The Diary Of A CEO with Steven Bartlett - Most Replayed Moment: Are You Really Gluten Intolerant? It Could Be This Instead!

Episode Date: July 10, 2026

Your gut symptoms might not be caused by gluten. Dr Will Bulsiewicz is a leading gastroenterologist and gut health expert specialising in the microbiome, digestion and the science of food. In this moment, Dr Will Bulsiewicz reveals why bloating, gas and constipation are often misunderstood, and why the real trigger behind your symptoms might not be gluten. Learn how your microbiome is quietly shaping your digestion, inflammation and long-term health.  Listen to the full episode here! Spotify: https://open.spotify.com/episode/32c3lvtL5rrQQiAs8QbJsW Apple: https://g2ul0.app.link/WGPl0LtXB4b Watch the Episodes On YouTube: ⁠⁠https://www.youtube.com/c/%20TheDiaryOfACEO/videos Dr Will Bulsiewicz: https://theguthealthmd.com/

On this point about bloating discomfort, regular digestion, if I have one of those things, does that theoretically mean that something is not right? Everyone gets bloated once in a while. So I think it would be unfair to make it sound like you should never have any adverse symptoms at all. But if it's prolonged. But if it's prolonged, if it's a chronic health issue, if you're the type of person who you wake up in the morning and you say, I hope today is going to be a good day, I hope I don't have to deal with that specific issue. you have a problem.

Like we already know. And then we have to work on that to address that issue. And how we go about that, I think, needs to be on some level personalized. But the tools that are at our disposal remain the same. So it's just a matter of like, let's put it on the table. Here are your choices. You pick which ones are most applicable to you. Where are the opportunities for you?

And I can't tell you that without knowing more about you. What about this issue of people getting gassy, like farting a lot? Yeah. Is that typically associated with one particular gut issue? Or is that, again, could that be a plethora of issues? So it could be a plethora of issues. This is a common problem. If I have to like start with what is my number one thing, it's constipation.

For sure. 100%. There are so many people who are listening right now that are constipated and they don't even know it. Because they poop every day and they think that how often they poop is the definition. And that's not true. So constipation is what happens when you're not adequately emptying your bowels. And that could be a frequency problem, but it could also be that it's a partial poop. Oh, okay, because I thought constipation was, if you just haven't been, you can't go, you go to the toilet and nothing comes out.

Look, don't get me wrong. If you don't poop for a week, I know you're constipated. I don't need to ask any more questions. If you go a week, but if it's, there are people who they poop every other day, that's their normal. they feel fine, they don't have any gut symptoms, they don't have a constipation problem, we're okay, right? So frequency is not the be all and end all? It's part of the equation, right?

But there's also people who they poop and I want to sort of paint the picture and forgive me, I feel very comfortable talking about poop. This is what I've done for a living. But they go to the bathroom in the morning, they struggle. It's not satisfying. they had to work really hard to get a little nugget to come out. And then they feel like they still have to go. And maybe 45 minutes later, they poop again.

Okay, that's not a new poop. You're doing partial poops. You're probably doing a 20 or 25% poop. So you could poop three, four times during the day. You might not still be fully emptying your bottles. Right. And so that's an example of a person who can actually be struggling with bloating and constipation.

not think because they're like, Doc, I'm pooping three times a day. Where is the gas coming from in that? Why do people, you eat something and then you fart a lot? What's going on? So gas travels with poop. You may, I don't mean you specifically, Steve, people listening may notice this that you wake up in the morning and you're farting like crazy. And that farting continues until you actually have your morning bowel movement. And then once you have your good, healthy morning bowel movement, you feel solid and you're not farting anymore, right? The gas travels with the poop. So, and the reason why this happens is because, first of all, your poop is not just the leftover remains of your food. Actually, your poop is predominantly

your microbiome. 60% of the weight of your stool is microbial. Really? Yes. When you say microbial, you mean like the bacteria? The bacteria. 60% of it. Let me give you an example. If I took your drink and I added some soluble fiber, which is pre-botic, into your drink. There's no grit. There's no roughage. You don't even know it's there. And you're going to have a bigger, healthier bowel movement tomorrow as a result of what I just did. Why?

Because I fed your microbes and they grow stronger and then they multiply. And because they multiplied, you have a bigger bowel movement. Right. That's the way that that works. Now, don't get me wrong. you eat, you know, a salad, you're going to end up with a bigger bowel movement as well. But a big part of that is the fiber within that salad that's feeding these microbes, they multiply, they grow, and you have a big bowel movement. So if that was my, if that was my, my stool, my poop, I'm holding a chocolate bar here.

60% of that would be the microbes. 60% of that would be the microbes, yes. So for that person, when the poop is in gridwalk and it's not moving through, then those might be. microbes are basically sitting there with unlimited time to ferment and produce gas. Okay. So anything they come into contact with, they're just going to start working on it. And it's not just like a fiber thing. Anything they come into contact with, it could be protein.

They will ferment it. They will produce gas. So this is a big part of the reason why constipation is so strongly associated with gas and bloating. When people eat dairy and things like that, I think some people that have gluten, they often tend to get a little bit gassy. Yeah. Is that constipation? Gas and bloating is not just a constipation issue. I would argue that constipation is the number one cause of that particular issue, but there's many potential causes. Number one could be motility, that's constipation. What's motility? Motility is the way in which your intestines move. So if the intestines move too fast and out of rhythm, you get diarrhea. If the intestines slow down too much sluggish, you get constipation. We want the intestines.

in a rhythm because when they're in a rhythm, just like your heart, that's when they perform their best. So in a rhythm basically means predictable, consistent daily bowel movements. That's ultimately where we would love to be. And that, in a way, taps into like an entire circadian conversation that we can have later. This is a part of your circadian rhythm is a fantastic morning bowel movement. Motility is just one of the causes of gas and bloating. The second is the microbiome. if you have a microbiome that's damaged and struggling, it's not going to be able to do its job the way it's supposed to. And part of its job is processing and breaking down fiber.

Because the fiber in our diet, we don't have the enzymes to digest it. So it works its way through the intestines, comes in the contact with the microbes, and the microbes, they have literally 60,000 enzymes that we don't have as humans. They go to work as teams. Fiber stops being fiber, produces short chain fatty acids. This is the way that it's supposed to work. When your gut is not happy, they're weak, the microbes are weak, and you're asking them to do work, and they can't handle that.

And you end up with sloppy digestion, and that's gas and bloating. The third thing can be your diet. So you just mentioned dairy, which contains lactose. Lactose can be easily fermented to produce gas. You mentioned gluten. Gluten itself is a protein. So can gluten technically be fermented? Yes, it could be technically fermented,

but that's not really what's going on. What's happening is that gluten-containing foods, which are wheat, barley, and rye, also contain these carbohydrates called fructans. And fructans are actually really good for our microbes. They're pre-botic. But if you consume a very large amount of them and you're not used to eating these foods, it can cause gas and bloating. These days, when I was younger, if I had pasta, I was fine.

If I have pasta these days, I'm going to feel it for the next, like, two days. Really? Yeah, I don't know. I don't even know what's going on. But then other people can eat pasta as much as they want, it seems. Out of curiosity, can you go to Italy and eat pasta and be okay or no? Same thing. I haven't really not really tried.

Okay. anecdotally, I think when I remove, when I have like non-glutin bread or non-glutin pasta, I think I feel much better. But I'm well aware from speaking to people like yourself that such a small percentage of the population is actually gluten intolerant. But we all kind of think we are to some degree. I think it's what's the numbers? Is it like 20% of people think they are or something? So like here in Los Angeles, it's like probably 80% of people.

Think they're, well, like almost everyone's gluten-free, right? Which they don't need to be. And actually, it can cause problems. It can cause problems to be gluten-free unless you know what adaptations to make. So when you ask that question about Italy, what are you getting at? There's a processing issue in the United States involving wheat, which is that they allow the wheat to be sprayed with glyphosate, which is round up. It's a weed killer. And they do that to basically dry it out as quickly as possible.

So imagine for a moment that you're a farmer and you have this field of wheat, you harvest it. Okay? Here are your choices, Steve. You can wait a couple weeks and let it dry out naturally in the air and store it somewhere. Or you can spray it with this chemical and it will be dried by tomorrow and then you can ship it up. Yeah. Right. And the problem is that glyphosate is not on the label.

You would never know whether it's sprayed or not sprayed unless you would. you're buying organic. If you buy organic, then by definition, they're not allowed to spray it. You would never know if it's there. The thing about glyphosate is that it's been approved to exist in our food system under the assumption of safety. Because what it does is it shuts down this thing called the Shikamot pathway. And that kills weeds or it kills plants. and we have a workaround. And it has to do with basically amino acids. We have a workaround where we can basically create those amino acids as humans, but the plants can't.

So the plants die, we live. But there's a problem, which is that the microbes that live inside of our large intestine, they don't have the work around. So that microscopic amount of glyphosate, you would say, well, us big humans, that's so small, what do you think happens when it comes in the contact with them? We know that glyphosate disrupts the microbiome, that it depletes the beneficial bacteria,

and the ones that tolerate it the best are the inflammatory ones. The bad bacteria. The bad bacteria. So you're shifting the balance. And this is a small thing, but I hear from people, Steve, that go to Italy, they say, I can't eat wheat in the United States. and then they go to Italy and they're fine. And you think it's that glyphosate.

Yeah, they don't do that there. So if I tried, I'll try organic pasta tonight. And maybe that will be better. Yes. And then like the alternative choice is, how do you do with bread? Are you okay? Not all bread. My, generally I stay away from bread.

Okay. Do you ever eat sourdough? Yeah. Do you do okay with sourdough? Yeah. There we go. So here's the second part of this equation. Put the glyphosate, put that to the side for a moment.

Let's talk about the fructans that we were talking about a moment ago. When you ferment your wheat, when you ferment your dough, you actually reduce the fructan content. What's fructane? So these are the long chain carbohydrates that exist in wheat, barley, and rice. So if it contains gluten, it also contains these fructans. Like, gluten is not the only thing in wheat, right? And these fructans, again, they're good for you. they're good for your microbiome, but people who have a slightly damaged gut, they struggle to process and digest them.

So this would explain why some people, they eat, they eat, you know, wheat-containing, gluten-containing foods, and they struggle. But they do okay with sourdough, because if you ferment the bread, it reduces the fructant content, and actually then you can tolerate it. Oh, okay, so you think it might be the fructane in the bread that I have an issue with, and sourdough doesn't have fructane in it? Yeah, there was a study that was in gastroenterology a few years. Gastronerology is the top journal in my field where basically they sent people home with a bunch of breakfast bars, all right, not chocolate, but nonetheless. They sent people home with a bunch of breakfast bars, three of them. One of them was a placebo bar, so they didn't add anything special. One of them contained a very large concentration of gluten.

And then the third one contained the fructans. and the placebo is our standard. We're going to compare to that. When people ate the gluten-containing bar, and these were, by the way, people that they did not have celiac disease, they did have gluten problems according to them, right? So, like, this is like the 20% of people that you mentioned a moment ago who think they might have a gluten problem.

When they ate the gluten-containing bar, they actually had less symptoms than the placebo. So, in other words, the gluten-containing bar, the gluten is not the problem. But when they ate the fructant containing bar, they were triggered. So basically what this said is that we have been taking this concept of gluten intolerance, and we've misnamed it.

It's not a gluten intolerance. It's a fructan intolerance. These are people who are tending to struggle with these particular parts of that food. What foods contain fructane? So wheat barley and rye. Okay. And different, there's many different types of fructans, by the way. So you may not react to all of them.

You may react to just some of them. But like garlic and onions are also classic. So you hear people who are like, I can't eat garlic. I feel terrible. Right. That can be a fructan issue. Teph, amyth, sorghum, quinoa, these are whole grains that don't contain gluten. and they also don't contain fructans.

How long does it take to repair the gut when you have done damage to it? That's a very broad question intentionally, but generally, for the average person who's done who's sort of irritated their gut, how long does it take to restore and for those microbes to go back? It really depends. You have to start with, okay, what's your starting point? Right? Like, how deep is the damage? How bad is it? Because for the people, people who have ulcerative colitis or Crohn's disease, those are forms of inflammatory bowel disease. Those people have the deepest dysbiosis. Disbiosis is the word that we use for a damaged gut. Is it possible to reverse that? It's possible to put them into remission so deeply that they don't have a

flare. Is that what the flare looks like on this little model that I have in front of me? Yes. So going back, for the people who are listening and not on YouTube, you can flip over to YouTube if you're interested. But what I'm showing here is the model of the large intestine. And the model includes a little area that it looks raw, ulcerated. It's bleeding. If you, if you were to bump up against it, it's going to start to, you'll start to see blood coming out. So it's like a, it's a very vulnerable, sensitive area. Now, these inflammatory bowel diseases, Steve, I have an interesting study on this topic. They are to me the classic gut inflammatory health condition. And what's happening is the immune system is attacking the microbiome. So technically,

it's not actually autoimmune. Because autoimmune would be you're attacking your own body. The immune system's not attacking your intestines. The immune system is attacking your microbiome and rejecting it. And because that's happening, your intestines are stuck in the middle. So this here is the immune system attacking the microbelemen. It's attacking the microbiome, which is in the tube of the large intestine, and the immune system is trying to get at it and kill it. Why? And because it's decided that it's the enemy.

So the immune system is confused, because when we're born, we don't have much of a microbiome at birth. It's the closest that we will get to not really having anything. And then during the first three years of life, you build your microbiome through your life experience. And by three years of age, you are basically fully adult-sized in terms of your microbiome. During this time, your immune system is learning from and with those microbes. So there's this interplay between the two that is undeniable where when the microbiome is healthy during childhood, during those first three years, it results in a healthier immune system.

So what's going on here? The immune system is supposed to acknowledge your microbiome as being friendly, and it does not. It decides that your microbiome is the enemy, and so it's taking it out. So what do you think is, for someone that has like irritable bowel syndrome or Crohn's disease, or they, you know, they have one of these big sort of ulcers in their small or large intestine, is it because of their lifestyle, typically? So lifestyle change or is it lots of things? What's the number one perpetrator? Okay. There's clearly a genetic component. Okay, so we have to be up front about that. Like, these are things that are not necessary within a person's control entirely.

Because, I mean, there's no evolutionary reason why this would happen. Like, there's no evolutionary reason why you'd have severe gut digestion problems. No, it's not too much. There's no advantage to it at all. And these things that occur, they were quite rare years ago. In fact, in third world countries, today, there's not much inflammatory bowel disease. There's not a lot of Crohn's disease and ulcerative colitis in third world's countries. If you go to Africa, there's very little.

And then what you see, though, is as countries industrialize, there's a takeoff and they start ramping up. So within the United States, over the course of 40 years from 1970 to 2010, also of clitis and Crohn's disease cases were increasing by up to 55%. And you can get that at any age. You get that at any age. Even if I'm healthy right now, I could do a set of things that would give me this. Yes. In fact, if you take, so back to our conversation about antibiotics, if you take antibiotics, your risk of developing an inflammatory bowel disease in the next year just doubled.

Oh, gosh. If you disrupt the gut with antibiotics, which the antibiotics do, there's nothing that will basically like decimate the gut faster, reducing gut diversity, disrupting the gut barrier by 50% during a course of antibiotics and activating the immune system. It really speaks to that, like if you take antibiotics, these risks of inflammatory health conditions really start to go up. We see this in both adults and kids. What you just listened to was a most replayed moment from a previous episode. If you want to listen to that full episode, I've linked it down below.

Check the description. Thank you.