Dr Rupy: Could your gut be leaky? And is leaky gut a real phenomena? It's world gut health day and I want to dive into this topic. I think you're going to find it super interesting.
Dr Rupy: Hey, it's Dr Rupy. I'm going to be doing a solo episode today because it's World Gut Health Day and look, gut health is very trendy right now. It has been for the last five years. If you look at Google trends, it's just going up and up and up. And you're and I'm seeing fizzy prebiotic drinks, probiotic gummies, reset plans, powders, all promising to fix your gut. But in the middle of all this noise, people I speak to are still super confused about how to look after their gut. And what I want to do is just reframe everything, bring it back to basics. And I want to do a bit of a dive through the lens of leaky gut because I think if I can explain leaky gut, what it is, whether it's a real phenomena, and then also even using the terminology of leaky gut, explain how you can support gut health with just the basics. No supplements, no probiotics, no expensive plans. Hopefully we can create not only confidence in one's ability to impact their gut health, but also confidence in the ability to understand these scary sounding terms, what the evidence is actually showing us. And hopefully you can share this with other people as well that you might be having conversations with where the term leaky gut gets thrown around because I'm definitely hearing about it in wellness circles, online and on YouTube as well. So this podcast episode is going to be all about leaky gut, whether it's a real phenomena and what you need to know about it. As a reminder, all of our podcasts are sponsored by Exhale because I am a chief science officer for Exhale. I'm super passionate about this company. If you're curious to try Exhale, you can get a free bag by just heading to Exhale and using the code RUPY241. They'll send you a free trial bag. Honestly, it's delicious. It's roasted for polyphenols. It's organic, it's completely traceable. I know Kirsty and Al personally, we've been working for like four years before I became their chief science officer and I'm a passionate coffee drinker myself. It also has gut health benefits because it's a prebiotic. And if you're interested in gut health more widely, definitely check out the Doctor's Kitchen app. We've got a new gut health goal there. And one of my favourite features is actually just typing in a random ingredient. So for example, if you want to use up some tofu or you've got chicken that's left over and you don't know what to do with it, type that ingredient into the search bar and we're going to give you tons of recipes to provide inspiration and variety to keep you healthy and keep your guts on track as well. We also have a new feature, brand new feature that we are tentatively launching. So if you download the app and you start an account, you'll be able to speak to virtual Dr Rupy. Yes, virtual Dr Rupy, you heard me right. We have essentially created a clone of myself. We have trained it using our podcast data and articles and all the information, all the research that we use for the app as well. It can suggest recipes, you can ask it for swaps. If you're looking at a recipe, you're like, I wonder if I can use courgette instead of aubergine. Virtual Dr Rupy will be able to tell you how and whether that's possible. It's super, super scary for me, but also really, really useful for lots of our users. We did a beta test round and people went absolutely wild for it. So go and download the app, try having a conversation with virtual Dr Rupy and let me know how you got on with it. I'm really, really intrigued. On to the podcast.
Dr Rupy: When you Google gut health, it's almost inevitable that you're going to come across this scary sounding term called leaky gut. Now, when I came across this initially, I remember thinking to myself, what's a leaky gut? That doesn't sound good. Who wants a leaky gut? Do I have a leaky gut? So for World Gut Health Day, I want to do a full podcast episode cutting through this supplement marketing and scary sounding term to talk about why your gut might need support even if you feel totally fine, what leaky gut actually means and whether it has any research around it, and whether supplements like probiotics for leaky gut are a complete waste of money or not. I'm also going to talk through my favourite foods that are going to keep your gut ultimately healthy. I'm also going to be bringing in insights from some brilliant experts that we've had on the Doctor's Kitchen podcast before, from microbiome researchers to colorectal surgeons. So you get a plethora of different opinions on this subject. If gut health has ever felt overwhelming or over complicated or just not that relevant to you, then hopefully I'm going to be able to clear up a whole bunch of terminology and get you more confident about your gut health. Okay, so the first thing is, gut health is still often framed as something you only deal with when something goes wrong. But we all need to understand that the gut does far more than just digest food. It's a living interactive space where the food you eat, the microbes that live inside of you and your biology all talk to each other. It's part of the foundation for your long-term health. And you've probably heard me say this before if you're a regular listener, but your gut is home to trillions of microbes, including bacteria, but also viruses, fungi, archaea, and they're not just passengers, these are active players in our health. They train your immune system, which is important from everything from dealing with common colds to autoimmune conditions and even detecting and dealing with cancer. They ferment fibrous foods that you consume into short chain fatty acids like butyrate, and butyrate is a particular type of fatty acid that fuels the cells that line your colon. I'm going to talk about this a little bit later as well. And this is very important for reducing inflammation in your digestive tract. Your microbes also support blood sugar regulation and appetite control. By feeding your microbes the right types of foods, you will naturally reduce cravings and it will help with weight management. Your microbes will signal through hormones and other metabolites that they create as well. And it can even influence your brain and mood via something called the gut brain axis. This is a two-way communication line that works through nerves like the vagus nerve, which is this long winding nerve all the way from your brain down to your gut and molecules like tryptophan as well. Okay, when your gut is struggling, it doesn't always shout at you. It sometimes whispers with subtle changes like ongoing fatigue, low energy, skin issues like eczema or acne, feeling anxious or flat without a clear cause, or brain fog or poor memory, hormonal imbalances. It doesn't mean that all of these symptoms are always caused by poor gut health. These are multifactorial. I mean, stress, environment, even the interplay with our genes all play a part. But the gut is often a big and overlooked contributor and it's often where I look first as a medical doctor who takes a holistic approach to wellbeing. And once you understand just how connected the gut is to everything else, it's no surprise people start wondering about all the other things that could go wrong. And one phrase that always comes up is leaky gut. You've probably heard it thrown around wellness circles, sometimes in ways that feel a bit vague or alarmist. So let's talk about whether your gut can really be leaky. When people talk about a leaky gut, what they're usually referring to is something called increased intestinal permeability or hyperpermeability. It sounds a bit terrifying, but stick with me because it's a lot more nuanced than that. So let's go back to basics for a second because one of the weirdest but most important things to get your head around with your gut is that your gut or the contents of your gut are still technically outside of your body. So think about your gut, it's a long hollow tube starting from your mouth all the way down to your anus, around 9 metres long. Now the analogy I like to use when trying to explain this unintuitive concept of what's in the gut still being outside of your body is using a ring doughnut. Okay, so picture a classic ring doughnut with a hole in the middle. If you poke your finger through the hole in the middle, your finger hasn't gone into the doughnut, it's just sitting in that open space. Remember, we're talking about a Krispy Kreme style doughnut with a hole in the middle, not a jammy doughnut. You haven't touched the doughy part, the actual substance of the doughnut, you're just putting your finger into dead space. Now, imagine that this doughnut, the Krispy Kreme doughnut, gets stretched out, like really stretched out, and it's this 9 metre long tube. That's your gut. And so whatever is inside that ring doughnut, it's still outside of the doughnut. It's not in your body. This is where all the free space is still technically not inside of you. It's just moving through this tunnel. So whenever you put food into your gut, it is still treated like a foreigner by your body. It's still outside of your body. It only enters your body when it breaches the walls of the gut or something called the gut barrier. We also use gut lining interchangeably and this is because this is the lining of cells on which the other side of your blood vessels. Now, your blood is how the nutrients and other components of digestion can be utilized and transported around your body to fuel your cells and all the other things that you need food to do. So whenever you hear the term leaky gut, I want you to remember a few things. The number one thing is that your gut should be leaky. Your gut needs to have some permeability because otherwise food would just be going through this tube out the other end. You wouldn't be able to absorb anything from the food that you're consuming. So to be more verbally accurate, it should be permeable to nutrients and some microbes, but not so leaky or hyperpermeable that it triggers your immune system, which raises your inflammation level and can lead to issues. Now for ease, I'm going to for the rest of the pod use the inaccurate term of leaky gut because I feel that this is something that people utilize themselves and it kind of sounds intuitive to them. But as long as you recognize that I'm technically referring to the accurate term or the research term of intestinal hyperpermeability. There's no controversy around this leaky gut concept and the relationship between inflammatory bowel disease, coeliac disease and other gastrointestinal disorders. We do know that hyperpermeability does occur in these disease states. However, the relationship between leaky gut and autoimmune conditions, depression and other mood disorders, type two diabetes, multiple sclerosis, dementia, etc, etc. This is still hotly debated. So there is certainly an acceptance that gut permeability can occur, but whether this is occurring and is it even way causal or related, causally related to some of these other conditions, that is where the big question marks are still there. The second thing I want you to remember whenever you hear about this term leaky gut is that your gut barrier is really robust. This gut barrier is often described as being one cell thick. You've just got this lining of one cell thick, which makes it sound really fragile, but it's so far from that because actually your gut defenses, your gut barrier is a multi-layered defense system built to carefully control what gets in and what stays out. So think about a piece of food that you've just ingested, traveling from your mouth down the esophagus, entering the stomach and so forth. It's first going to encounter chemical defenses. So when that food goes through the esophagus into the into the stomach, you're going to get bile, gastric acids thrown at it, enzymes that neutralize anything that finds its way into this area. And the bacteria that live in your gut along the way are also going to secrete antimicrobial peptides to make sure certain microbes are kept in check and don't over colonize the gut environment. So they don't overgrow and take over, leading to an imbalance and sometimes this imbalance is referred to as dysbiosis. So the gut isn't a friendly place to anyone that's coming down. There's a lot that's going to be thrown at it. So that's the chemical defenses. Then you've got a mucus layer. It's sort of like a safety map. You've got a layer of water and mucus which also secrete immune compliances like immunoglobulins, like such as IgA. And these again prevent invasive bacteria from latching onto cells and hanging around too long. There's no loitering allowed in the gut. You can't loiter there. You might think of mucus as like, you know, an inert substance that's a bit annoying when you get a cold. It is so far from an inert substance. It has got a strong immune function, which is why you find it in sensitive areas such as the nasal passages and your lungs, for example. It's going to be having this immune role as it's got immunoglobulins built into it. And then you've got epithelial cells. This is sort of like a smart gate. After all of this, you've got the chemical defenses, you've got mucus, again with all these different antimicrobial properties. If you make it to the gut lining, which are termed epithelial cells, these are glued together by junctions and this is referred to as the junctional complex. And their role might just be to transport the content from the gut into the bloodstream. But you don't want to mess with these guys either. They can secrete chloride, again, more peptides that have antimicrobial properties. They add another layer to the gut defense. Now, I used to think that these junctional compliances, also known as tight junctions, between the gut lining cells, which are one cell thick, I used to think that these were responsible for leakiness, but there's actually three sets of these different junctions. There is the tight junction, an adherence junction, a desmosome, and together they comprise the junctional complex and provide multiple checkpoints along the way. So it's a lot more than just a simple breach in the gut lining that is easy to achieve. The way I think about it is sort of like airport security. You don't just have the body scanner and then just get on the plane. You've got someone at the start of the airport security process checking your tickets, and then you check the passport, and then you go through bag check, and then again you've got someone checking your ticket again, and then right before you board the plane, again you've got a passport check and a ticket check. There's all these different checks and balances before you get into the plane. And it's sort of like that in the gut. And if you remind yourself about what I was talking about earlier about what's in the gut is still technically outside of your body, it is no wonder that there are so many checks and balances that food needs to go through before it's allowed to go anywhere near your bloodstream because if we were to consume a dangerous microbe via breathing it in, eating it, drinking it, it could access our bloodstream, multiply rapidly, creating a generalized infection that we call sepsis. And this is why a huge majority of your immune cells are actually located in your gut. So hopefully this is all making a lot more sense to you right now. Multiple checks and balances, lots of defenses, your gut barrier is more than just this cell lining that has the bloodstream on the other side. You've got multiple checks and balances all along the way. I want to read a quote from my latest book, Healthy High Protein, because I think it articulates the point that I'm making about with regards to your gut. I think it's important to reiterate here that your gut is very resilient. And just like a rugged pair of denim jeans, your gut barrier is designed to be worn. When people hear the term leaky gut, it gives the false impression that our digestive tracts are easily damaged and weathered. It's quite the opposite. This robust perimeter is constantly exposed to microbes, inflammatory proteins, debris, toxins, noxious chemicals, and just like a well-seasoned fishing boat with a hardy skipper, you can throw a lot at your gut. In fact, it's lined with stem cells. These are specialized cells that can regenerate into multiple types of cells very quickly. These can replenish damaged ones in need of repair. So this is all giving you the correct idea that your gut is much more than just a single lining of cells. It is super robust and you should really think about your gut as like this incredible piece of machinery that has evolved over thousands of or millions of years to protect us from the outside world. It's not something that is easily perturbed. So, if our gut is so robust, how do unwanted things actually sneak through? How do we get this leakiness? Well, people often imagine that if your gut is leaky, food proteins and toxins and and even bacteria squeeze through these junctions in between your epithelial cells, your gut lining, your your gut cells. They're also called colonocytes. But that's actually not quite right. There are two main ways to cross the gut barrier into the bloodstream. There's the paracellular route, which is between the cells, or through the actual gut cells themselves. This is called transcellular. Most people talk about the paracellular route. So that's the space in between the cells lining your gut and are normally sealed by these junctional complexes, these tight junctions, etc. If these seals loosen, it can allow small molecules like fragments of food proteins and environmental toxins or bacterial byproducts to pass into the bloodstream. But whole bacteria and large toxins are usually too big to pass through those gaps, even when the barrier is compromised. So the more surprising route is this transcellular pathway, which is actually going through the gut cells themselves. What happens is that these gut cells actively take in and transport certain substances across. It's sort of like the gut cells wrapping bacteria in a bubble on the interior side of the gut and then taking them through the cell, dragging them through and then expelling them on the other side, which is where your bloodstream is. So even if the gut wall isn't totally broken down and the spaces between the cells are fine, bacteria and other products can still sneak through the transcellular pathway, especially when there's inflammation, stress or immune system issues going on. So this means even if your gut barrier looks intact, inflammation or immune dysfunction can still allow these troublemakers to go through. And that's where this idea of leaky gut as holes in the wall and all that kind of stuff is overly simplistic. And this brings me on to another point about leaky gut and how it is super difficult to measure. This is probably the biggest bugbear of researchers and clinicians with the whole concept of leaky gut. It's because there is no gold standard clinical test that can say for sure whether a gut is leaky or not. Now, there are a few experimental tools used in research, but it's not something that can be diagnosed with a quick blood test or a stool sample. A lot of people are surprised by that, especially with how many gut health tests are being sold online right now. You would assume that some of these actually have some validity. One of the tests or one of the tools that we do use in clinical practice is something called the lactulose mannitol test. You basically drink a solution of these special sugar molecules. Some of these sugar molecules are small, some of them are larger. And the idea is that if your gut lining is healthy, only the small sugar will get absorbed into your bloodstream and shows up in your pee. There's a higher ratio of small to large molecules. It sort of makes sense. But if the gut is leaky, then the larger ones also get through because it's more permeable. And this skews the ratio of small to large molecules that ends up in the pee, which we can interpret to mean a leaky gut. However, this test is really, really unreliable. Your diet, how much water you've drunk, even how the test is done can all affect the results. For example, some of the sugars used in the tests can sneak into your system from foods or products that you've already eaten, which can impact the results. And to make things even more complicated, we don't even have clear reference ranges for what counts as normal versus leaky. So these tests have to be interpreted really, really carefully, and they're usually only done by specialists who are looking at lots of other markers as well as a decent history of your clinical symptoms before making a diagnosis of anything that could be gut related. Researchers on the other hand have newer tools looking at endoscopy, so these are telescopes and high-tech cameras that we put into the gut. Uh there are also sensors that can detect real-time changes in the gut barrier when you're exposed to certain foods. And that gives us a lot more evidence that gut leakiness may happen in specific situations, which for example is why we know this does happen with certain people with irritable bowel syndrome or even uh inflammatory bowel disease. But again, that's a research tool. It's not something that most of us have access to as well. Now, there are some other ones, simpler lab markers that researchers are exploring to give clues about whether your gut barrier might be compromised. And some promising ones, and I do want to underline promising, but not, you know, solid, are LPS, also known as lipopolysaccharide. So this is a uh toxin that comes from the outer wall of certain bacteria and it should not be in your bloodstream. So you can think of it like the coat on uh your bacteria on certain types of bacteria and they leave this coat lying around and then we can measure that in the bloodstream. A high LPS in the blood can suggest that the gut wall isn't doing its job properly. And there's a couple of others that again, you may or may not have heard of. It's not particularly important because I don't think they're particularly reliable. There's IFABP, which is intestinal fatty acid binding protein, bit of a mouthful, I know. It's a protein that is released into the blood when the cells lining your gut gets damaged. And then another big one that comes up is zonulin and claudins. So these are proteins that help hold the gut cells tightly together. And these can sometimes show up higher in levels with people with coeliac disease, IBS or Crohn's disease, which is why it's also being used as a potential marker of leaky gut as well. Lots of these markers have not been well validated yet. For example, zonulin test kits that you can find online, many of them actually don't detect zonulin, they pick up similar molecules that may not be reflecting gut leakiness at all. So whilst I think all these blood markers sound promising and are easy to use, scientists are actually still figuring out how accurate they really are. And if you've done any one of these or you're thinking about using them, honestly, interpret them with extreme caution because the results you get might not be reflecting the real state of your gut barrier at all. Okay, let's do a bit of a summary because I've thrown quite a bit at you here. We've done a general overview of leaky gut. Your gut should be leaky, but not too leaky. Despite the leakiness, your gut defenses are incredible. You can and should be able to get a lot or throw a lot at your gut. And the third thing is, it's difficult or near impossible to measure the leakiness of your gut. Okay. Now that's all said and done, let's imagine or assume that there is a leaky gut. So what would happen if there is excessive leakiness, excessive permeability of your gut lining? So if you take an extreme example of what would happen if you lack these mechanisms controlling what goes from the mouth in the digestive tract through the gut into the bloodstream, for example, in something that we know where this does happen, inflammatory bowel disease, the presence of erosions or ulcers, these actually allow bacteria to gain access to the mucosa that stimulate this exaggerated immune response. In these patients, we know that they do have a leaky gut and their guts are excessively permeable. So what happens? Not only do these patients suffer from the obvious severe digestive complaints, malabsorption of nutrients, blood loss that goes into the digestive tract and it ends up in the stools, but they also have what we call extra intestinal symptoms of their disease. So these are symptoms that occur outside of their digestive tract. And these are really far ranging. These can range from inflammation of the eyes, the joints, osteoporosis, skin conditions, liver conditions, even raised risks of different types of cancers as well. Some of these are related because of the process of inflammatory bowel disease itself, but others are related potentially to the damage in the gut, which is raises the inflammation level in the body. The question is, aside from patients with diseases like inflammatory bowel disease, if there is subtle leakiness and so a much less exaggerated form of leakiness that we would find in an established condition from other factors, and we'll go into what these other factors might be, can this raise inflammation in the same way leading to both intestinal and some of these so-called extra intestinal symptoms? Can you find vague symptoms that can range from skin issues, brain fog, depression and links to other conditions from lesser extreme gut leakiness? That is the question. My personal belief is that I actually do believe so, but this is hotly, hotly debated. So I want to be really honest about this. My personal belief is that intestinal permeability can contribute to a chronic state of low-grade inflammation. So this is uh inflammation in the body that's not exaggerated, it's not it's not huge, but it's sort of simmering in the background, which drives a whole bunch of other processes, metabolic and physiological consequences that could have far-reaching impacts on things like your immune system, your brain, and even aging. But truthfully, and I do want to be really honest about this, there is limited data on leaky gut being linked to all these other conditions as far ranging as asthma, autism, Parkinson's disease, multiple sclerosis, eczema, the list goes on. It's because permeability is so hard to measure. And the studies that look at this phenomena, of which there there aren't many of these studies, they're shrouded in doubt and instead what we have are anecdotes of patients that have a consolation of some of these symptoms and seemingly unrelated issues who are diagnosed with this leaky gut uh syndrome, usually by a naturopath or a functional medicine practitioner or a holistic nutritionist. And then they get given gut health support, which is what we're about to talk a bit more about now, sometimes with a lot of supplementation that may or may not be having any effect whatsoever. And in some cases they feel better, which is why this sort of phenomena that you find on Google and stuff about leaky gut, fix your leaky gut, etc, etc, is beginning to to gather pace. So if we are to believe in the idea that because of excessive leakiness, both from small and large fragments that can slip through and trigger your immune system, causing low-grade inflammation over time and some of these extra intestinal symptoms, how can we avoid things that could lead to it? Thankfully, the basic things of what I would say for gut health more generally are the same things that I would say to prevent your gut from being leaky and and prevent leakiness from occurring in the first place. So despite the lack of robust ways to measure gut permeability in a patient, we do know from research papers that there are multiple things that may cause or worsen this process. And my first suggestion is remove emulsifiers and additives. So dietary emulsifiers are a class of compounds commonly found in processed foods and these can compromise the intestinal barrier function, potentially contributing to this phenomena of leaky gut. Emulsifiers are amphipathic molecules. It's going to make you feel really smart when you say this to some of your friends and family, by the way. Amphipathic molecules. And what it means is that they possess both hydrophilic, so that's water attracting, and lipophilic, fat attracting properties. So they're attractive to everyone. They're bisexual if you like. And this dual nature allows emulsifiers to keep fat molecules suspended in liquid environments. Um and this is really crucial in food manufacturing, which is why we find emulsifiers pretty um dominant in a lot of these uh shelf stable items. And just like bile acids that are natural emulsifiers in your gut, dietary emulsifiers influence how fats and water interact. And just like we have bile acids in our digestive system, you wouldn't assume that this is a problem, but they can interrupt or disrupt the mucus layer, reducing its ability to prevent bacterial contact with the gut. So what it's doing is it's disrupting some of those natural gut defenses that we have across the gut itself. And anything that disturbs that can potentially lead to a higher probability of this leakiness. Some examples of these additives, of which there are many, I can't go through every single every single one of them, are certain E numbers, so E471, E473, again, like I can't go through every single one, but uh some of the big ones are carboxymethyl cellulose or CMC and polysorbate 80, just to name a few. These are widely used in the processed food industry. And you know, for better or worse, you'll find them in baked goods, cakes, muffins, ice cream, frozen desserts, margarine, chocolate and confectionery, not the good chocolates, just just want to hasten that. Um peanut butter, not the good peanut butter, usually the ones that are um blended with palm oil. Um you'll find them in dressings, you'll find them in toppings, dairy creams, like you even find them in gel capsules and certain pharmaceuticals as well. These are uh pretty ubiquitous across the food industry because they are generally recognized as safe, also abbreviated to GRAS by the food safety authorities. Uh but emerging research is suggesting that frequent consumption, and I do want to really highlight this word, frequent consumption because I don't think, you know, if you were to have a few gummies or uh a bit of um pastry uh once a month or once every couple of weeks, it's going to give you a leaky gut. It's not going to occur that quickly, but frequent consumption, and unfortunately, a lot of us frequently consume these processed items. When they're combined with with other poor diet and lifestyle choices, this can all contribute to leaky gut or intestinal hyperpermeability. Some studies in mice show that emulsifiers can change the gut bacteria, which also leads to this extra leakiness as well, particularly in these mice that are genetically prone to inflammation. So we all have our different genetic levers. Some of us are more prone to inflammation, uh a higher rate of aging, um a worse approach to stress. So if you're a bit more prone to inflammation and you have this extra insult of some of these uh emulsifiers, it's another reason to be cautious about ultra-processed foods and pay attention to what's on the label. One thing that I I'm I'm learning a lot more about actually um through my work as chief science officer with Exhale is just how ubiquitous a lot of these processed items are in some of the healthy foods as well. So there are certain rules and loopholes that some of these uh like like health and lifestyle brands are able to capitalize on where they don't need to declare what's actually in the product on the label, which for me is pretty abhorrent. So you can hide things like maltodextrin, uh other additives in your product without declaring that on the label and say it's additive free. So a real, real big issue in the sort of health and wellness industry because they're charging you a huge premium, but they're essentially selling you an ultra-processed food. So really watch out on the label and do your research on the actual brand as well. It might surprise you that it's not just junk food additives that can harm your gut lining. So in mouse models of obesity and diabetes, researchers found that high blood sugar alone, also known as hyperglycemia, weakened the gut barrier, even without physical damage to the gut. In these mouse models, these scientists found that when the blood sugar is consistently high, like it is in things like type two diabetes or pre-diabetes, it changes how the cells lining your gut behave. Now, this could, and I just want to underline could because we're we're talking about mouse models here, but this could allow unwanted bacteria and toxins and fragments to leak into the body, triggering that inflammation cascade and even showing up in places like your liver and bloodstream as well. So, you know, obviously this is shown in a mouse model that isn't directly comparable to humans, but it gives me another reason to be aware of anything that's going to A, pose a risk for type two diabetes or B, cause persistent rises in blood sugar levels. And that actually includes things that aren't necessarily food related, things like stress or poor sleep. I'm a new parent, I'm having next to no sleep right now, and I know that this is having a negative impact on my sugar levels. I'm trying not to think about it to be honest because I know this is a phase that I'm going through and I'm pretty resilient in other areas of my lifestyle, but it does make me a lot more conscious about things that I know could potentially be pushing my sugar levels higher because of this potential association with leaky gut as well. The third thing, and I know I'm going to get a lot of slack about this, is alcohol. There is substantial scientific evidence that alcohol consumption can increase intestinal permeability and this effect is well documented in both animal studies and human clinical research. The mechanisms of how alcohol weakens your gut barrier is by damaging the gut cells, altering gut bacteria leading to loss of mucus and increasing intestinal inflammation. So when you drink alcohol, it's not just affecting your brain and your liver, alcohol and one of the breakdown products of alcohol called acetaldehyde are directly toxic to these tiny connections that hold the gut lining cells together, the junctional complex. And both lab studies and tests in healthy people, alcohol caused these key proteins like zonulin, for example, and claudin, which which keep the gut cells sealed together to move out of place, hence making the gut barrier weaker. And there's also evidence that alcohol can trigger certain response stress responses in the cells, causing them to contract and pull apart, leading to this like leaky pathway. So, I don't want to be puritanical here. While the occasional and moderate drinking may not have the same effect, the evidence strongly supports, at least to me, a link between alcohol and leaky gut when the intake is heavy or frequent. And I definitely think that look, there are varying degrees of sensitivity to alcohol across different people. I think this changes over time as well. Like for for example, I definitely find myself a lot more sensitive to the consumption of alcohol compared to when I was in my 20s, for example. And as harsh as it may sound, I actually think that this would be something to completely avoid in the presence of any symptoms that could be suggestive of uh gut barrier um dysfunction. So, just that's my top tip. Take it or leave it. It's up to you. Another thing is exercise. So, short-term bouts of exercise can increase leakiness of your gut. It's sort of like exercise is a stressor, but it's a good stressor in lots of ways. It raises your blood pressure, it raises your blood sugar, um you know, raises your heart rate, uh and it also causes leaky gut. But over time, we know that exercise supports great gut health. But excessive, prolonged exercise, particularly endurance exercise, marathon running, ultra marathon running, long cycling, this can be detrimental to the gut barrier and that's been shown in a few um uh studies as well. So, just something to to look at, particularly if you're the kind of person that gets uh quite sucked into high intensity interval training time and time again. It's a very stressful activity, or you're someone that really does go for long periods of endurance training at quite a high pace. Uh it's just something to to bear in mind. Uh usually a lot of these folks are also taking gels and quick releasing sugars to fuel that activity. And that in combination with the exercise causing the gut barrier dysfunction, it's just something to be wary of as well. And talking of stress, there was a really interesting study published in the journal Gut that investigated how uh psychological stress in the short term influences the permeability of the small intestine in healthy individuals. So what these researchers did is that they got their participants to experience stress by getting them to do public speaking. And they found that their small intestinal permeability actually increased. This is measured using one of the standard tests that assess how certain sugar molecules pass through the gut lining that we discussed earlier. So with all those potential flaws, I still think this is something that gets completely brushed over in the conversation about leaky gut. When you're under stress, whether that's giving a speech like in that study, or using social media, road rage, dealing with emails at 10:00 p.m., getting stressed out with how things aren't going to plan with your life, is that mindset, it's not just affecting your brain, it's impacting your gut as well. And so with anyone that is experiencing leaky gut symptoms, you know, before changing your diet, I actually think maybe changing your mindset is something that we could all benefit from regardless. Most of this conversation that we we have around leaky gut is is around food intolerance. You you'll claim, you'll hear claims from people that um eating gluten directly causes leaky gut in everyone, but there isn't actually enough evidence to say that. So I'd really think about your mindset as well as the different foods and things to remove uh before adding anything to your diet that could be quite extreme. So we've talked a bit about what things can potentially worsen or cause leaky gut if we can even say that. What helps protect it? So there there are certainly things that could definitely help protect the barrier and prevent leakiness in the first place. And one of the most interesting studies that I came across was a small study, but it was looking at polyphenols in the diet. Now, polyphenols, as a quick refresher, are the thousands of different chemicals that confer color and antioxidant and anti-inflammatory benefits when we consume them. We find them in fresh fruits and vegetables, you find them in greens and yellows and blues, they're, you know, even the beige colored uh ingredients. I know we we often um don't really think of those, but mushrooms and onions, they all contain polyphenols. The study was an eight-week randomized controlled crossover intervention trial where they were randomly allocated to start with either something called the polyphenol rich diet or the control diet, which was low in polyphenols. So following the first intervention period, there was an eight-week washout period to avoid any sort of carryover effects of of the intervention diet, and then they were switched to the other diet. So this is quite a nice, lovely designed study and lovely length as well. So pretty good, even though it was a small number of people. Um and this uh intervention diet, this polyphenol rich diet was designed to replace some of the low polyphenol foods with comparable products that are high in polyphenol foods. So they consumed around three portions per day of things like berries, uh blood orange and juice, pomegranates, green tea, dark chocolate, all the things that we always talk about here. And these polyphenol rich products provided uh a big increase in the number of polyphenols. So the comparable diets were like almost 1400 milligrams per day of polyphenols versus 800 milligrams of polyphenols per day. So a big significant difference there. Compared to the control diet, the polyphenol rich diet resulted in a little bit more consumption of dietary fiber, but not a massive amount. Um and it led to a a lower intake of animal and plant protein. So there were a few sort of caveats to this study that I think are important to recognize, but what it did show when they did a measure of the intestinal permeability, they were looking at zonulin, one of those proteins that sits in between the um the gut lining cells, they found that there was a significant reduction in the zonulin levels compared to the control diet. So potentially, getting more polyphenols on your diet could be helping maintain the integrity of the gut barrier, whether that or not that's because of the fiber or whether it's because of these actual chemicals that your gut microbes absolutely love to feed on is still questionable, but it shows me that getting more colors in your diet, eating the rainbow is a really good solid advice for anyone that is looking after or wants to look after their gut barrier. The second thing obviously is fiber. So short chain fatty acids, so these are they get bandied around quite a bit. Um they are produced by bacterial fermentation and what they do, I mean, these short chain fatty acids, one of which is butyrate, that gets a lot of attention because butyrate is one of the key sources of energy for your gut lining cells. And what they also do is that they strengthen that junctional complex, these proteins that stick in between the gut lining cells, uh and also reduce inflammation as well. And there are particular sources of fiber that increase the presence and abundance of what are called butyrate producing microbes. And these are things like grains, oats, uh certain types of uh uh soluble fibers that you find in green vegetables. And like I said, butyrate is a major source of nourishment for those intestinal cells. So where possible, increasing fiber would be a great uh strategy of uh improving your gut permeability or reducing the likelihood of gut leakiness. Interestingly, there is some emerging evidence uh on the subject of these butyrate producing species that omega-3 supplementation could have a prebiotic like effect. So that's a an effect like some of these fibers that increase the presence of these microbes that produce butyrate. We talked to Dr. Vijay about this on the podcast recently. And in addition to omega-3 having this uh fiber effect, they also are responsible for specialized pro-resolving mediators. These are these anti-inflammatory proteins um that could be uh having a positive effect on your gut barrier and just gut health in general. The subject of probiotics uh always comes up whenever we talk about gut health and whilst it seems like an easy fix and the presence of, you know, billions of colony forming units sounds impressive, uh it's really a drop in the ocean. And to sort of give you a clearer picture of the magnitude of effect, I'm going to refer to again, Dr. James Kinross, who I asked uh about uh with regards to probiotics and I'd like you to see his response.
Dr James Kinross: I advocate for probiotics in specific clinical use cases. I recommend probiotics to my patients in specific instances and there is evidence. There's not, you know, there's nearly 17,000 studies, published studies of probiotic uses in multiple different clinical scenarios where they have real value. So I'm not saying that they are not in and of themselves, you know, valuable. There is no question that there is mis-marketing of probiotics. And that's largely because they're trying to bypass EU regulations around health claims that they can make and they're selling into this nebulous wellness market, like whatever that is. I mean, who knows what the hell that is, right? So you can, you can say whatever you want because it's wellness. Uh and quite often these probiotics are contain lots of sugars and they contain lots of other um stabilizers that go into those probiotics which they don't really, you know, shout quite so loud about. And there's very poor advice given around how to take probiotics. And we are very bad at targeting probiotics to specific people for specific reasons. And and part of that is because um um we don't, that quite a lot of that information is missing. We don't really know how to target them. Quite a lot of probiotics strains, so lactobacilli and and bif and the bifidobacteria are actually derived from, you know, non-human sources. They're not really designed to be in your gut, you know. Um I don't think a lot of people realize that. No, they're not, they're not, you know, they're not, they're not found in humans and discovered in humans because they're natural members of the human gut. You know, they are artificially being placed into that gut. And this idea, I think many people think that you take a probiotic and suddenly your gut blooms into this diverse ecosystem. That's absolutely not what's happening. You know, and you read these probiotic formulas and they say, oh, it's got, you know, five, you know, billion colony forming units. You think, well, God, that's a lot. But then you think about the fact you're dropping this into 100 trillion, a community of 100 trillion bacteria. It's like a drop in the ocean. And it's maybe one strain or two strains or five strains, you know, where there should be 500 or 1,000 strains or or species. So these things don't necessarily change the community structure of the microbiome. They don't change the wholesale function of the microbiome, but they might have very specific health benefits in very specific use cases. For example, lowering cholesterol, right? So if you've got a high cholesterol, actually there's pretty good evidence that taking a regular probiotic, that means waking up and doing the opposite of what I've just said, taking it every day for at least a minimum of 12 weeks and then measuring what your cholesterol was before and after and demonstrating it has an effect because if it doesn't have an effect, then you're wasting your money and you need a different strategy. And maybe you're on the wrong probiotic and maybe you need to change again. So, so I think um it's I I think the point that I'm trying to make is it's a nuanced topic and it's not a panacea. Taking a probiotic, you know, one of these kind of endlessly marketed probiotics is not going to suddenly make your gut healthy, but it might have a very specific health benefit if you're taking it for the right reasons.
Dr Rupy: So let me round up leaky gut for you again because I think we need multiple checkpoints here. Number one, we all have a degree of permeability, that's normal. Your gut should be leaky. Number two, we don't have strong proof that increased permeability actually causes the issues. And there's no validated blood or stool test to diagnose leaky gut despite what some companies might claim. And the other thing is that there is no supplement, no probiotic or intervention that is recommended with the exception potentially of things like omega-3, but there are some simple strategies to keep your gut barrier healthy, like polyphenols, fiber, avoiding additives and alcohol. So, what is my sort of go-to every single day to improve my gut health and protect my gut barrier? It's BBGs. Beans, berries, greens, seeds and nuts every single day. It's just a really simple, useful way of ensuring that you are getting enough fiber, you're getting polyphenols, those beautiful colors that you get from different berries and greens, and you're also going to be providing not only those nutrients for your gut, but also for your health as well. Seeds and nuts have got lots of different types of proteins in, they've got fatty acids that are anti-inflammatory. Getting BBGs in every single day is just a really simple strategy. First, aim for a handful of each, a handful of cooked beans, a handful of berries that could be fresh or frozen, a handful of greens. I try and get greens in at every single meal time where possible because greens are not just great from a polyphenol perspective, but they're also really rich in magnesium and magnesium is responsible for so many different processes in our body and we tend to be deficient in magnesium, which is why a lot of people supplement with it, but just go to the whole source. And then seeds and nuts, I just think are a wonderful addition to your diet because of those fats, because of the plant protein and because of the fiber content as well. It also gives you diversity. Now, I know that there is this uh trend towards as many different plants as possible every single week and aiming for 30 plants every single week. We actually talked to Dr. Emily Leeming about whether we actually need to aim specifically for 30 plants a week. Here's what she had to say.
Dr Emily Leeming: For me, I just find that the 30 plants a week message is getting talked about like it's the new five a day, which is based on thousands of rigorous studies. Um actually, you know, let's just have a bit more nuance when we talk about it. If it doesn't work for you, then don't worry. And if we can focus on actually the things that um you know, diversity in an easy way, which is having a range of different colors on your plate, um going to the supermarket and getting that mixed bags of veggies. I love those stir fry mixed bag of veggies. Um going to the freezer section, getting fruits of the forest, there, you know, getting the kind of mixed cans of beans. Many ways that you can just make diversity really simple for yourself without necessarily having to be religiously writing everything down.
Dr Rupy: So whilst 30 plants a week could be a really good thing to aim for, it's not a magic number. I still think it's a useful way of looking for diversity in your meals, but I don't think we need to be rigid with targets. And at Doctor's Kitchen, this is exactly how we design our recipes, especially in the gut health goal on the app. So every meal is built to hit these big targets. Over six plant points per dish to support this diverse microbiome, over 30 grams of fiber a day if you follow a couple of the recipes. We try and get a mix of prebiotics. These are specialized fiber-rich foods like leeks and lentils and oats. You get polyphenols. We're really big on polyphenols from ingredients like herbs and just simple culinary herbs as well. It doesn't need to be exotic spices like turmeric every single time, even though I'm a big fan of turmeric. Berries, nuts, cocoa, these are great. And then optional fermented foods like yogurt, kefir, miso or kraut. We try and make it easy on the Doctor's Kitchen app and you just go to the Doctor's Kitchen app and you just type in the gut health goal and we'll give you a rich list of different recipes that will give you variety, they'll leave you inspiration and we hope your family as well will absolutely love them. I really hope you enjoyed this episode that we did specifically for World Gut Health Day. You're a lot more confident about leaky gut, you know how to approach leaky gut, you shouldn't be scared about leaky gut and how there is actually some validity but a lot of unknowns around this phenomena as well. I really hope some of these strategies are going to help you support your gut barrier and let me know in the comments if we've missed anything and you want you want us to explore any more of this subject because I'm sure you're going to have lots of questions as well.
