Welcome to Zoe, Science and Nutrition, where world-leading scientists explain how their research can improve your health. Today, we're talking about inflammation, critical for our health, but often misunderstood. What if I told you that your gut could be a source of chronic inflammation? And that this inflammation can cause serious conditions like type 2 diabetes, heart disease, and even cancer. And then, what if I told you that it's possible to reverse this? The good bacteria in your gut could actually reduce your inflammation? Today, we're joined by two giants in the world of health, nutrition, and the microbiome, Professor Tim Specter and Dr. Will Balsawitch. Tim and Will are here to help us learn how to lower inflammation and improve our health. Tim is a Professor of Epidemiology at King's College London, a leading authority on the gut microbiome, and my scientific co founder here at Zoe. Will is a board-certified gastroenterologist, New York Times best-selling author, gut health expert, and Zoe's US Medical Director. Tim and Will, thank you for joining me today. So you know the drill. We are, of course, going to start with a quick fire round of questions from our listeners. And for anyone who's new to the show, that means that you can give a yes or a no, or if you absolutely have to, a one sentence answer.

I'll start with Tim. Can inflammation cause serious long term diseases?

Yes.

Will, if I have high levels of inflammation in my body, will I feel it?

Possibly.

Tim, can what I eat lead to inflammation after meals?

Definitely.

Will, could improving my gut bacteria reduce inflammation throughout my body?

Absolutely.

Then for both of you, what's the most surprising thing that you've discovered about inflammation?

I would say that inflammation is about more than just the immune system.

I would say that inflammation is actually about how our body repairs itself and is crucial to aging, body repair, as well as all our immune functions. So it's incredibly important we get it right.

So I'm really excited by this episode, and I think those answers tee up why, because I think most of our listeners are going to be like me, which is before I met Tim and Sarah seven years ago, I hadn't paid any attention to this idea of inflammation. And actually what I'm struck, as I've met more and more scientists over in the last seven years with Zoe, is how often they focus on inflammation. Now, what I do understand now is that it connects to the health of our gut microbiome, the trillions of bacteria in our gut, and that it can be seriously harmful to our health. But after that, it all gets very complicated. So I'm really excited to have both of you here to be able to explain that in a very simple way, but also then to really take us through lots of actionable advice about what we can do to reduce inflammation inflammation and improve our health. I guess I'd like to just start with the simplest question, what is inflammation?

I would define inflammation as activation of the immune system. And that activation is typically in response to what the immune system believes to be a threat. Now, whether or not it's actually a threat is a different question. But the immune system essentially has said, it's time to go to work. We must protect and defend the body, and therefore the immune system gets activated.

And Tim, is inflammation good or bad?

Essentially, it's designed by evolution to be good. We'd be dead without it because our body wouldn't react to anything from a small cut against a rosebush to stop us bleeding, to preventing scarring or fighting off some little microbe that was trying to get into our mouth and into our guts. So we all need inflammation. And generally, we talk about this as acute inflammation, short term inflammation. And it's when this normal response gets continued on that you get what's called chronic or long term inflammation. And that's when the body is in a permanent state of heightened awareness. So it's like looking for a fight all the time, but often inappropriately, because there is no more infection. There's nothing else. It's being tricked into thinking it's got a fight. And that's where we have a problem.

And the analogy that I think about a bit is, I think as you both know, I broke my toe a year ago. I smashed it into pieces. And there was definitely a lot of inflammation in that toe afterwards. It swells up to this enormous size. And what I understood, in fact, you were explaining to me is that inflammation is good. It's all of this process that the body has been triggered to actually go and heal this wound. And interesting, it lasted for quite a long time. I would say the inflammation didn't fully recede, probably for more than six months in that case, but it has now gone. And so I think you're describing that as an example of inflammation working in the way that it's intended, Tim?

That's right. It's designed there to open up the blood vessel You get extra fluid in there, and that, in a way, gets rid of the debris and the damage. And then also it sends signals to white cells to come out of your blood, get into that system to start repairing the damage. And so this whole cascade of events, which leads to you getting a swollen, a red, a painful dilated toe, is exactly the defense mechanism that you want. And you notice it as swelling, but eventually you get inflammation around the cut. And so you get new cells being driven to that place, and they start repairing and laying down new skin. And eventually the whole process after a few months, pretty much goes back to where it was. That's our normal system. So generally, what we've discovered in health is that most This pathology is when normal defense systems go a bit wrong. And this tends to increasingly occur with age. And as we get slight little defects in how these things happen, often the body is reacting to something it thinks is a threat, but actually it's its own tissue. And your body would go on and attack its own skin, causing funny rashes, or it might attack its own joint, thinking actually there's some There's a microbe in there that it's got to get rid of.

And that's why people get long term arthritis and skin disease and in the gut might also get gut colitis because the body is reacting against itself in the same way to your injury.

And so if inflammation is good in these examples, I guess the obvious question is, why is it bad if it keeps on going? You might think that it's great to have it just always on. So help us understand why it's not good if there's too much of it.

Well, there's always consequences. There's always consequences to activation of the immune system. So when it's in an acute setting in response to an infection or to bodily injury, those consequences are worth the price of admission because you're defending the body in a way that's necessary. But when we're talking about unnecessary chronic inflammation, which is really the root of the issue here, the consequences that we receive are not ones that we want or intend, and they can have effects throughout our entire body. Tim mentioned autoimmune diseases, and we could add allergic diseases to the list of classic inflammatory things. But actually, the list goes far beyond this in terms of conditions that are associated with inflammation. And in many cases, conditions that people would never even think they actually are inflammatory. And so it's important for people to understand that this goes far beyond beyond just what we think of as the immune system and activation of the immune system. This is more nefarious in the big picture in terms of our health.

And well, just to make sure that I've got that, what you're saying is if you have this long term inflammation for years rather than just days or maybe months, actually that increases your risk of really serious diseases like heart attacks and cancer and things like this.

Absolutely. And And if we go through the list of the most common causes of death that affect our two countries, what you'll find is that the top causes are all inflammatory diseases. So coronary artery disease, cardiovascular diseases, stroke, different forms of cancer. The vast majority of forms of cancer are inflammatory as a result of long term inflammation. Diabetes is an inflammatory disease. Obesity, Alzheimer's, these are all inflammatory conditions.

So it sounds like you're saying basically inflammation is this hidden cause of almost everything that probably people who are listening to this are worrying about, or at least it's one of the causes.

I don't think we want to spend the hour doing this, but I could easily generate a list of over 100 health conditions that are associated with chronic inflammation. The thing that's important for our listeners to understand is that you may go to five different doctors for five different health conditions, but the root cause that ties them all together is inflammation. The And the frustrating part of that is that if that's what ties it all together, why are we not talking about this more? That's the part that's frustrating.

Well, I think everyone's probably paying attention at this point. And I guess the follow-on question is, is there more of this long term inflammation today than in the past? Because I think we are obviously aware that there seems to be this big rise in these serious long term chronic diseases compared to the past.

I think we're seeing a change in the past. People had chronic infections. So it was very common for people to have tuberculosis, for example, which was the classic example of an acute inflammation that keeps going because you can't get rid of the bug that causes the tuberculosis. And so your body continues to react against it, and you get a similar effect with things like leprosy. And so often these chronic inflammatory conditions were related to an original infection. And we've moved really into an era where we're not being exposed to as many bugs and infections, but we now have these increased level, these autoimmune diseases and these life are Western diseases that now have an inflammatory component. So I think we've changed from modern living, from living surrounded by microbes, having a really strong immune system, to suddenly moving to modern life in its sterile form with poor diets, meaning that we suddenly are much more prone to things like food allergies and maybe some of these food allergies, triggering longer term autoimmune diseases and chronic gut issues. In a way, the defense system hasn't changed, but the challenges have, and maybe it's not as well primed in childhood as it was in the past.

And that's one theory as about why we're getting more of these problems now on top of, of course, our terrible diet.

And there's a question that is a classic science question, which is, is it nature or is it nurture? Is it genetics or is it the environment? Tim, you've spent your life studying this question. Genetics don't shift in humans that quickly. Now, in microbes, they can shift very quickly. But in humans, we don't have the capacity or ability to do that. What has changed is our environment. We spent millions of years living in a pre-modern environment, pre-agriculture environment. Then we spent 12,000 years in a slowly adapting, slowly changing agricultural environment. But really, if you think about it, we reached a point where science and technology took off in the last few hundred years. As science and technology took off, we became evolutionary pioneers as humans. In the process of doing that and allowing science and technology to shape our environment, change our environment radically, even in the last 100 years, what we've lost sight of is that those changes have an effect on our body, those changes have an effect on the microbes, and the microbes are responsible for training our immune system.

Yeah. That's why food allergy really was unknown to medicine before, about 1969, when man walked on the moon. And now it's one of the commonest things you see in schools. So Something quite dramatic has happened in our interaction of our immune system to train it when we're kids. That was really different before and after that watershed time. I think that's really fascinating. Fascinating, and that's really just a glimpse of what is happening in many other diseases.

I just want to pause for a second.

I thought this episode was fantastic. I hope you've learned something. As a Zoe listener, by now, you probably know a a lot about the gut microbiome, but wouldn't you like to know how yours is doing? As part of being a Zoe member, you receive an at-home test that will reveal the exact bacteria that are inside you and show you how to improve your gut microbiome. I do this regularly, and it's had a massive impact on my health. I and the whole team at Zoe would love you to join us and become a Zoe member. We do realize, however, that not everyone is ready for personalized nutrition and that for others, it's still too expensive. And that's why we put this show out for free each week without ads. If you are ready for Zoe, then go to joinzoi. Com/podcast and get 10% off so you can start your own journey to improve your health today. Right, let's get back to the interview. I think what you're saying is levels of long term inflammation are much higher than in the past, and particularly that when When you had them in the past, I think you were saying, Tim, that often came from some active disease that you had, like leprosy.

I haven't met a lot of people walking around the streets of New York or London or LA with leprosy. So I feel that is no longer the core driving issue of inflammation. Is this fair, Tim?

In India and Nepal that I visited, there's still many leprosy hospitals, but TB, its cousin, is very, very common.

Got it. But in terms of driving the rates of cancer and diabetes and all the things you're talking about, it's not leprosy or TB that is causing this anymore, correct?

That's correct. Yeah, that's right. And that's just the way the immune system is working differently.

And so what you're saying is there's this really high level of inflammation over years that's been caused by our environment. Most people listening are over the age of five, right? They can't change what happened in those first five years, but clearly, they have a lot of control over the food they're eating and maybe some other aspects of their environment. So how does food play into this this story of raised inflammation?

Well, until recently, food was vaguely discussed in terms of pro-inflammatory diets and these things, but there wasn't really much science to back it up. It was fascinating when in the Zoe Predict study, Sarah Berry was leading this work and found that when people had very large sugar spikes, and particularly fat spikes after a meal, remember these vary tenfold between people. That was also associated with big increases in inflammatory markers. These are telltale signs in the blood that your immune system is really activated and trying to kill off other things and being very aggressive. And so most ultra-processed food would cause, in some people, these really inflammatory spikes. And if you were having a snack every two or three hours, You'd be triggering this inflammation every few hours for 14 or 16 hours a day. So your body was in this state of high tension, excitement. The immune system was, come on, waiting for someone to attack and would sometimes mistakenly attack things that it wasn't supposed to and really fool the body to think it was in a war footing. And that's what many people in our populations in the Western world are constantly in who are eating junk food regularly.

Their body thinks it's in a crisis situation. And so everything is going full alert. It's not trying to repair itself. It doesn't have time to repair itself. It That's really sending out all the wrong signals to the body. And that's why we get these problems in all these other organs, in our brain, in our heart, et cetera. So realizing that certain foods in certain people will cause these inflammatory spikes is really important. And we also know that I've got microbes can dampen that down as well. So that's also really important that as well as our genes, which partly control our immune system. We've also got the genes in our microbes that also can produce anti-inflammatory dampening down signals to put out these hot embers. So it's been likened to lighting lots of fires, which normally are fine, and they go straight out. But if you keep doing it, it's like you've got these hot colds in your body in a permanently heightened state, which means that you can't function normally. You can't do the normal repair processes. You're more likely to miss a cancer, you're more likely to badly repair somebody's body so you age faster.

This is, I think, the modern equivalent of what long term inflammation is doing to us all. And basically, our diet and our gut microbes are at the heart of it.

It's a slightly scary story, isn't it, Tim, that you talk about? You touch a little bit on blood sugar and blood fat. Could you explain a little bit more about what's going as somebody is thinking who maybe is new to this and they're thinking about they're eating something, how does that link through to the spikes that you're talking about?

We see in studies that we did, like the ZOE Predict study, people are wearing a blood sugar monitor, so we know what their blood sugar levels are every few minutes. And when you eat something like a breakfast muffin or a cookie, after around 30 minutes, you'll get a peak in your blood sugar. And after about two to four hours, you'll start to get a peak in your blood fats. And at those peaks, That means your body's under stress if it stays there too long. And we think the body is seeing that as a threat it has to deal with. It's causing some general stress to the system. And in response, the body then pumps out these inflammatory chemicals which are arming the immune system to help deal with it. In a way, help deal with getting that fat out of the system and trying to initiate some pair. And it's a failed system because it's never really going to work in that way. And that's why we think that people who have too much fat in their system, say four to six hours after a meal, these little particles of fat gets stuck in the blood vessels and they trigger even more inflammation.

And that irritates that whole system and makes it more likely over time to build up plaque and heart disease. So We think there's a real link between not only what you eat, but how you respond to that food, how quickly you get rid of it, and how big that immune reaction is to it. You put those things together. It's a nasty cocktail for many people.

You know, Tim, one of the things that filled in some of the puzzle pieces for me when I read that study, the Predict study that you and Sarah were a part of, was that the inflammation peaked six or eight hours after the meal. So there was this buildup and lag that took place. And if you think about this, people who are snacking 10:00 at night, you're essentially kicking your body into a constant state of inflammation because that's peaking in the middle of the night and then just starting to come down, you wake up in the morning and it just fire it back up again.

And that's why fasting overnight is probably useful because your body can get dampened down that inflammation and why you continue snacking generally is pretty bad for your metabolism.

I think some people listening is supposed to say, well, hang on a minute, you're saying I can't eat, but I don't think that's the message, is it? It's not that all food causes this or even that having a rise in your blood sugar or your blood fat is bad. They're talking about the way that these are really big spikes and over and over again in a way in which we probably didn't normally experience them before the foods we eat today. Is that correct?

Yeah, that's absolutely right, Jonathan. Until we did these studies in normal people, we didn't know what a normal blood spike of sugar or fat was. So we were still finding our way even back then in those first studies. But it's clear that many people can metabolize food and get a small spike, say in their fat, they clear it very efficiently, and there's little or no inflammation left over.

So it's not like all food is bad, right? It's something to do with the foods that eating today compared to in the past?

So definitely all foods don't cause an inflammatory reaction. And if you have, say, a bowl of mushrooms and lentils high in fiber, high in good fats and protein, you're very unlikely to see any inflammatory reaction. It seems to be really with fatty foods that we get this big reaction, and particularly poor quality fats, these saturated fats that you're having meals without fiber that you find in ultra-processed foods, and to a lesser extent sugary drinks as well. So it's those ones that cause a really big peak, say, six hours after you've had your meal, you've still got fat in the system. And then after that, you get this inflammatory reaction. So it's a long time after your meal, and It doesn't happen in everybody. There seems to be a degree of personalization with that as well. So I think it's, again, we're finding out more and more about how we all respond differently to foods. But for many people, eating bad foods regular intervals throughout the day, it keeps them in a high state of inflammation, which is in a high state of body stress.

So you've got this high level of inflammation because you're just eating all of these foods and probably your environment much. It's switched on too high all the time. How does the gut fit into that story?

We talk about the gut microbes on this podcast all the time, but there's a part of our body that I want to introduce that I think is critically important to this conversation that goes along with the gut microbes, and that's the gut barrier. So throughout our body, throughout our intestines, there is a single layer of cells. And And that single layer of cells has the responsibility of separating the 38 trillion gut microbes that are on one side inside our intestines from our immune system. 70 to 80 % of our immune system is on the other side. So first of all, people should know that the home of your immune system is in your gut.

Is in your gut?

It's born in the bone.

So I would never have guessed that.

And it makes a lot of sense because actually this is where, even though it's the deepest part of our body, Paradoxically, this is actually the place where we're interacting with the outside world the most. Our skin is a barrier. Our skin locks the outside world. But the gut, this is the place where, in a way, our intestines, it's like a beautiful river. That river brings clean water, and it brings the nutrients that we need that are life-giving. But at the same time, that river at times can be perilous. And there can be things in there that we would prefer to not come into contact with.

I'm going to try just for a second because I love... Only a gastroenterologist could say that our intestines were a beautiful river. I was just thinking about my poor little girl who was violently sick last weekend and vomiting everywhere. And whatever that was, it was not a beautiful river, Will. But I'll let you keep going with this beautiful river metaphor now.

Well, yes, I have an optimistic, beautiful view of the intestines, which is quite different from most other people. It's distorted. So nonetheless, US, this is the responsibility of this barrier, which is to allow us to recruit into our body the things that we really want, the things that we need, and yet simultaneously to protect us from perilous piranhas or whatever you want to call it, that we want to basically keep outside and leave it inside the intestines and ultimately poop it out. Now, these three parties, the gut microbes, the gut barrier, and our immune system, they're constantly communicating with one another, and they're working together. Our gut barrier that has this responsibility of protecting us, it actually renews itself every three or four days. We get a brand new gut barrier. By the way, the total surface area of our gut barrier is massive, larger than a soccer field, football in the UK. And yet every single blade of grass, there are There are microbes there that matter, every single blade of grass. The way that we ultimately set this up, Jonathan, is that we want a healthy gut barrier to protect us. The stewards of that gut barrier are the microbes.

They build the barrier, they fortify the barrier, they make sure that it's intact and able to do its job to protect us. When our gut microbes are healthy, they're able to do their job the way that they're supposed to. When our gut microbes have been beaten up and broken down, they're unable to fulfill their job, and part of their job is actually to help us to maintain that gut barrier. And when that happens, we are allowing access into our body things that aren't supposed to be getting in there. And the classic thing is something called bacterial endotoxin. And this is something that you'll find with E. Coli, salmonella, basically the pathologic bacteria that are a normal part of our body. They They can actually get across and they inflame our immune system. And this is a large part of where chronic inflammation comes from. So our gut microbes play an essential role in maintaining this barrier to protect us.

And just to add that when you eat healthy food like fiber, our beneficial microbes will eat on that fiber and produce chemicals that are then really stimulating our immune system to dampen down any inflammation in the rest of the body. So that's why there's this link between eating good foods and making sure that our immune system is working perfectly, not overreacting, and if anything, can dampen down any of these fires. But it can't do that if it's not getting the right foods for those particular microbes that are very specialized and need real foods to eat. They can't just exist on burgers because those microbes tend to produce pro-inflammatory substances, things that are actually kick up the inflammation more. So that's how our diet starts to play into this delicate balance that Will is talking about.

Is it always one way? So is it basically you start with Whether or not your gut bacteria are good and then it leads to inflammation in the body? Or is there also a chicken and egg where I've got inflammation elsewhere and that then shapes my gut gut microbes? Do we know?

It absolutely is a two-way street. So when you have inflammation, the inflammation does affect your gut microbes. So ultimately, though, the part that we have more command and control over are the choices that we make with diet and lifestyle, those choices ultimately are shaping the environment of the microbes. When you shape the environment of the microbes, then ultimately you are creating a specific microbiome that can create an anti-inflammatory immune system or that is going to promote inflammation in the body.

And we've talked about microbiome and bacteria. I'm conscious there'll be some people joining us at the beginning of the year for whom this might be a bit new. Could you just help to explain a bit what those two terms mean and how that ties back to this idea, I think, of what people are really interested in here, which is, okay, so I want to have the stuff that's going to be reducing my inflammation, But also what's going on with the stuff that's actually increasing my inflammation?

So what we mean by microbes are microorganisms. So that means bacteria. It also means parasites. It means fungie and little viruses. But we tend to call them all the same community. And that community is called the microbiome. And there's good and bad guys in there. And if you're healthy, you'll have a good balance of good guys and relatively small amounts of bad guys. Essentially, they're all like many pharmacies, pumping out generally healthy chemicals. But the bad guys can be sometimes pumping out chemicals that are increasing inflammation, irritating your body. So you want to get that ratio right. And that's where lifestyle comes in.

And is it possible to reduce the inflammation in the gut? So I think you were both describing this pattern where you could have this really inflamed gut and some awful things were happening, well, which we're pretty scary sounding. So is it possible to reduce the inflammation or is this a one-way street?

You can absolutely reduce the inflammation. And the exciting and empowering thing about the gut microbiome is that it is constantly evolving and changing, and it is also extremely forgiving. There's research that was done almost 10 years ago. That was one of the first major papers in the microbiome, where basically they showed that in less than 24 hours after changing your diet, you will start to see those effects take shape within your microbiome. Now, this is not to say that 24 hours is all that it takes to overhaul the microbiome. That would not be true. But the choices that you make today will start to manifest by tomorrow in your microbiome, and it will be a snowball effect. That snowball starts very small. But if you come back and you double down and you keep following with consistency these same patterns, you start to build that snowball, you start to build momentum, and that momentum can be an anti-inflammatory momentum.

And so what happens when the inflammation is reduced? How does that... What happens as a consequence? We've talked a lot about as it going up.

There's two effects. One inside the gut, you'll get a greater number of beneficial microbes rather than pro-inflammatory-loving microbes. And so you get a more helpful set of chemicals being produced, and your immune system will then get back into its normal regulation, and it'll be able to carry on repairing the body and picking up cancers and dealing with aging and really perfecting metabolism so you're not wasting energy and you're feeling healthier and your chemicals going to your brain or improving your mood and your energy. So it's really getting it back into that perfect scenario before, in a way, this false infection hit the body. So the idea is to use restabilizing things. And because your blood isn't having that inflammation anymore, that also acts two ways and again helps the good microbes overcome the bad microbes in your gut. So again, this two-way process, just as well as it happens in the bad way when you get a disease or an infection, the same thing happens when you can improve your diet, then all the rest of it falls into place.

Hi. I want to take a quick break here and tell you about something new we've created, a free guide that will kickstart your journey to better gut health. As we're learning from Tim and Will today, and as our members know through using Zoe, we feed our gut microbiome through the variety of foods we eat. And in return, our microbes give us a wealth of health benefits. They're responsible for so much as we've been learning, from digestion to immune support and even our mental wellbeing. So how can you nurture your gut in the best way? Which food swaps can you try to nourish those good bacteria? What does a high fiber shopping list really look like? Our free Gut Health Guide shares it all. Emails and actionable tips that are designed to put you in control of your gut health. To get yours for free, simply go to zoe. Com/gutguide. You'll also find the link in the show notes. Okay, back to the show. So I'd love, I guess, having talked about how serious inflammation is, how deeply interlinked it is with our gut microbes, these bacteria, to start to talk about, okay, what's the actionable advice?

What can people do? And I think a lot of people listening to this will be saying, okay, that's great. I want to go and make some changes. Tim, maybe you could start by saying, imagine people are thinking about changing what they want to eat. What would you be telling them to do in order to really make a difference here?

Eating a greater diversity of plants, having more color on your plate, having more fermented foods are particularly important. And the fermented food is very interesting because there are now clinical studies showing that people having several portions a day got really big reductions in their inflammatory markers just after a couple of weeks. We don't know the exact mechanism organisms. But we do know that fermented foods are probiotic. So they're live microbes. And there was a US study where they were having lots of different types of microbes, so maybe 30 or 40 different species every day. They seem to have a beneficial effect on the resident microbes in the gut. And that meant they were pushing out helpful anti-inflammatory chemicals and actually drove down and suppressed the immune system system that was previously high. And this was a remarkable result because no one expected this to be quite so dramatic. And there was a much bigger effect just by from fermented food rather than just fiber alone. So this is a real sign that of all those dietary changes we're talking about, whether it's the multiple plants, whether it's the polyphenols in the different color, the fermented food is probably the one that's most specific to inflammation in the immune system.

And it's something I think we haven't really paid nearly enough attention to in the past. So little and often, but I think it's not just having one pot of children's yogurt once a When you're not in a week that's going to do it. You need several portions a day, probably three small portions a day to get these beneficial effects. And at the same time, cutting out some of the negative things in your diet, ultra-processed foods, foods continuing Bad fats that we've talked about a lot. We know that from our own experiments, people having all these highly processed, saturated fats in ready Meals, et cetera, and junk foods, they cause these particular spikes and inflammation. So cutting them out and then giving your gut a rest so it can't spike and so it can repair itself. I think they're the key essential elements that everyone can do if they want to get a nice, even low inflammatory state in them. And people with many chronic diseases, I think, would benefit from this advice, and most of them are not being given it at the moment.

Yeah, it's interesting that it boils down to two essential principles from a dietary perspective: add more plants and add fermented food. And these are two things that we have done throughout human history that we've lost in the last 100 years. And so And restoring that in a way would be restoring a more natural environment for these microbes.

And Will, can you help us understand a bit more about how the plant side of this links through ultimately to this reducing inflammation?

Well, it goes back to a concept that Tim introduced earlier, which is that these microbes have the ability to transform our food. If we were sterile, which we are not, there's never been a sterile human. We've always evolved with these microbes. But if we were sterile, fibre-sterile meaning not that we can't have children, but that there's no...

I just want to make sure I understand this. That's not what-sterile in terms of not having a microbiome.

If we lacked a microbiome, which is not possible. All humans have always had a microbiome. Fiber wouldn't serve the purpose that it does. Because fiber exemplifies our relationship with these microbes. It's mutually beneficial. We consume the fiber. The fiber is actually their food. We don't have the enzymes to break down the fiber and release the nutritional quality from it, but the microbes do. They have actually thousands of enzymes that allow them to go to work, typically in teams, unpacking the fiber and releasing what are called short-chain fatty acids. These short-chain fatty acids, in my For more than 20 years of study in medicine, I can say without any question at all, these are the most anti-inflammatory compounds that I've ever come across. They are responsible. This is how the gut microbes restore our gut barrier. This is also how our gut microbes suppress and control and shape the immune system. It's also how they have an anti-inflammatory effect throughout our entire body, not just in our gut, but even as far as our brain. So the way in which fiber ultimately manifestsates is fiber comes into contact with microbes. Those microbes do us a favor, releasing these short-chain fatty acids.

And in the process of doing that, they're having an anti-inflammatory effect on our body.

So they basically create this magic stuff, these short-chain fatty acids, which I've heard you guys talk a lot about. I have literally no idea really what that means, but that's good stuff. And basically, the point is we can't get it directly just in what we eat.

That's right. It doesn't seem to work when you give it as a supplement. People have tried giving them supplements in clinical trials, and it doesn't work like that. And butyrate is the one that's used most. It also smells like putrifying fish, so you wouldn't really want to have it as a supplement.

So that's not just like... It's not a big part of what... Just be clear, right? Because I don't understand this. Most people don't. It's not like there's loads of these short-chain fatty acids when I eat a banana. It's something that actually you need these bacteria inside us to create out of the regular foods that we might eat.

So they always are the product of the microbes. But there are foods that do contain short-chain fatty acids, such as butyrate. For example, there are dairy products that because the cow has microbes, it produces these short-chain fatty acids. You'll find it in the dairy products. They're in trivial amounts. They're not known to have the same effect on the body. Most likely, what's happening is when you drink them, these fats get absorbed almost instantly into your body without actually getting to where they're supposed to be. This is a very different thing than to consume fiber and have that fiber wiggle its way down through 8 meters of intestines, 25 feet, and arrive into the colon where the microbes are residing, and then be released in that specific location. And I think it's important to bear in mind, it's not just the short-chain fatty acids, it's this process of dietary fiber having this effect in the colon.

So it's like delivering this medicine to just the right place in the right way. And in this case, though, we feed the bacteria, the input to that, and then it actually creates this medicine for us in where it's needed, which is deep in our gut.

That's absolutely right. And this is the This is the most clear example of the millions of years of coevolution that have taken place between humans and microbes. We need them, they need us, and this is how we thrive together.

Yeah. And that's where the analogy of them being mini-pharmaces is really helpful. To produce these wonderful chemicals, you've got to give them the right suppliers. And so that's what our job is, is to make sure they have the right things to make these amazing chemicals for us.

If I was really thinking, I want to reduce this inflammation, so I want to be giving the best food to the bacteria. You talked about fermented foods, but in terms of feeding the bacteria, what are the other key rules that you'd want people to hold on to?

So a diverse range of plants is important because that creates a whole range of diverse different microbes. And the more diverse your set of microbes are, the more different chemicals they can produce together, the less The less waste there is. And interestingly, there's a new study showing that the more diverse your microbes are, the less nutrients there are left for invaders. So if you've got Salmonella or something, it can't take hold in your gut because your community of microbes is absolutely eating all their nutrients. So they will literally starve. Whereas if you haven't got very many because you have a rather limited diet, new invaders like E. Coli or Salmonella will take over. The Different colors are there because they've got these polyphenols in them, which are these defense chemicals, which are a general energy for all your microbes. So in order for them to flourish, they use that as an energy source as well. So regardless of what they're eating, they all like those polyphenols. And then thirdly, you've got the fermented foods, which are these probiotics that have this effect. We still don't exactly understand why they just pass through the gut, stay a few days, and seem to energize your gut microbes to really get our immune system in order and then pass through down the toilet.

So that's why you need to have them regularly. So they're the three things that essentially need to happen.

But one thing, Tim, with the Fermented Foods, the study that you're referring to, which was out of Stanford, and it involved Professor Christopher Garner, who's on the Scientific Advisory Board of Zoe. One of the major findings, in addition to Fermented Foods reducing inflammation, is that the addition of fermented foods in a period of just eight weeks, which is exciting and fascinating, we're able to actually increase the diversity of the microbiome. This is a pattern that we see time and again, because when you look at people who have these inflammatory conditions, specifically the autoimmune diseases, if you look under the hood, their microbiome typically has less gut diversity. So it's quite fascinating that when you move the gut from less diversity diversity to more diversity, you also reduce the inflammation. It's a pattern that we see time and again.

Yeah. I'm constantly told by patients that their doctor has said, your immune system isn't very good, so don't eat fermented foods. And I think we need to be moving away from this rather primitive advice, apart from the very rare individuals who might be having cancer therapy with literally no bone marrow or no white cells, cells. But I think you'd agree, Will, that the vast majority of people would benefit from having more fermented foods in their diet.

I think that that's a myth that really exemplifies how misunderstood fermented foods are and how far we've drifted away from what was a traditional diet.

Well, I think that's really interesting. Now, for people listening, at this point, it feels like only food can reduce inflammation. But, Will, I think there's a bunch of other things that you talk about that you can do in addition.

I think that there's so much that you do, frankly, without even lifting a fork. And that, to me, is quite empowering. Because, for example, if you're a person, I've taken care of many people with Crohn's disease or ulcerative colitis, and these people have the worst food intolerances. It's very hard for them to do some of the things that we're describing here, to say, eat more fiber. I fully acknowledge that as much as I want them to do that, that's not easy for them. Perhaps for them, a place to start is to do these other things. It includes the classics that we always think of. For example, sleep. Sleep is incredibly restorative. People who get a better night's sleep have a healthier gut microbiome. In studies where they take people into a sleep lab and deprive them of sleep, it doesn't take long for you to start to see the effects of deprived sleep on the gut microbiome. It happens very quickly. So sleep and exercise, by the way, many different forms of exercise have different effects on the microbiome. So don't just always do the same thing. Switch up your routine. But I would recommend both cardiovascular exercise and also weight bearing or strength training.

I think both of those are complementary to one another. And then Tim alluded a bit to intermittent fasting or time-restricted eating. And to me, this is an important concept in terms of reducing inflammation and also supporting the gut microbiome. If we could just do one thing, and that would be to have an early dinner. To me, early, it depends on your own personal lifestyle, but that would be before 07:00 PM. And then to say, no food, no alcohol, after dinner. And allow your body a period of time where it's now unwinding, and then you go to bed and you have a truly restorative period of time that's low in inflammation. That is fantastic for the microbiome. And it doesn't take much. We did a study. In that study, the Big If study, we had people doing 14 hours of fasting, which means that they had a 10-hour eating window during the day. And by doing this, We found a number of different benefits, including energy levels increased, better mood, reduced hunger, and I'm personally excited about this one, less bloating. And that's quite simply by making those choices. So once again, there are many different things that we can do that aren't necessarily food that can make us feel better and empower ourselves.

Amazing. I don't think I'm going to be signing up for that. I have to finish all my dinner by 07:00 PM every night. Plan anytime soon, Will. But I like your perfect living.

Well, I think it's more just I want to get people away from the idea of a midnight snack or a nightcap alcohol drink. That's what I want to get people away from.

Amazing. Well, I have to say every night, as I'm I'm finally crashing out after finishing the email and eating dark chocolate while watching TV at about 10:00 PM, I think of the pair of you frowning on my shoulder at my terribly short period of not eating. But there's always something. It's good to have something to aspire to. Are there any final thoughts on this for somebody who's come through this story and is saying, okay, so I'm really convinced. I want to reduce this inflammation. I'm worried, in fact, about how maybe I am on the path towards some long term serious disease, whether it's heart disease or diabetes or whatever. Anything else you'd want to make sure that they were thinking of as we come to the end here?

I would just add that many people are confused. If they went to the Internet and said, I've got inflammation, my doctor said, I've got this new disease, and they might go on social media, whether it's TikTok or Instagram, They'd be confronted with this huge array of weird diets and exclusions, things like alkaline water or potato juice or chlorophyll tablets or When I was doing rheumatology, patients were told they could never have anything with tomatoes or over genes in them ever again. The point is you should be adding things to your diet, not excluding them unless it's ultra-processed. So I think that's the And the message I would have for people is, if you understand the key role your microbes are playing and you're looking to feed more and more of those guys, don't go down the route of these wacky exclusion diets that have no scientific basis on them and are calling themselves anti-inflammatory diets. Anti-inflammatory diet is one that's generally good for your gut microbes. I think that's the message I would leave with.

It's a diet of abundance that ultimately we need in order to be successful, not not restriction. I think just to get back to these essential concepts of fiber and fermented foods. And if we could quite simply add these, because the reality is that the opportunities that will have the biggest impact are the ones that we're not doing. Doing more of what we're currently doing is not going to really make a huge difference. What helps is when we take something that we just aren't doing. We know that 95% of Americans and 90% of British people are inadequate in their fiber consumption. The average amount of fermented food intake in the United States is zero on a daily basis. If we could just increase that a little bit, we would make a huge difference. That's where I would encourage people to start this year. And also, last thing, consistency is extremely important. The choice that you make that you can do on a daily basis, it gets back to the snowball idea. If you can do it and you can come back and do it again tomorrow, it's going to make a much bigger difference than that one thing that you did that one time.

Brilliant. Thank you both. I'm going to try and do a quick summary on quite a complex topic, I thought this week. And please, both of you, keep me honest. So we started off basically explaining what inflammation is. And you both explained that basically if you didn't have the ability to have inflammation, you die really fast of an infection or not being able to cure my broken toe. So short term acute inflammation is a We're built to have that. The problem is that today many of us get us in a situation where the inflammatory response has been switched on and it's never switching off. And for people who are therefore in that inflammatory state for year after year, We'll have this terrifying list of basically every disease that anyone could possibly be worrying about, you're more likely to get it, including, I think, things like cancer that I think I was really shocked here, but also heart disease, things that you don't really think of as being linked to to inflammation at all. That there's a lot of reasons for why that inflammation might be increased, including our environment and what's happening to us as children.

But we talked a lot about how for those of us who are adults listening to this, it's very much shaped by what's going on in terms of what we're eating and by the way that that's affecting our gut microbiome, you talked about this incredibly thin layer, I think, Will, between our body and our microbes and the almost all of our immune system is actually in our gut managing this thing with our bacteria. And that basically the food we eat shapes the bacteria that we have inside our gut shapes, what microbiome we have. And that, sadly, today, the diet that we eat is a diet which is mainly the diet that the bad bacteria wants to eat and not the diet that the good bacteria wants to eat. So we're ending up with the wrong bugs which are actually making our inflammation higher. So that's all very depressing. But the good news, I think, is you're saying, you know what? If you change your diet, you can increase the number of good bacteria in your gut. And actually that will dampen down the inflammation. And I think, Tim, you're saying you could positively reduce, therefore, your risks of diseases and your potentially symptoms from some disease.

Is that correct?

Absolutely, yes.

So that's really exciting. And then you said there's some really simple practical rules. So firstly, what you eat is really central. Eat more plants because plants have the fiber inside them that feed the microbes. And they create then this magic thing called short-chain fatty acids, which I think only Will and Tim understand what they are. But for the rest of us, that's the good stuff that the bacteria make. And so you need to give them the fiber in order to make the good stuff. And there isn't a shortcut. You can't just eat a short-chain fatty acid supplement. It doesn't work. You got to get this fiber to make all of these different bacteria make it. Think about lots of different colors because this other concept, polyphenols, which it means, again, basically lots of foods with these different colors is how I understand it, which again is feeding the microbes that are giving this anti-inflammatory properties. And then separately, I think both Tim and Will, you've got more excited about fermented food over the last few years with this new research And that actually just eating quite a lot of fermented foods, right? You said, Tim, once a week doesn't get you there.

You actually got to eat a few of these. Several portions. It's quite a high bar, which I have to admit, I often don't hit. That could make a difference. And then if people are listening to this, it's not only food that you can do. Interestingly, sleep and exercise can both also reduce your inflammation. And I think we wrapped up with this idea of time-restricted eating. So having long periods periods of the day when you don't eat. So not midnight snacking and then having something at seven in the morning, but having maybe 12 whole hours without eating. Or in fact, if you could get it up to 14 hours, which I never can, then that might be even better. And finally, whatever you do, do not follow any diet that comes about after you click on the words anti-inflammatory diet on the internet, is my takeaway, Tim, because basically you're going to get some totally weird diet where you should exclude things. And I think what I heard was every good diet is good for your gut. It's about adding more things in. And finally, it's about consistency, because the only thing that's relevant here is something you can stick with for years.

So crazy diet, that aren't going to get you there, something that long term supports you.

You got it.

Brilliant. Well, I think everybody has their marching orders, and I think there's something incredibly exciting about this idea that there's things that you can do right now that really can reduce your inflammation and can really improve your health for the long term by basically bringing on all of these microbes to fight in your corner. Wonderful. Thank you very much. Bye bye.

Thanks, everyone.

Bye.

I hope this episode has opened your eyes to how important your gut microbiome is in keeping inflammation in check, and that you've learned something new from Tim and Will. Are you interested in finding out more about your gut microbiome, as I have done? With a Zoe membership, you can understand what's going on in your gut microbiome with the most advanced tests available, and then receive personalized advice and support on how to eat the best foods to support a healthy gut. Zoe can help you feel better now and live healthier in the years to come, backed by real clinical studies. Simply go to zoe. Com/podcast to learn more and get 10% off your membership. Join us next week when I'll be talking to Dr. Andy Galping about how you can improve your fitness to live a long and healthy life. I'm your host, Jonathan Wolf. Zoe Science and Nutrition is produced by Yellow Hewins Martin, Richard Willen, and Tilly Fultfoot. As always, the Zoe Science and Nutrition podcast is not medical advice. It's for general informational purposes only. If you have any medical concerns, please consult your doctor. See you next time.