart sheena do you know anything about that yeah.

I do have a farping car, It's very cool.

It was a big selling point for the kids when we got that car.

Okay, tell us what car and what the hell are you talking about?

I've got a Tesla.

And basically, I can, there's a little icon, only when I'm parked, by the way, Tesla doesn't allow you to do this when you're traveling.

But essentially, there's lots of little games and things you can play with in the Tesla.

But you can make everybody's seat fart on the in the tesla so you can move the fart around the the car and make everybody fart in the car which has caused you know lots of lots of hilarity for my kids over the years and yes it's very enjoyable if you have somebody um new in your car who doesn't know that this exists.

That is like that's a very very very expensive whoopee cushion isn't.

It i mean you know i don't.

Know i don't know if anyone's gonna get that for the christmas gift but you know if you've got a lot of money and you want to bring a smile to your children, then maybe you should think about buying one of these Teslas that Sheena's got.

So, I suppose let's just wrap up with a couple of takeaways from each of us on, you know, what we've learned or what we think or what we'd like the message to be to anyone listening.

Julia, let's start with you.

Any actionable points for people who are concerned about flatulence over the Christmas period?

So, I would say, you know, own it we know that this is good for your gut microbiome we know it's a normal part of of our physiology essentially and so i mean we over the christmas period and it just to talk about sort of that christmas meal so in in in the thompson household we generally start off with artichoke soup now artichoke has a large amount of inulin in it um so you know it is going to produce some effects, And, you know, the normal Christmas lunch, so we all know about Brussels sprouts, for example.

You know, people might have cauliflower on there.

And again, you know, it's generally a higher fat meal.

People generally have alcohol alongside that.

So it does produce gas.

And that might be a good excuse maybe not to visit their relatives on Boxing Day.

Can you tell us a little bit before we go just about Guts UK Charity?

Good UK Charity is the charity for the digestive system.

We are UK-wide.

As a charity, we've got three charitable objectives.

One of them is to provide information for people who have a digestive condition or have symptoms.

So we do have information on our website about wind and bloating as well as a separate information sheet.

We raise awareness of digestive health.

So this, podcast is really useful for us to to get the word out there that farting is actually quite normal and the other aspects of guts uk is that we fundraise for research into the digestive system.

What about sheena what are your kind of take homes or your messages to anyone listening.

Well, I think for a start, my husband's going to be very glad about this episode because I'm always telling him off for farting.

I think because I suppose I am quite reserved when it comes to farting.

If I fart, I probably prefer to do it discreetly, whereas I get a bit annoyed when my kids or my husband fart really loudly at the dinner table.

But he's probably going to get his own back now and tell me that it's entirely natural and he's and he's allowed to fart as loudly as he wants now so so I'm gonna pay the price for this podcast but but essentially what would I like to tell people yes it is natural uh yes and don't don't worry about farting more when you're when you're upping your fiber and when you're having your fibrous Christmas dinner with your Christmas bubbles as well it it's all okay and yes if you've got a dog, still blame the dog.

Yeah, good idea, good idea.

Yeah, so, you know, finally, just the kind of, you know, the amazing ecology within that you've got these microbes that are...

You know, having conversations, they're producing a bit of gas.

And I just love this idea that, you know, most of the gas we produce is produced by these, you know, wonderful living organisms within us who do so much good.

So the fact that they're producing gas means it's working.

They're producing short-chain fatty acids, which have incredible beneficial effects on pretty well every aspect of our health and physiology.

And as Julie said, it's a sign of a working gut, which is why when you wake up from, you know, surgery, first thing the nurse will ask you is, you know, is your bowel working?

Have you passed wind?

And there's kind of great cheers if you've started passing wind because it means you're on your way to recovery.

So it's a sign of a healthy bowel.

So thank you, Julie Thomas, for your expertise.

Thank you, Sheena, for your input and your story about your Tesla, which is hilarious.

And thank you for listening.

I hope that you found this interesting.

We'll leave loads of references in the show notes if you want to find out more about the science of farting.

And have a wonderful Christmas, and it's goodbye from us.

What was that?

Oh, God, I'm really sorry.

That was me.

I always own up.

I'm really sorry.

Don't worry.

Chris can edit that out, can't you, Chris?

Chris?

Thank you so much for listening to this episode of Microbiomedics Podcast.

We really hope you enjoy the content and we welcome your feedback.

We'd love to hear any suggestions you might have for microbiome topics that you'd like us to cover and we also appreciate listeners' questions and we'll endeavour to answer them in the next podcast.