Dr James Kinross: I think trying to interpret them at home is just impossible, right? And most of these consumer tests, you get 80 pages of results, right? And it's just bullshit. It's bullshit. And I can't understand it, and I'm a microbiome scientist. So how the hell you're going to do it, I don't know, right? And I think it's overwhelming. And I think unless it's interpreted by someone who knows what they're doing in a clinical context, I think it's meaningless.
Dr Rupy: Welcome to The Doctor's Kitchen podcast. The show about food, lifestyle, medicine and how to improve your health today. I'm Dr Rupy, your host. I'm a medical doctor, I study nutrition and I'm a firm believer in the power of food and lifestyle as medicine. Join me and my expert guests while we discuss the multiple determinants of what allows you to lead your best life. We have world-leading microbiome scientist and surgeon with over two decades of experience, Dr James Kinross on the podcast today talking about everything to do with the gut. This is a massive topic and gosh, I could have spoken to James for so much longer than we did. We're definitely going to have to do a part two. In this episode, we talk specifically about some signs that your poop is unhealthy, as well as some of James's favourite foods and nutrition strategies to improve the gut. I shouldn't have put those two together. We also talk about why we need to think more like conservationists. I really like this concept that James is pioneering about recognising that our guts are essentially being radically altered and destroyed by our environment. And that's not just from the food choices, but also from medication pressures as well as pollutants in our environment as well. We talk specifically about functional gut disorders with an emphasis on IBS, which James will explain is not the best description of what IBS actually is, and why trauma, stress and childhood health are some of the first things that James will ask about in clinic before ever reaching for a prescription pad, if at all. We also talk about the estrobolome, the interaction of hormones and our microbes, as well as testosterone, whether our gut can actually dictate our food choices and if we can do anything to change that as well. And also, I get James's opinions on probiotics, gut health tests and their validity overall, as well as the relationship between our gut, our brain, including things like neurodiversity, autism spectrum disorders and dementia as well. James is a senior lecturer in colorectal surgery and a consultant at Imperial College. He also leads the team defining how the microbiome causes cancer and other chronic diseases of the gut. And his book, Dark Matter, his first book, is an incredible read. I genuinely mean it's one of the best books I've read on the gut microbiota. It is phenomenally well researched and it's written with such expertise, not just from a knowledge point of view, but also the way it's written. It certainly takes you on a journey and there are some really heartwarming elements of this book that I think everyone will enjoy. So I highly, highly recommend you check out Dark Matter, buy it in all good book stores and online as well. And remember, you can watch the podcast on YouTube, just click the button in your show notes on your podcast player and you'll be able to see our smiling faces, me and James in the Doctor's Kitchen studio. Remember, the Doctor's Kitchen app gives you full access to all of our recipes. If you've ever been sat or stood in front of your fridge, I should say, and just wondering, what should I do with this red pepper or this courgette or this onion? You can go on the Doctor's Kitchen app and type in your food ingredient and it will come up with a ton of recipes that are suited to your preferences, your dietaries, your health goals. We've just added menopause and gut health as a health goal as well. Check out the Doctor's Kitchen app. There's a free trial. You can download it on Apple, Google, and you can also get it on desktops and iPads and try that 14 free 14-day free trial. I'm sure you're going to love it. 1500 people have rated it five star and above across Google and Apple. Go check it out. It's a it's a wonderful piece of tech that I'm super proud to have brought to market. For now, this is my podcast with the incredible James Kinross. I really hope you're going to enjoy it. James, so lovely to have you in the studio. I really appreciate you taking the time to talk to us about the epic book that is Dark Matter. It's a phenomenal book.
Dr James Kinross: Oh, that's so kind of you. Thank you very much.
Dr Rupy: Of course, of course. Talk to us a bit about your day-to-day. So you're a colorectal surgeon, you've also done a lot of research, obviously for the book and prior to that.
Dr James Kinross: I have a slightly unusual existence. So, you're right. I mean, I work in the NHS, my day job is removing people's bowels, and I'm not quite sure how that happened, but my specialist area is bowel cancer really, although I treat, you know, lots of benign conditions of the gut and I'm a robotic surgeon, so I use fancy bits of technology to try and do that operation really safely, really precisely. But I'm a scientist, so I'm a clinical scientist and I did a PhD in the microbiome back in the day and I have a research group and I'm based at Imperial College in London and we study how microbes in the gut cause chronic diseases like cancer. And we're interested in how you can engineer the microbiome as a therapy for cancer. And probably most importantly for you and for this conversation, how you can prevent cancer by changing the microbiome. And of course, diet and nutrition is a really key part of that.
Dr Rupy: Yeah, yeah. Let's talk about that. Let's just go right into it. So in terms of preventing cancer, why don't we talk about the stats of cancer today and with a particular focus on on bowel cancer?
Dr James Kinross: So, so bowel cancer is unfortunately really, really common. It's the second commonest cause of cancer-related death worldwide. And we have about 40,000 cases of bowel cancer in the UK each year. Many people get confused by what bowel cancer is and it isn't. So what we're really talking about is cancer in the colon, which is also called the large bowel or the rectum. And what's troubling to me as a surgeon about bowel cancer is that although we've got very effective prevention strategies in the United Kingdom, is that the incidence of bowel cancer in young people is climbing. So if you're under the age of 50 or you're under the age of 40, your risk of having bowel cancer is about four times that of someone that was born in the 1950s or the 1960s. And the incidence is changing really dramatically in young people. So part of what we're trying to do in my research group is to understand why that is happening. Like why have we had such a dramatic population shift over over, you know, a relatively short period of time.
Dr Rupy: Yeah. And what are some of the things that you've come across that could explain that rapid rise? And and just to be clear, so it's it's four times more likely than it was a generation ago. What are the absolute numbers in terms of the under 50 and under 40 group?
Dr James Kinross: Um, so you mean in terms of incidence? Well, it's it's it's difficult to say because a lot of that data comes from international international databases like the US databases. But it is a global a global phenomenon. Um, and um, we're seeing that, we're seeing that rise predominate in westernised, urbanised environments. And the causes for that are multifactorial. There's no one single driver. But it is kind of what you think it probably is, which is changes in nutrition, diet and environmental exposures because the gut really is a giant sensing organ and it's just dealing with the antigen load that it has to experience every day on a day-to-day basis. Now, the answer to your question, why is that change happening is quite nuanced. And I've got a theory as to why it is. And it obviously has something to do with the microbiome, in my view, because that's kind of obvious. But um, to explain that, you have to understand what the microbiome is and what it isn't. And you have to understand that um, it's beyond not just about what we're eating, there's other forces at play here. So very simply, the microbiome is a collection of microscopic organisms and all the things that they need to sustain themselves within a niche. So you've got lots of microbiomes within your body. You've got them on your skin, in your lungs, in, you know, um, in your urogenital tract, but you also have them in your gut. And your gut is a long tube that runs from your mouth to your bottom. And the majority of them live in the colon. And um, there are two key things you need to understand about the microbiome beyond that. The first is is that it has a fundamental evolutionary partnership. So the microbes on this planet were here long before we got here, and they'll be here long after we're gone. And all of our organs and our organ systems have developed in partnership with them. So they're fundamental to their normal functioning and growth and development. And the second thing is that the microbiome changes with us along our time course. So the microbes that you're born with are not the same ones that you die with, and they have different sets of functions that sustain our health at different life stages. So if you want to understand a chronic disease like cancer, what you have to understand is the role or the interaction of the microbiome and all of the things that you come into contact with in your life, like the foods you eat, the city you live in, the pollutants that you're that you're exposed to, and how those interactions occur over a life course, but also over generations. And what I think we're seeing is a fundamental loss or change in the microbiome over, you know, 40 or 50 years, which is generational. It's passed from generation to generation to generation. And then that microbiome is simply not equipped to deal with a modern lifestyle, a modern uh westernized diet. And then the consequences of that are are cancer.
Dr Rupy: Okay. So this loss of our microbial diversity is in part one of the reasons why we're seeing a higher incidence of cancer potentially. Is that about?
Dr James Kinross: So the way the way I think about it, the way I conceptualize it is that I think we are experiencing an internal climate crisis. I think it's that profound, it's that fundamental. And um, we know because we can measure microbes over time, we know that we're losing microbes. But in like in any other ecosystem, whether it's oceanic or whether it's a forest or where it's any other kind of planetary ecosystem, when you have a climate crisis, there are losers and there are winners, right? So you might lose critical microbes that are important for the maintenance of health, but you might gain microbes which are perhaps harmful or not so good for your health. And microbes are really tenacious and they're really amazing at surviving and they're really adaptable. So they they don't hang about. They're mutating, they're sharing genes and they're doing whatever they've got to do to survive in this really challenging environment that we've created for them. And so, yeah, I think it's an internal climate crisis. Therefore, prevention strategies can't simply be a single strategy. They have to be kind of systems level strategies to try and fight that in the same way that you need to fight a planetary climate crisis. If you're trying to deal with an internal one, you need a similar strategy. And the other thing that I would say is is that the conversation that we're starting with today is focusing on cancer and I I get it. Um, what's interesting about cancer is that of course, if you lived 100 years ago, you were kind of unlikely to die from cancer. Like you might, but you had to be pretty lucky basically because the chances are were that you were going to die from a pathogen. Like a bad bug was going to get you and you were going to die of pneumonia or tuberculosis or a cholera or gastrointestinal infection. And if that didn't get you, it might be it might be another pathogen. Uh, and if you lived into your 50s and 60s and 70s, well, then you might be lucky enough to get it. But of course, we've eradicated many common pathogens. And my hypothesis is that in the pursuit of the eradication of pathogens, what we have inadvertently done is created that internal climate crisis. And what we've been left with is a rising burden of, well, a pandemic, right, of non-communicable disease, cancer just being one. So if you look at the changing epidemiology of diseases globally over the last 50 or 70 years, what you see actually is a dramatic change in the things that not just kill us, but leave us with a really poor quality of life. So the things that kill us are cardiovascular disease, it's stroke, it's heart attack, it's obesity, it's diabetes, it's cancer. But also a rising pandemic of immune mediated diseases. So problems with our immune system, right? So that might be inflammatory bowel disease, rheumatoid arthritis, but it also might be different bits of the immune system. So allergies, asthma, atopy, like half of Europe has an allergy. How did that happen, right? So what I'm arguing is is that a major explanation for that might be this internal climate crisis. And the reason for that is that microbes or your microbiome is a very important determinant of how your immune system learns to deal with the world around it. And if that immune system is not set up correctly in early life, and there's a generational loss in the ability of that immune system to function, the result is a pandemic of immune mediated disease.
Dr Rupy: So we have a situation where the incidence of bowel cancer is increasing, the number of people with autoimmune conditions, atopy, allergy, etc, is increasing. What do you suggest we should be thinking about with regards to pragmatic changes to our day-to-day that could mitigate or offset some of those issues with the digestive tract?
Dr James Kinross: So, so I think there's lots of really important things that you can do to change that. And many of your podcasts, you know, are explaining this. So the good news is is that nutrition and diet is a really important way that you can change your risk. And we've known this for years. We've known this for decades that a plant-based high fiber diet that reduces um animal fats, uh ultra-processed foods, refined sugars, significantly reduces your risk, not just of bowel cancer, of cardiovascular disease, diabetes, dementia, like a whole number of different diseases, right? What I would call diseases of progress. Uh, what I mean by diseases of progress is is that these chronic diseases no longer kill us. I mean, they do, obviously, but generally what they leave us is leave us with is a poor quality of life. So we live very much longer nowadays, but our quality of life is deteriorating because these diseases are very disabling and they're very expensive and very, you know, difficult to look after in in healthcare systems. So coming back to your question, nutrition and diet, really, really important. But your question is actually quite a complicated one to answer because um, nutrition and diet doesn't solve the climate crisis. What you have to understand is what are the fundamental things that are destroying that ecology and and how do we prevent the destruction happening in the first place? And sometimes the solutions are pragmatic and practical, and we'll get on to some of them, I'm sure in this conversation. But sometimes they're about policy, they're about, they're about how you um, build a fairer society which actually, you know, we all take collective responsibility for in the same way that you guys, I'm sure recycle your plastics and you recycle your, you know, your household waste. Like we take collective responsibility. So I think what I'm trying to do is to try and bring this conversation into the mainstream and try to rethink a little bit about what health really is and the role that microbes really have in it. And to think about microbial conservationism as a form of health prevention, disease prevention and health in in and of itself. You want a healthy planet, you need a healthy rainforest. You want a healthy body, you need a healthy rainforest of microbes in your gut. It's pretty much that simple.
Dr Rupy: Okay. We're going to get to some of those other strategies, I think from a societal point of view in a bit. I'm going to I'm going to ask you a left field question. What are some of the signs that your poop isn't healthy?
Dr James Kinross: That is left field. And I will answer it because do you know what? It's like amazing, like people love talking about this. Uh, it's amazing. So, I think the interesting thing is that everybody's gut is kind of variable. And uh, like it's normal for some people to go every three days and it's normal for others to go three times a day. What's most important is that if you notice a change in the frequency or habit of your bowel function and that change is sustained for more than six weeks, that you seek help. Right? That's number one. Number two is
Dr Rupy: And so that change, is that regularity, consistency, all of the above?
Dr James Kinross: So it could be all of the above. So it might be things that worry me as a doctor are if you say, actually, I'm usually, you know, pretty regular and now I'm going much, much more frequently. So for example, I'm going three, four, five, six times a day when I would usually go once a day. Or if you're normally pretty soft and now you're loose, or if you were constipated and you're loose, or if you've gone the other way. There are obviously other things that we worry about. So if you're passing blood, you need to see your doctor. Uh, and if you're passing dark blood, you really need to see your doctor. So the the difference is that, you know, bright red blood can sometimes be from benign causes like hemorrhoids, but you still need to get it checked out, right? Dark blood means that maybe something's bleeding a bit higher up the system and we really need to know what's going on.
Dr Rupy: Okay. Any other changes or any any other signs that your your poop could be unhealthy?
Dr James Kinross: I think those are the main ones.
Dr Rupy: Okay, fine. What about if it's intermittent changes? So, uh, I've had a change, it lasted about a week, and then I'm back to normal. And then a couple of months later, I have another change and then I'm back to normal. What are the other things that you might be asking someone in front of you who's presenting with that sort of irregularity but over a longer time period?
Dr James Kinross: So, um, I I mean the top line message here is if you're worried, go and see your doctor and just don't be embarrassed about it because your doctor really wants to talk to you about it. And um, um, it's much, much better to get help than to sit at home and worry. But to answer your question, it it really depends on the age of the person I'm talking to, the gender or sex of the person I'm speaking to and the context. For some broad broad questions, things that I want to know about are number one, are you having any other symptoms with these changes? So for example, are you having abdominal pain? Are you having bloating? Are you having um, are you noticing that particular things are triggering those symptoms? So that might be particular change in your nutrition or diet or it might be something different. Maybe you've been put on medicines. And quite often there is a there is a driver for that which can be explained through through through those things. I'm interested in whether you're feeling sick, whether you're vomiting. Is there something else happening in your gut here that we really need to know about? I want to know about your risk of infections because that might be quite a common cause. But also your family history. Is there something else here that is perhaps suggestive of a problem that might be chronic, that might be familiar that we could that we could look at.
Dr Rupy: Yeah, okay. Let's say you've been to your doctor, they've examined you, they've excluded any red flags, um, they don't think there's a cancer, they don't think there's a growth, um, and they point it to lifestyle. They think it's probably something to do with your lifestyle. What are some of the lifestyle changes that you would say people need to lean into more to prevent these these issues with the digestive tract?
Dr James Kinross: I don't think there's a one size fits all answer to that question. And what I've learned in my time over the years is that you have to treat the individual and make an individual kind of assessment. The first thing I do in that situation with that individual is I take them right back in time. So actually with that individual, what I really want to know about, and this is really answering your former question, but in that very particular scenario, is I want to know what their childhood was like. I'm not Freudian, but what I want to know is was their gut functioning when they were a kid normally? Were they constipated? Were they having functional gut problems? I want to know about their antibiotic history. I want to know about whether they were an an allergy kid. Did they have eczema? Did they have asthma? Um, were they were they um, were they someone that was always in and out of hospital with kind of griping tummy pains? And and and these are really important questions to understand because they tell us about how the gut was set up in early life and whether or not there's been some some damage to the microbiome or damage to the gut in early life that actually we need to go back and unpick because unless we unpick that, we can't really make them better. The second thing I really want to know about is their mental health. So in patients who have IBS, and we can talk about IBS in a bit more detail, but it's a terrible, terrible name for a terrible, terrible condition because IBS is not irritable, it's bloody awful. It's not really a problem of the bowel, it's a problem of neuroimmunobiology. It's a it's a problem of how the immune system interacts with the gut nervous system. So it's really about gut brain. Uh, and it's not really a syndrome, right? It's it's not. Uh, a syndrome implies it's a collection of symptoms for one condition and IBS is really it's a lots of different types of gut brain disorders. So in that instance, I want to know about mental health because quite often there's an underlying history of trauma. So or there's a history of eating disorders or there's a history of sometimes um, neurodiversity that's never really been properly detected. And until you address those things, you can't really understand what's driving the condition. In women and and girls, I really want to know about their menstrual history and I really want to know about the cyclical nature of their pain because very often they're connected and most doctors just don't ask about it or they just don't think to ask about it. And and and quite often women will say to me, yeah, around the time of my period, symptoms get much better or they'll say they get much worse. Or they will say at the time of puberty, things just really kicked off and that was kind of a real problem. And that's very important to know because you can do something about it. Like that's a lever for making change. I really want to know about their nutritional and dietary history. So I then go into a lot of detail about what they've done. And what you find quite often in these patients is that they've all tried really extreme nutritional interventions because they've suffered so terribly, right? So they've excluded a whole bunch of stuff from their diet. Maybe they've got really unhealthy attitudes towards foods because they spend a bit too much time on social media and they're it there's usually quite a lot of damage that has been done that has to be unpicked in a really in a really sort of considered and careful way. And that means I work with a big, I'm really lucky. I've got some amazing dietitians that I work with and we have a big team of us and we kind of bring in all these people to to try and help. And then what I will say is, look, the solution to kind of functional gut brain disorders like that is not medicines, it's almost never medicines. Sometimes medicines help and there's a role for medicines, but quite often it's about lifestyle, behaviour, and it's about kind of pulling all of those levers that I was telling you about before. So it's sometimes it might be things like um, psychotherapy, it might be hypnotherapy, but again, you have to understand that those things are what I would call like marginal gains impacts. They're not going to transform everything, but it's just going to give you another little strategy for coping with it. It will almost certainly be nutritional and dietary, number one. And then it will also be things like exercise and physical activity. It might be contraceptive pills or hormone therapy in post-menopausal women. And it might be sometimes something very, very, very specific. So, um, I increasingly beyond doing conventional diagnostic tests, which we would do, I will sequence out the microbiome. I will have a look at microbes and we'll try and think about strategies that are quite focused and targeted to the microbiome to try and make a difference.
Dr Rupy: Yeah. In terms of those investigations looking at microbes, what are some of those tests that you you would do if you had, you know, all the resources available to you?
Dr James Kinross: So, so I think microbiome testing is the wild west, right? And I think there's a lot of really terrible direct to consumer tests which are expensive and you just shouldn't waste your money on. And the reason they're not very good is that the sequencing technology, so what I mean by that is that the way microbiome tests work is that normally what they do is they look for particular genes within these bacteria and then they compare those genes to a database and they work out, oh, do you have this bacteria or do you not have this bacteria? And the problem is is that that test is not very accurate. So it doesn't really tell you which very specific species or strain of bacteria you've got in there. The the maths they do on that test is very, very variable. And what that means is that you could you and I could, um, sorry, I could do the test with three different companies and get three different results. And and there may be no consistency in the analysis between you and I. So what I do is I use a I use quite a particular kind of product and I use something which I know is validated that uses a deeper level of sequencing that I can be really sure gives me the information that I need.
Dr Rupy: Can you tell us what that test is?
Dr James Kinross: Uh, yeah, I can. Uh, it's a I use, well, if you go to www.gutid.com.
Dr Rupy: Gut ID. Okay.
Dr James Kinross: Right. Um, and but but I think those tests, like, should be used in a clinical context. I think trying to interpret them at home is just impossible, right? And most of these consumer tests, you get 80 pages of results and it's just bullshit. It's bullshit. And I can't understand it and I'm a microbiome scientist. So how the hell you're going to do it, I don't know. And I think it's overwhelming. And I think unless unless it's interpreted by someone who knows what they're doing in a clinical context, I think it's meaningless. Um, and um, and again, like, you have to understand what the test tells you and what it doesn't tell you. It doesn't tell you quite a lot of stuff. Like these tests only tell you about bacteria, and there's lots of other components of your microbiome that are very important. And it doesn't also tell you about function. It's not telling you necessarily what these bugs are doing and how they're interacting with your gut. So the way I look at it is that it's a it's a piece in the puzzle. It's not a panacea, it's not the whole solution, but it's something that many clinicians overlook and don't analyze. And if you've got 100 trillion bacteria in your gut, which is like 30 million genes, which is like, you know, 300 times your human genome, like, why do you not want to know about that? Like you should want to know about that.
Dr Rupy: Absolutely. Yeah. And I find it quite helpful.
Dr James Kinross: Yeah.
Dr Rupy: And and okay, so with regards to the sequencing or the the different sort of microbial tests that you can find online, is the reason why they might yield different results because they're using different sequencing methods?
Dr James Kinross: Correct. But there's more variance than that. So the sampling technique is super important. So like without wishing to be too crass, like a poo is about 60% bacteria, right? And these bacteria when you have a poo, they don't just, you know, stop working, they keep fermenting and metabolizing and changing. So a poo, like it's a living thing and it just keeps it keeps it keeps altering and changing. So and the other thing is, uh, I don't quite know how my life came to this, but uh, like, you know, the the bacteria on the outside of a fecal specimen are not the same as the bacteria on the inside. So there's variance throughout the sample. And and again, of course, the other thing is that a fecal specimen is only the output of a system. It's not necessarily telling you what's happening higher up the tube, right? So it's not really telling you necessarily what's happening in the duodenum or the small bowel. It's really just the output. You can derive insights from that, but you've just got to be careful about what it can and can't tell you. So there is variance in the sampling technique, there's variance in the sample processing, there's variance in the sequencing technology, and there's variance in the analysis they perform on it. And and and I think the big problem is that the information that is then given to the consumer is usually really generic and not that helpful. So actually you need precision and that's why I use that test because it just gives me that precision.
Dr Rupy: Do you think doctors, and I'm thinking with my sort of GP hat on here, are equipped enough, even if they were able to go and find a patient that's willing to spend the extra money on a gut test to be able to actually interpret it for that individual? Because I mean, certainly during my GP training, we weren't taught any about that.
Dr James Kinross: 100% not. No, no way. And and that is really unfair on doctors because they just I I mean, I mean, I don't need to tell you this, I'm preaching completely to converted, but I don't think they know enough about dietetics or nutrition, let alone microbiome. I think that is changing. And I think I think this fits into the broader revolution in kind of computational sciences, AI sciences, and I think the tools to interpret them are coming online. But I think there's a whole bunch of education that needs to happen. The other thing is I don't it's not just that doctors are not taught about the microbiome or necessarily how to interpret microbiome tests, they're not taught how to use microbiome tests. So for me, a microbiome test, um, because the one thing that we've learned about microbiome science over the last 20 years is that your microbiome and my microbiome are completely different. They're like a fingerprint. Like at a species level, we might share 10% of the same species. Um, and therefore making assumptions is quite difficult about the health of your microbiome versus the health of mine. And and so longitudinal analysis is really, really important. What you actually really want to do is sequence your microbiome when you're healthy, when you're well, because then you kind of know what your baseline really should be. So when you get sick, actually, you know what's changed and what should be there and what what shouldn't be there. And it's as much about that, right? So it might be like as doctors, we are conditioned to think in a 19th century way about human biology. Like still, it doesn't it just completely blows my mind. So we're taught to think like Louis Pasteur did about germ theory, which is that all microbes are bad. So typically when you're looking at a test, you're saying, well, are there pathogens there that shouldn't be there? Your brain isn't going, what's missing? It's not going, hang on a minute, what have we lost here? And um, what mutualists should this patient be having in their gut or in their sample to promote health? And how do I sustain them and grow them back? Um, and and how do you do that over time? So to me, the microbiome is most useful, microbiome analysis is most useful in that capacity. Sometimes it's useful for detecting pathogens and bad actors, but most of the time it's about, okay, how do I think about this patient's ecology? And how do I get their ecology back to a state where it's doing all of the things that that person needs for it to do to be well and to be happy.
Dr Rupy: Yeah. So in my mind, there is uh a role for mapping out what bugs are there, including, you know, viruses and and bacteria, but right now we're just talking about bacteria. But then also figuring out what the function of those are. So what the outputs are, what the metabolites are. Are there tests that actually demonstrate that end of the spectrum as well? Is that part of the test that you currently use or?
Dr James Kinross: So so there are, um, and they are slowly coming into the clinical domain, but we've been using them experimentally for a long time. So, so bugs produce small molecules and we can measure those small molecules, we call those metabolites, right? Um, and they also produce proteins and we can measure those. So we can do that in a very targeted, quantitative way, and we can do that in a really species or strain specific way. Um, but we can also measure the consequences of bugs interacting with the gut. That's much more difficult to do. So we sometimes, for example, would measure the epigenetics of that. So how bacteria change the expression of genes. Um, the problem with that is that many of those techniques are still experimental. In fact, I would argue that the majority of microbiome sequencing technologies haven't really been validated. They haven't been standardized. So we don't have any quality assurance that says, okay, if I'm using this test, I know that this test has been applied in a very robust and standard way and that I'm going to get the same data every single time. And for these other tests, it's even less clear. So at the moment, there's a big debate about what are the optimum ways to measure the microbiome in routine clinical practice. And we're still quite a long way from actually having it there in the way that we are, for example, with measuring the human genome. It's taken us a long time to get to a point where we can routinely perform human genetics and we're about 10 years behind in the microbiome science, I think. So we've still got a bit more to do.
Dr Rupy: With a focus on functional gut disorders and IBS, respectful that it's a terrible name, uh, and also respecting the fact that a lot of what you see is actually a result of unnecessary restriction from, you know, misinformation online. What are some of the worst foods that you think people should be uh cautious of in terms of how they may exacerbate an underlying disorder?
Dr James Kinross: I think to answer that question, you have to think about it in two ways. The first is, what foods do we think might cause the problem in the first place? And then what foods are going to exacerbate it or keep you in that cycle once you're there. Okay. Um, and that's an interesting question where there's a lot of debate, particularly around causation. So I think what we can quite comfortably say is a western diet is really bad news for your gut and your gut development. You might argue what a western diet is, but broadly I conceptualize it as like a high animal fat, high um, animal protein, low plant-based fiber, low um, you know, uh, um, well, low plant-based foods, but you would probably throw ultra-processed foods into that mix and you would throw refined sugars into that mix. I'd actually throw alcohol into that mix. Um, and um, like we've known this for decades, right? We know that this is really bad. So in my research group, what we do is we are trying to study um, how that impacts gut function and gut evolution and gut development. And we've done some quite interesting, well, I think they're interesting, but I'm biased, right? Uh, we've done some studies looking at ethnic groups that are at very high risk for gut problems and those at very low risk. So we looked at African-American males, and then we looked at sub-Saharan African rural uh, uh, people who have very high volumes of fiber in their diet, like 50 grams of fiber a day, almost no animal fat, almost no protein, animal protein. And then we crossed over their diets. And we just gave the Americans the African diet and the African the American's diet. And we watched what happened. And the transformation is astonishing. What's so interesting about the the the transformation is it comes back to our previous discussion, is that the transformation is not necessarily in wholesale changes in the ecology of the gut, but um, dramatic changes in the functions of those microbes. They change, it's like night and day. And and the really good news about that is you can change your diet and you can have an impact very, very quickly within two weeks. And it's completely uh reciprocal that change. So what I'm interested in though is perhaps maybe we need to go even further back in time. So I think that many of these functional gut problems don't happen in adulthood. They're not caused in adulthood by eating, you know, fast food. I think what's happening is that actually it's the it's it's right at the moment of, I would actually argue it's the moment of conception. And I would argue that the that the maternal diet whilst you're gestating is is probably the most important nutritional and dietary driver of long-term gut functional changes. Wow, okay. I'm I'm a radical on this, right? But certainly, but certainly, if it's not the maternal diet, it's the diet that infants experience certainly in the first three to five years of life. Yeah, okay. And and my rationale for saying that is twofold. Number one is that the maternal microbiome, so the microbes inside the gestating mother's gut, they the way I often describe it is they sing to the gestating infant, right? So we know that um, I this is even more controversial, right? There's this theory that the gestating infant is sterile. Like there's no microbes in a gestating infant. They can't cross the placenta, therefore it's sterile. May not be it turns out, but that's more controversial. But certainly what is happening is that the gestating mother's gut is producing lots and lots and lots of small molecules like metabolites that we were talking about. And those will happily get to the infant and they do have a very important role in influencing organ development in that infant, right? And the development of that infant's immune system. And the really good example of that would be something called short chain fatty acids, which is a byproduct of plant fiber metabolism. So if mum has a westernized diet, the infant simply can't get the metabolites it needs to have normal organ development. And we know that changes their risk of obesity and chronic health diseases long term, right? We know that from really elegant studies. But we also know that the gestating so the infant when they're born, they're born with a gut that's, you know, more or less, you know, sterile. There's not a lot of bugs in there. And it blooms, like it comes to life, like very, very quickly through breastfeeding. And then as that infant explores the world, it becomes more sophisticated, more nuanced, it becomes richer, its diversity changes. And by about the age of five, it reaches an adult construct. Not necessarily a microbiome with an adult set of functions, but the ecology is kind of set, it's kind of locked in. And so what I'm saying to you is is that if you if that if that um, if that process is really badly damaged, through nutrition or diet that's not effective, or through other factors which I'm sure we're going to talk about in a second, actually what happens is the gut is just not set up to cope. And that's why when I'm speaking to patients like we were talking about, I want to know what happened in those formative years. And more often than not what you find is you'll say, I'll say to I'll say to patients, hey, were you an earache kid? And they'll go, yeah, I was an earache kid or I had tonsillitis all of the time. And I was always taking that yellowy kind of medicine, you know, which is always the penicillin. And what you find is that in early life, they were just getting hammered with antibiotics. And so what I think is much, you know, I know diet and nutrition is important. I don't want to take away from it, but actually what I'm really interested in is the destruction we do to our internal ecology in infancy and in early life and the long-term consequences for that, which will be lifelong and which never get unpicked and which never get understood. And the problem if about not knowing it is that when you go to see a doctor, the doctor unknowingly will then just keep you in that cycle because they don't have any other solutions and so they'll just keep giving you the antibiotics. They keep giving you the medicine, which keeps causing damage to the microbiome, which just takes you further and further and further away. And then what happens is they end up in my clinic, desperate, going, I just don't know what to do anymore. And the strategy, the solution is to think like a conservationist. It's to go, hang on, let's stop the cycle and how do we grow back a lovely, luscious green ecosystem like your lovely, right? Uh, that has the functions that it needs.
Dr Rupy: Yeah, yeah. You talked about this concept uh of antibiotic scarring in the book as well. Is this what you're referring to with these multiple insults to the the gut?
Dr James Kinross: So there was a group in Washington that did a study that I find that really influenced me. And it was a study that they did looking at patients, healthy individuals, and they gave them a single dose of an antibiotic called azithromycin, which is quite a strong antibiotic. Uh, and what they did was they then followed those patients over a period of about two years looking at the impact on their microbiome. And then they compared those patients to um, some intensive care patients that have been really, really sick on massive doses of antibiotics. And what they found was is that some of those patients given azithromycin were very, very susceptible to damage. And in a proportion, their microbiomes never grew back. So they just one dose of antibiotic, that was it. Their microbiome was forever changed. And um, in fact, it was so badly damaged, it resembled the microbiome of a patient that had been in intensive care. And it wasn't just that the kind of the rainforest of microbes was burnt to the ground, it was that what grew back just didn't have the same function. So it wasn't producing all of those same molecules that you need to sustain your health and and they referred to it as microbiome scarring. And so that so that's where I think about it. I think imagine like a rainforest just being torched. It's that, that's how I conceptualize it. And what we know is that when you do that to the developing gut, and we know this again from very good longitudinal studies done in Finland and in and done in in Scandinavia, and we know this from really good, very large scale epidemiological studies. When you give antibiotics to infants, you fundamentally change their risk of obesity, you fundamentally change their risk of diabetes, you change their risk of um, inflammatory bowel disease, you change their risk of actually, you change their risk of bowel cancer. Right? You change the likelihood that you're going to get polyps, which are pre-cancerous lesions in your bowel. And we also think it has a role in brain development, although that's a bit more controversial. And what we know is that the more antibiotics you have and in the larger dose, the stronger that effect is. So if you've had antibiotics, you know, as a child, your risk of getting irritable bowel syndrome is three times that of someone who hasn't. It doesn't mean that nutrition and diet is still not important. It is important, but I'm increasingly of the opinion that the destruction that we create on our internal ecology through the misuse of antibiotics might be more important. So to give you a sense of scale, like we prescribe 38 billion daily doses of antibiotics each year globally. 38 billion, right? Oh my gosh. Uh, like it's a lot. And and and and the majority of those antibiotics are not actually being used in in the West, they're used being being used in China and India where it's just much easier to give the antibiotic rather than, you know, think about the consequences of it. And the majority of these antibiotics have been given to our kids. And um, what really troubles me about this is that we've known for a very long time with antibiotics. In fact, if you go back to the 1940s when antibiotics were first really being widely used, which was at the end of the Second World War, the United Kingdom, well, the globe, the world, we we had a starving population. We had, you know, food stamps. We couldn't feed our people. And the UK was in crisis actually. But we had this new amazing medicine. And so what farmers did was they quite quickly started giving antibiotics to their animals because that was really good for husbandry because they were less likely to die, right? But they also noticed that they got fatter quicker. And you could get a chicken to market weight, you know, in half or a third of the time. So what happened was is that antibiotics were then systematically misused, um, not by farmers, but they were missold by pharma, basically. Uh, and encouraged by governments because we had to feed a growing population. And um, the consequences of that are twofold. Number one is that 80% of all antibiotics today are actually used in farming and food production. So diet and nutrition is super important because the foods that we consume are grown largely thanks to antibiotics. And antibiotics are in our soil, they're in our oceans, they are everywhere, right? You can't you can't escape them. So we'll talk about the soil microbiome, I'm sure in a minute, but the other consequence and what I'm arguing for is that basically we're treating our children like battery chickens from the 1940s and wondering why they're obese. You trash the microbiome in early life, you inflame the gut, you promote insulin resistance, and then you just feed them a westernized diet, high in animal fats, low in fiber, and then we wonder why they're obese. Well, of course, you know, but unfortunately it's not just obesity, it's all the other stuff that comes with it, right? Because of course, the microbiome is important in brain development, it's important in cardiovascular, it's just it's linked to everything. And and therefore you've got a big old problem. Or we have one anyway.
Dr Rupy: Yeah, yeah. It's a it's a collective problem. I I want to I want to bring us back to to the functional gut disorders because we're all inherently lazy, right? Uh, and I think people are probably listening to this and you've articulated so well a lot of what people are suffering with. They try loads of things online, they go to their GP, they go and see a number of different specialists for all the different ailments that they have, and they end up in your clinic, just don't know what to do. And what you what you talked about with regards to uh figuring out what kind of childhood uh issues you had, the courses of antibiotics, where you're an earache kid. I was an earache kid as a tonsillitis kid. You're speaking to me as well. Um, stress, trauma, etc. Is there an 80-20 here? What is there uh a an area where you're like, okay, 80% of the issues I think are down to this, and it doesn't necessarily be just be diet, it could be stress, it could be trauma, whatever. But is there an 80-20 rule there or is it literally on an individual basis, everyone's got completely unique backgrounds that lead to those functional issues?
Dr James Kinross: So, so I think what I what I've definitely begun to do, the word I would use, the kind of medical jargon word I would use is phenotype. So what I've begun to do is like I can now, if you like, put these patients into specific groups, right?
Dr Rupy: Do you want to explain what a phenotype is?
Dr James Kinross: Yeah, I will do. So, so a phenotype means like the physical manifestation of a of a of a of a gene, right? So I've got brown eyes because my genes program me to have brown eyes, right? So what I mean by that is that um, when someone comes into my room, usually I have to spend quite a lot of time listening. Like the first trick if any doctors listening to this is just really, really listen. And uh, you've really got to listen. You've got to give people enough time to really talk because a lot of the things that we've just described are actually really hard to talk about. And sometimes it takes more than one visit, it takes two or three visits. And I think a lot of the people that come to see me are really damaged. They're really mistrusting of medical professionals. They've been told a million different things and it's not worked and they're just in agony. And um, and so it takes time to build trust and the only way you can do that is through listening. Um, and you've got to give room people to talk freely. So that I think is a really key piece of advice. So, so when it comes to that and you've been through that listening process, I think you can really group them into gut brain people. So people who have had some problem in the way that the brain and the gut have developed and that might be because um, it was something in the gut that triggered the brain or it might be something in the brain that triggered the gut. It's a two-way thing, right? But there's definitely a gut brain people. There's definitely a post-infective people. So there's definitely people that went, I went on holiday to Thailand, I had a dodgy curry and now my world has fallen apart and I've been like this for, you know, a year and I don't know what to do. That's a post-infective kind of thing. And that's a wholly different thing. There's definitely, this is going to be even, this is going to be really controversial, right? But there's definitely a public school thing.
Dr Rupy: Oh, really?
Dr James Kinross: For sure. It's there's a boarding school thing.
Dr Rupy: Wow. Uh-huh.
Dr James Kinross: I honestly, like
Dr Rupy: Let's go into it.
Dr James Kinross: Yeah, like I just I really think it. Like and I'm a product of it, right? So, but like there's definitely something in kids that were in that were in boarding school which I is super, super interesting to me and and I think it's a combination of two things. I think it's partly psychology and and partly um, you know, uh biology. Uh-huh. Um, I think there's definitely a group of kids who um, sorry, a group of kids that kind of really struggle in that environment and um, they probably have a it's probably in the gut brain group really. But but I've really noticed that. Um, there's definitely a group of people that have genuine food intolerances and very, very rarely proper food allergies. And um, you know, I think lots of people are now very, very um, aware of food intolerances and they will sit down and they will say to me, I've got a food intolerance. And I'm like, do you really? And they're like, yes, I do. And and they will know what they've got. And sometimes it is and sometimes sometimes it isn't. So that's how I think about it. I think about gut brain, post-infective, nutrition and diet. And then I've also got like an other box. And the other box is like, what am I missing here? That's like my clinical light brain going, uh, am I missing like proper organic pathology, like what I would call like diseases, like diseases that I can diagnose and I need to know about and I need to treat with a medicine. So my process is to rule those out, make sure we're not missing anything, make sure everyone is comfortable and we're not we can have a conversation about function and then to break it down.
Dr Rupy: Sure. The public school thing, I think is very interesting. Do you think there's some trauma in that? You know, the obviously
Dr James Kinross: 100%. And I think if you, um, I think if you kind of, there's been lots of quite good books written about this recently and I think there's a whole branch of psychotherapy purely devoted to it. And I and I think it is trauma. I really do. And I think, um, but I think it's also learned behaviors. I think when you're in an institution and your gut and gut function becomes regulated by the institution and trying to unpick that is super, super challenging. I also think nutrition and diet plays a big role. Like, you know, you're you're the foods that you eat are kind of become very homogenized and very consistent. And then of course, I, you know, I listen, I'm a microbiome scientist. For me, all when you've got a hammer, everything's a nail, right? But, um, I I I think, well, we absolutely know when you go into institutions, particularly at um, in in in early life that those microbiomes homogenize. They they align. And that happens in care homes, it happens in prisons, it happens in offices, right? And I think in schools that's super important. I think one of the reasons it's really, really important is puberty. So, so, um, bugs in the gut have a very important role in defining how hormones work, particularly sex hormones, so testosterone, estrogen, progesterone, for example. Uh, and there seems to be quite an important interaction between bugs and these hormones and gut function, right? Which is part of the reason why we were talking earlier about like periods and stuff, why it's so important in in influencing bloating and these symptoms in women who have that um, that that particular set of symptoms around the time of their period. But it's also the same in boys. Testosterone is really, really important in in in regulating gut function and bugs sort of sit in between that. Now, what's interesting is that, well at least what's interesting to me is that um, that relationship seems to get locked in around puberty when you get these big hormone surges. And once that gut function is locked in at puberty, it's very difficult to unpick it. Um, and quite often patients will say, yeah, I was absolutely fine and then puberty kicked in or they will say, I was really suffering and then puberty happened and actually things got a bit better. Um, and it seems that that kind of time frame is very, very important. So I think if you're in if you're in a school environment where those biological pathways are getting locked in, uh, and they're not locked in correctly, that's problematic long term, I think.
Dr Rupy: Yeah. I want to talk about the estrobolome. We mentioned psychobiotics earlier and I think this this area of women's health and and the interaction between gut microbes and hormones more generally is fascinating. Perhaps we can talk about what the estrobolome is and and how that might change over time.
Dr James Kinross: Yeah, absolutely. But I I'll so I'll explain what it is before we do that, I'll I'm going to come back a little bit because we were talking about IBS. So, so what I think and I but I'll I'll explain why. So I what's interesting to me is that there are quite significant sex differences in what we call IBS between men and women. And women tend to be more constipated and they also tend to get more chronic pain. They tend to get more pain in the pelvis and they will have other kind of symptoms that that go with it. I'm not saying men don't get these things or men don't have chronic pain, but it's just more prevalent in women. And one of the hypothesis for this is that there is a bug androgen interaction, right? So these bugs and the hormones that that that we produce as as different genders or sexes seems to be quite important in determining that risk and those symptoms. And so, um, we are therefore interested in um, how microbes modify hormones and also how hormones modify microbes. And it turns out that's really, really important and it's really, really complicated. And the word that has been coined for that is the estrobolome, which is estrogen obviously. So what are the kind of broader system effects of of estrogen? Now, what's what's important to understand with that is that in keeping with our conversation, that that the estrobolome has an effect on gender-associated health or sex-associated health from, you know, conception all the way through to to death, right? And it might be that it's the setup that's really, really, really important. And if you perturb one or the other, because it's an access, an access, sorry, then um, the consequences might be quite long-lasting. And we're beginning to understand how that happens. So I'll I'll I'll talk a little bit of science, but I'll try and keep it, you know, simple. So the way the way that I think about it is that your nervous system has its own immune defense system. So all nerves have their own little cells, part of something called the innate immune system, whose job is just to defend the nervous system, but also to kind of prune it, make sure the nerves don't get out of hand, keep it all in check, right? Those cells are called they're called microglial cells. And you have them in the gut and you have them in the brain. You have macroglial cells, but we won't go into that. Anyway, turns out that the that how those microglial cells evolve and function is very, very dependent on um, they're they're sex dependent changes on how they on how they develop. And they develop very differently in men and women. And if you perturb them with antibiotics, the consequences are very, very long-standing. And it seems to be that you can influence a risk of chronic pain, certainly in animal models, and we seem to see similar data in human data. So you can influence chronic pain risk uh by uh giving antibiotics to these animals through the changes in those microglial cells because microbes sit between them. So there's like a there's a hormone, bacteria, microglial kind of access. And that seems to be a really important determinant in many of the symptoms that for example would explain why you have a sex difference in IBS between men and between men and women. Okay. And so you can use antibiotics to change the the the um the experience in those in those models. Yeah, so what we what I'm saying to you is that antibiotics changes how we experience pain in a sex dependent manner. And we think that, you know, hormones, bugs and immunology are kind of the key thing to understand if you want to explain that observation. So that's one example. But I think the estrobolome is really, really important. Well, we should talk about testosterone because that's equally important, right? But but um, estrogen and progesterone seem to be modified by microbes, or at least there is that interaction. And we think that that might be a missing piece in the puzzle of explaining why some why some women are more likely to get polycystic ovary syndrome, they're more likely to get endometriosis, these really terrible conditions that affect a lot of women and we just don't understand causation and our therapies are kind of really lacking in them. And so we're quite excited about studying the microbiome in in in that manner. Um, so there is clearly a, you know, the the, you know, the world that the kind of medical world is dimorphism. There's a there's a difference in the way that men and women experience lots of different diseases. It's not just, you know, sex specific diseases, it's cardiovascular disease, it might be dementia, it might be, you know, there's societal reasons for that, there's socioeconomic reasons for that, but there are also biological reasons for that. And it seems that bugs, hormones and immunology are a really important determinant of it.
Dr Rupy: So do you foresee, and and we're future casting here, so it's not something that you can just go out and start knocking up a probiotic concoction yourself right now, but uh a scenario where we will be using uh some sort of microbiota directed therapy to treat some of these issues like PCOS and um uh and and another hormone.
Dr James Kinross: Yeah, I absolutely do. And and there is work going on around the world at the moment to do that. And because if you understand the detail of that relationship, you can either knock down particular bacteria that might be driving, you know, causation or you can promote beneficial microbes that might prevent it. You may not even need the microbes. You might be able to replicate their functions or to give individual molecules that kind of bypass that whole interaction. But but you've got to understand, you've got to understand the mechanism. And I and I definitely think that is going to come. I also think that actually the key here, and in fact, this is a bigger point, I think the gift of the microbiome is not in treating diseases, it's in preventing diseases. So I want to know like, can we just stop someone getting polycystic ovary syndrome in the first place because it's a pretty rubbish thing to have. And I would argue that an important way of doing that is by really looking after human ecology in very early life and probably from conception. Okay. And and we have a big problem with many of microbiome studies that look at these sorts of conditions because they look at the condition well after the horse has bolted. Like if you're studying the microbiome when someone's got endometriosis, well, it's you can derive some useful information. I'm not saying it's a bad thing to do, but if you really want to understand causation because of the evolutionary importance of the microbiome, because of the changes in the microbiome over a life course, I argue you've got to go, you've got to go back early in life, otherwise you're going to miss it.
Dr Rupy: Yeah.
Dr James Kinross: Which is why in my group, we are increasingly studying infants. Like I'm a, I mean, I I treat grown-ups sometimes. Um, and um, but increasingly I'm I'm I'm of the belief if you want to understand a condition like, you know, cancer or inflammatory bowel disease and other conditions that I study, you've got to go back, you've got to go back early, otherwise you're going to miss it.
Dr Rupy: Yeah. And with regards to the estrobolome, are there things that people can do now to sort of uh create a more flourishing uh microbiota that can perhaps not completely get rid of PCOS and endometriosis symptoms, but at least improve the ecology that could mitigate some of those issues?
Dr James Kinross: So I think there are, um, but but I think it's tricky to do that in a really direct way. But there are some common sense things to do, right? And um, common sense things would be to um, assuming that you've already worked with a gynecologist and you're getting all the kind of established medical therapy that you need, would be to really think with about your diet and to work with a dietitian because many foods that you will have will have high levels of phytoestrogens or food-based estrogens that will influence your symptoms and you can target those in a really specific way. It might be that you need more, it might be that you need less. Um, and I think you can look after the ecology of your gut, right? So that means doing many of the things that we've been talking about, but also it means um, you know, trying to avoid things that damage it. So the problem that many patients like this have is that they will go to their doctor with pain or with other symptoms and quite often the output of that is an antibiotic. Yeah. Right? And quite often, or for example, they get recurrent urinary tract infections and the treatment is antibiotics, more antibiotics, more antibiotics. And that just takes you further and further and further away. So, you know, my strategy in this is to try and measure what's going on. That's why I measure it because at least you've got an objective, you know, some objective measure. And then to try and slowly um, wean um, off those antibiotics through nutrition, balance, diverse diet, uh, thinking about all of those other kind of levers that we're talking about before, gut brain levers, hormone levers, these sorts of things to try and make that change.
Dr Rupy: Yeah. Gosh, I I can see that we're running out of time, so I want to try and make these quick fire, but these aren't quick fire questions. I've got a few here. So, um, does the microbiota affect how we uh taste foods and our food preferences?
Dr James Kinross: Oh, I love that. So, yeah, it really does. Uh, yeah, it really does. And it it does it in the most interesting ways. So, your the oral microbiome is having a bit of a renaissance. We're there's a lot of work on it at the moment because we find bugs that come from the mouth in lots of different diseases. So we find them inside bowel cancers, we find them in dementia, we find them in lots of gut brain issues. Um, but they they definitely influence taste because for kind of for some obvious ways. So bacteria in your mouth will metabolize and break down the foods that you eat and they will release taste molecules onto the onto the taste buds. But they will also compete with other bacteria and viruses in the mouth that um, that might have a direct impact on your on your taste as well. Um, they change the immunology of the mouth and they will also influence, you know, different types of taste in in particular ways. Interestingly, I find it interesting again, I said that a lot in this interview, uh, is that um, taste really has an evolutionary basis, of course, right? So taste is a defense mechanism. If you've got something that's bitter or awful, you know, it could be poisonous, it could be toxic. And microbes have likely informed that relationship. And actually a lot of the actual receptors that live on the cell that determine taste, actually live on your macrophages and your immune cells all throughout your body, right? And so I really think about the gut as a sensing organ. It's really just a giant sensing organ and it's tasting food, you know, uh, literally as a sort of in an immunological way. Uh-huh. And it's sending hormones all of the time, like, you know, microbes are going to influence your appetite, you know, how you think about food in terms of maybe whether or not foods have certain addictive qualities, they might have an important role. And I I don't have any evidence to support this, but I think that also they're playing quite a big role in pregnant women who suddenly get weird food. Really? Like you you know, you suddenly get that I need gherkins and ice cream thing at two in the morning like my wife did. Like you I just think I think microbes are playing quite a big role in that. I think they're signaling saying, hey guys, we need gherkins. That's what I think. Yeah, yeah. But I I we'll see if we'll see if the truth the truth comes to that. But yes, very, very important relationship between your microbiome, taste and how you experience and think about food. It's influencing how you think about food before you're eating it.
Dr Rupy: Do you think it's possible, and if they if it is possible, what what do you think is the time period for someone to retrain their taste buds to appreciate the quote unquote healthier foods. So the pulses, the uh the the bitter leaves, the dark green leafy vegetables, that kind of stuff. Do you think like because the the the issue that we have with the Doctor's Kitchen recipes is that we introduce a lot of that food, but some people just don't like, you know, dark chocolate and they don't like spinach, for example. Is there is there sort of a way in which any evidence that that says that, you know, if you stick to this for two weeks, let's say, your taste buds actually change and your microbiota actually forms a relationship with it?
Dr James Kinross: I I so I have to be honest and I don't know of any evidence around that. But what I do know is that within, because we've done these studies, within within two weeks of making sustained dietary changes, your microbes will will change and their functions will change. So it's plausible to me. Of course, there might be agents in that food which have really got nothing to do with bacteria, which are, you know, having a direct impact on your taste buds and that actually you're just never really going to get round to it. But it's intuitive to me that if you make, it's a bit like, it's a bit like treating an allergy. Like you don't just, you know, if you've got a peanut allergy and you want to get over it, you don't just eat a big bowl of peanuts. That would be really silly and you would die, right? It's the same with taste. Like you need to just slowly and incrementally make those changes and give your your ecology time to catch up. It's the same in IBS and like treating functional gut problems. Like the changes that you have to make to get back to a diverse diet, you've really got to do slowly because those microbes have got to evolve, they've got to they've got to grow back and then they've got to start switching on those metabolic functions to break down the foods that you're going to eat. And it just takes a lot of time. So I think, you know, it's intuitive to me in that instance that you would just make very subtle and nuanced changes to the sorts of flavors that you're consuming and then build them up over time. And who knows, one day you might really enjoy it.
Dr Rupy: Yeah, yeah. I mean, I certainly had to retrain my taste buds when I started transitioning to like a healthier palate. And now I can't like think of a day where I don't crave greens. And I I know I sound really weird by saying that, but that's genuinely like how I feel and it didn't take that long for me. Um, okay, vegetables. Uh, do they create uh the the same molecules that we find in anti-obesity drugs? So uh the GLP-1.
Dr James Kinross: No, not at all. So vegetables are much, much better for you than anti-obesity drugs. And I really recommend vegetables. Like, do take have vegetables. I mean, what's interesting, so you're you're referring to, you know, a class of medicines like Ozempic, I presume, right? So which the way that they work is they block a lot of the hormones in the gut that signal appetite. So they suppress appetite. What they also do is dramatically change your gut function. So we've had lots of instances of patients being admitted with abdominal pain, diarrhea and really quite significant changes in your gut function. They very obviously change the microbiome, not in a good way. And um, you know, it's much better not to be on these medicines if you possibly can. What vegetable vegetables, what fiber does, fiber works in a number of different ways. So first of all, it creates like a gel. It creates like a sort of soft scaffold, if you like, which sits in the gut and that has some of its own physical and chemical properties. So it absorbs toxins, it takes toxins out of the gut. It might take a bunch of horrible bile acids that you don't want or, you know, secondary metabolites that aren't very nice produced by, you know, animal protein fermentation, for example. Um, but it also might have a um, you know, a biomechanical effect on the gut that's quite happy. The gut doesn't like working too hard. And it has an immunological effect on the gut. And that is often mediated through microbes because fibers have um, a prebiotic function. So a prebiotic is a fiber that you can't digest but that microbes can that has a health benefit. So examples of that might be inulin or galactooligosaccharides and many of these fibers are found in plant-based foods, right? And and they're just naturally they're natural in plants. And so what happens is that microbes will break those down and the secondary benefit of that comes from the small molecules that they produce. So we've mentioned in this chat like short chain fatty acids, a really good example, butyrate would be a really good example of that. Um, and of course, it also has lots of other goodies like polyphenols and these kind of plant-based molecules which microbes quite like and and have direct benefits, you know, in and of themselves. So we really like fiber. If you just have, I think my favorite fact is that if you just have seven grams of fiber per day, I think it's about two grams in an apple, something like that. Two and a half apples a day, your risk of diabetes will go down, your risk of obesity will go down, your risk of cardiovascular disease will go down, your risk of cancer will go down, your risk of, you know, um, dementia will go down, everything will go down. And we've known, we've known about this, you know, since Burkitt did his like really famous work in the 1970s. Yeah, it's so hard to do because it requires sustained behavior change.
Dr Rupy: Yeah. And that's why your work is so important because it changes people's behavior and it makes eating vegetables sexy, which I think is, which I which I think it is, Rupy. I think they are sexy. I think vegetables are sexy. Yeah.
Dr James Kinross: Yeah.
Dr Rupy: Uh, did did Romeo and Juliet get together because of their microbiome?
Dr James Kinross: Oh, yeah. Like it had nothing to do with with with Shakespeare. So, so I think you've asked me that question because I think hormones, we've talked about hormones and because microbes influence how hormones work and because microbes influence how we look and how we smell, they produce pheromones and they modify our behavior. I think they have a role in mate selection. Like we know this from lots of other species and lots of other animals, which is the point that I was making. So I think I explained the the study of the fruit fly where a fruit fly will mate based purely on pheromones. And if you give it an antibiotic, it can't get a girlfriend. It just cannot mate. But then if you reintroduce just a single strain probiotic, suddenly it's sexy again and it can it can procreate. And we've got lots of other examples of this throughout the animal kingdom. And I just think we're probably not quite as different in that regard as we like to believe that we are. And and the other point that I was making is that we we often think about sex and sexual health in terms of pathogens. Like there are 80 million sexually transmitted infections in the US each year. They cause a lot of harm. Like if you're having a baby, we screen mothers for pathogens because we know that those sexually transmitted pathogens will cause harm, right? But we don't think about the role that mutualists and commensals have in protecting us and and keeping us um, healthy in terms of our sexual health. And we also don't think about the benefit that sex has in maintaining our our microbes. Yeah. So when you kiss someone, for example, like you, you know, you're a good snog will transfer about 80 million bacteria. And there's an evolutionary benefit to it, right? So you like you can go back and study like the transmission of microbes from Neanderthals, you know, into Homo sapiens. And we can track microbes evolving between the two, right? And and sometimes they transmit functions that you might need. So for example, you know, metabolizing amylase in in your mouth. So, so we just we don't think about bacteria in in in in that sense. It comes back down to what I was saying about like a 19th century way about thinking about bugs, right? What I'm really arguing for in this book is like we evolve from germ theory into microbiome theory. And what microbiome theory says is, yeah, pathogens are bad. You've got to kill pathogens. They kill people and we don't want them, right? Like we're seeing an outbreak of monkeypox at the moment, right, globally. It's a disaster. It's really bad. We need to stop that. But at the same time, microbial conservationism is a valid and really important way for promoting health and keeping us healthy. And that's the same in your sex life as it is in your aging strategy or, you know, your kind of day-to-day life.
Dr Rupy: Yeah. Um, we're going to bring this to a close, but I I I wonder if we could, and there's so many things that you could talk about, but if there were three things, three takeaways that you could leave our audience with that they could start doing today with microbial conservation in mind, what what would those what would those be? What what are the top of mind things?
Dr James Kinross: So my number one is is think very carefully about antibiotics. Okay. Antibiotics are an incredibly precious medicine. I'm not anti antibiotics. I need them. I can't do my job without them, right? And and and they save lives. But we equally misuse them. And so I would like you to think carefully about them, which means that if you're seeing your doctor because you've got a cold, make sure that you really need it before you take it because it might be viral and you might not need it. And the consequences of taking it are really, really important, particularly if you've got kids and your kids are needing antibiotics. If your doctor says you really need it, you really need to take it, right? I don't want to be that, you know, extreme about it, but we just need to be quite careful about it. And I also want you to think about antibiotics in the foods that you eat. So when you're at the supermarket and you're about to buy that chicken, you're about to buy that steak, think about whether or not you can honestly say whether or not antibiotics have been used unnecessarily in its in its production. And in the United Kingdom, post-Brexit, we were supposed to have a bunch of, you know, legislation come in to protect to protect us from this and animal husbandry, and it hasn't happened. So ask your butcher, ask your whoever you get your food from, have antibiotics been used in this and what is the strategy for it? And I I would really, you know, I think that's an actionable thing you can do. And I think in the United Kingdom, we're behind the US on that. I think if you go to a US supermarket, you will see that they actually have quite commonly antibiotic information. And we just don't do that enough in the UK at the moment. The second thing is fiber, fiber, fiber. Okay? Vegetables are sexy, eat more of it. Like you there's a lot of this in the kind of zeitgeist at the moment about plant-based foods. It's not made up, it's really true and you don't need a fancy app and you don't need to spend a bunch of money on it. You just need to, you know, have the cooking repertoire and the time to really, you know, um, focus on it and it will really, really help. Like it's just it's going to help and you're going to feel, you're going to feel much, much, much better about it. And the third thing that I would really like to say is see your friends more. Okay? So socialize, spend time with your spend time with your family. I know family is not always the easiest, but like actually, like, you know, I think it's important. Like I think that um, we know that big family groups, big social networks, it's good for almost every aspect of your health, right? It's good for your mental health, it's good for your physical health, you're going to live longer. And uh, and part of the reason for that, I believe, is that because you're going to have a more diverse microbiome. But I think there's lots of other kind of health benefits to it. So I think that would be my top three.
Dr Rupy: Yeah. Gosh, this has been such an awesome conversation. I haven't gone through even half of the things that I wanted to talk to you about because there's just so much in the book, but I I I highly recommend everyone pick up the book. Medics uh especially actually because I think there's just a lot of groundwork knowledge that a lot of us would would benefit from uh from knowing about and also like that's sort of being a platform to dive into it a little bit more. Um, so it's brilliant. We're going to have to have you to come back on.
Dr James Kinross: I need no encouragement. I'll be back in a heartbeat. You're going to have to cook for me though next time.
Dr Rupy: Yeah, no, we'll definitely we'll do something in the kitchen for sure.
Dr James Kinross: Oh, I love that. I'll be so fun.
Dr Rupy: Yeah, yeah. We'll definitely put point number two in uh in that.
Dr James Kinross: Or what we can do is we could come and sequence out your microbiome, Rupy. We could do a meal and we can do that.
Dr Rupy: Yeah, yeah.
