A Healthier You: Your gut’s guide to a happier microbiome

0:05Hey, TED Health listeners, it's Dr. Shoshana Ungerleider. As part of our series, A Healthier You, we're diving into a topic that affects every single one of us, our gut health. And I'm really excited about today's guest because she's one of the leading voices in this space. Joining us is Megan Rossi, an internationally recognized registered dietitian and nutritionist with a PhD in gut health. She's made it her mission to empower people with practical, evidence-based advice on our gut. Megan, also known as the Gut Health Doctor, founded her platform in 2017 to combat the overwhelming misinformation out there about this topic.

0:46She's dedicated to making science-backed nutrition advice more accessible to everyone. Megan is also the founder of the Gut Health Clinic in London and has published over 50 scientific papers on topics like prebiotics, probiotics, and nutrition-based therapies for the gut. She's also the co-founder of Bio and Me, a functional food brand, and the author of the best-selling book, Eat Yourself Healthy. Today, we're going to be myth-busting some common misconceptions about gut health, exploring the connection between digestion and overall well-being, and laying out how simple changes to your diet can transform your health from the inside out.

1:25But first, a quick break to hear from our sponsors.

1:37Dr. Megan Rossi, thank you so much for joining me. It's an absolute pleasure to be here. You've said that gut health is the cornerstone of overall health. Can you talk more about that idea and maybe how does the gut influence areas of our body that people might not expect, like our mental health or our skin health? Yeah, really good question. So when we talk about gut health, I like to start by explaining what actually it is, because I know everyone's starting to hear that because it's like a hot topic at the moment, right? But when we think of gut health, it actually relates to this nine meter long digestive tube that delivers food from entry all the way to exit.

2:10And that whole nine meters is what we talk about with gut health. Now, that's important for immune system, for digestion. But the thing I think that's brought the fame and the excitement and what I did my PhD in is the fact that it contains trillions of these microorganisms. And it's these microorganisms like the bacteria that we're actually seeing can do so much for the human body. In fact, humans probably couldn't survive without them. The new research coming out highlights that, oh, God, if we don't look after it, other organs are not going to thrive like they potentially could. So it's a really exciting area of research at the moment.

2:45Your clinic addresses mental health through gut health interventions in addition to other things. Can you explain a little bit more about the gut-brain connection and how targeting the gut can influence our mental health? Yeah, absolutely. So at the gut health clinic, we look at all different areas, right? So we'd look at how we can target the gut through the right nutrition. And what we've seen through the scientific research studies is that influences systemically all our other organs in the body. And there's an amazing kind of landmark study which first showed this. And there's been repeated studies to kind of validate what they found.

3:16But it was a SMILES trial and it was undertaken by some researchers back in Australia. And what they did is they took people who had moderate severe depression and they randomized half of them to this gut boosting diet. So really nourishing those trillions of bacteria through the food that people were consuming. And the other half had this befriending type of counselling. And they followed either of the interventions for 12 weeks, seeing the researchers the same number of contact times. And then they reassessed their mental health using these questionnaires we often use in clinical practice. And what they found in the diet group, 32 % of them had a significant improvement in their depression scores, which would have classified them as no longer clinically depressed.

3:55in the control group that was only eight percent these people had moderate severe depression but i hope that it gives people kind of the encouragement and empower them to see that as an adjunct therapy as an additional therapy a lot of their mental health they can help control and certainly what i've seen in my own clinic is that you know with the support of the prescribing medic for patients who wanted to come off of them a lot of patients have not all of them depression is very heterogeneous, but quite a lot of them have been able to come off by targeting the microbiome through gut nourishing foods.

4:30So you started the Gut Health Doctor to combat dangerous fads and myths. What's the most damaging myth about gut health that you've come across? Probably one of the main ones is around restrictive diets, which sounds a bit benign. People think, look, I can cut things out of my diet and I'll just reintroduce and it's all fine. but actually what I see in clinic is that when people cut foods out they find it really difficult to reintroduce because their microbiome kind of particularly high fiber foods like legumes and grains actually lose some of the ability to digest some of those fibers so they might cut them out thinking look I've heard gluten's bad so I'm just going to cut it all out and I've heard legumes are bad because the lectins so I'm going to cut them all out and they cut them out for a couple of months and go, oh, actually nothing's improved.

5:16I want to reintroduce. They then try to reintroduce and their microbiome doesn't have those enzymes anymore. They're not very efficient at digesting it. So people then start to get digestive issues when they reintroduce. And then as a result, they're like, oh, my body doesn't like these. These are really bad for me. And then they cut them out. Right. And again, it sounds like, oh, you can live without legumes and whole grains and things like that. But what we see in the scientific literature is that cutting out these groups in the long term actually can do a lot of negative things to microbiome.

5:48It can reduce down the diversity of those different bacteria that live in you that can have anti-inflammatory effects and produce antioxidant chemicals and all that sort of stuff. And that's not to say that folks with celiac or other, you know, diagnosed illnesses or around gluten or shouldn't, you know, refrain from eating it. You're talking about just in general when people who are, you know, have not received a diagnosis, cut back on something just to see what happens. And then this can happen. Yeah, absolutely. That's a really good point. What frustrates you the most about the way gut health is discussed in mainstream media or in the wellness circles these days?

6:26Probably one at the moment is all of these natural supplements. They just whack gut health on the front of it. And people are like, oh, it's going to cure all my gut issues. And people don't necessarily realize that just because it's natural doesn't mean that it's not harmful because we know a lot of herbs, you know, really high doses actually can have antimicrobial effects and not just kill the bad guys, but actually kill the good guys as well. So I think people need to be really careful of these quick fixes that are advertised for gut health because in all honesty, there is no secret pill that's going to give you ultimate gut health.

7:03You do need to put in those hard yards and fertilize the microbiome on a daily basis with whole foods. That's boring, but honestly, that's just what the science is saying. I want to come back to something that you touched on before, because I think this comes up for me in my clinical practice and among my friends all the time. Many people are turning to restrictive diets like gluten-free, as we discussed, or low FODMAP without professional guidance. Can you tell us a little bit more about how these diets can harm us if they aren't used properly or under supervision from somebody who really understands it?

7:43Yeah, absolutely. So I think most people know about gluten-free diets, but maybe low-fodmaps diets is something that they haven't come across. So this is a medical diet, right? It is incredibly effective in the short term for helping with kind of severe irritable bowel syndrome, which affects around one in 10 people. What we do in clinical practice with a low FODMAP diet is reduce down these certain types of plant foods. These foods that we reduce down are actually prebiotic. So these are fertilizers for the microbiome. So essentially a low FODMAP diet, which is this medical diet, actually starves the microbiome just to give that gut some rest as it kind of rebalances itself where we know that irritable bowel syndrome is this disconnect between the gut and the brain.

8:27There's too many nerves innervating the gut and making it really sensitive. So when people have these prebiotic foods, which are really healthy for most people, it can create a lot of pain and distension. Then we need to just reduce them down while your gut gets some calming. And we do other therapies during that, like gut brain access work and different supplements can also help in that scenario. That restrictive stage of the diet should only ever be followed between four to six weeks. Our team at King's and many other research groups have shown that staying on this diet for too long actually not only reduces down really important nutrients like dietary fiber and calcium, but actually has a negative impact on some anti-inflammatory bacteria like bifidobacteria.

9:12And that bifidobacteria has actually been associated with reducing stomach pain as well. So it's this vicious cycle people kind of get stuck in with this over restriction. So absolutely, you know, these diets which people might feel like, oh, actually, I'm not getting bloated in the short term and my eyebrows feels like it's under control, should never be followed long term. It's about after that restrictive stage, you go through this reintroduction stage. And that's all about training your gut and your microbiome to tolerate and enjoy it. I want to jump into the immune system. So how does our gut microbiome affect our immune system?

9:50And what can we do to best support it? Yeah. So we know 70 % of the immune system lives in the gut, right? So we've got the immune system, we've got the gut living side by side. And what we see, particularly, you know, the first thousand days of life in babies is a microbiome is really important for teaching the immune system what it should react to and what it's safe to just leave. So for example, then teach the microbiome that a virus, you know, cold and flu virus is bad. So you should mount that reaction and therefore, Or, you know, try to fight it off and don't let it get into all the cells and things like that.

10:24So a microbiome is so, so important, particularly that first thousand days of life for teaching our immune system what to react to and what not to react to. So we know very early on that that's an important one. And then we see through the aging process is that people who have a more diverse microbiome seem to be less likely to get the cold and flu. Or if they get cold and flu, they're less likely to have to take days off work because the symptoms aren't as bad. And even we saw that with COVID-19, where people with more resilient microbiomes, better gut health, were at lower risk of becoming unwell with COVID.

11:00And actually, this is an area where there is some good scientific evidence for a probiotic. So Cochrane reviews have suggested that specific combinations of these strains of bacteria can help reduce our risk of the cold and flu. And the bacteria for that one is Lactobacillus rhaminus GG and BB12. So you've done extensive research on probiotics and prebiotics. In your opinion, are we over-relying on things like supplements, like probiotics and others to fix gut issues instead of focusing on diet? Yeah, a very good question. So I actually did my PhD in pre and probiotics. So I feel quite passionate about the probiotic concept.

11:42And essentially, the truth of the matter is we've kind of gotten probiotic use wrong. There's actually no scientific evidence out there that suggests we should take a daily probiotic for good gut health. It just doesn't exist. For good gut health, we need to eat that plant diversity, the whole foods, fertilize our microbiome that way to nourish them and they all grow and thrive. But that's not to say that probiotics are useless and have no benefit. Then we talk about probiotics, they're all different bacteria, which are called strains. So we need to take the right strain at the right time in the right way.

12:12And an example of that, where there's international guidelines, if you have to go on antibiotics for whatever reason, then the guidelines say that you should take a specific strain called Lactobacillus raminis GG, so LGG. You would take it throughout your antibiotic period and for a week after at a dose of 10 billion units twice a day. Now, a lot of people probably listening to this will be like, oh my God, do I need to write down that? So it's very therapeutic. And it is therapeutic, guys, but that's the way we have to treat probiotics to have the benefit. You know, like you would never go and take an iron supplement if you've got a vitamin D deficiency and expect your vitamin D deficiency to improve because you took iron, you took the wrong one.

12:52The same goes with probiotics. We need to be very therapeutic and specific about them if we want a therapeutic outcome. Yeah, yeah, absolutely. That makes perfect sense and something to be thinking about in the context of antibiotic use. And a lot of doctors like me don't know a lot about this stuff. So I think that's really helpful. Megan, how does our gut microbiome change as we age? And what can older adults do to maintain a healthy gut? Yeah, really good question. And there's kind of different schools of thoughts around what happens to our microbiome as we age, right? So there's no real consensus as to is there a certain age where our microbiome starts to reduce down the diversity.

13:33So remember I mentioned before that diversity is kind of associated with a healthy microbiome. When we look at the research studies, some studies suggested age of 60, that diversity starts to decline. And other studies have suggested actually, if we maintain a really healthy diet and keep the practices of, you know, exercising and good sleep and low stress, probably a microbiome diversity doesn't alter too much until the age of 80. So it's a bit of a chicken and the egg. It's a thought of, well, actually, are we seeing these earlier stages changes when we age due to the fact that we start to, you know, be less active?

14:10We kind of just go to our habit foods. Maybe, you know, our teeth aren't as strong, so we avoid the fiber or we kind of get fuller quicker. So we're not having these high fiber foods and therefore our microbiome changes. And that might create a little bit more inflammation in a negative way and that might prematurely age us. you have talked about the importance of plant-based diversity for gut health what does a gut-friendly diverse diet actually look like on a day-to-day basis when we say plant diversity a lot of people think oh gosh that means plants only but that's not the case at all right so we know things like fermented dairy like kefir and quality cheeses and wheely fish and things like that have all been associated with a healthy microbiome However, we do know the foundation of a healthy gut loving diet is very much around these whole plants.

14:59And that's because fiber, which we've all heard before, everyone's kind of like, nah, it's so boring. I don't want to talk about fiber. Fiber is incredibly important. And it is something, like I said, most people aren't getting enough of. We need at least 30 grams according to most guidelines. It actually is quite achievable. It's just thinking about ways you can add more plants to every meal. And for those people who are like, cool, get fiber, they want that next level up. That's when I talk about the super six plant-based food groups. So essentially there are six food groups. We should typically be trying to get something from each of the six groups every day to really feed those microbiomes.

15:39So it's your legumes, the things being like your chickpeas and butter beans, your whole grains, things like your quinoa and your barley and your oats. you've got your fruit you've got your veggies um you've got your herbs and spices and your nuts and your seeds they all provide your microbiome with different types of fertilizers so they nourish different communities of microbes which all have different skills so thinking about your own diet have i had something from the super six today if not you might want to think okay how can i add some legumes to my diet whatever you're having for dinner literally add a can it could be takeaway You know, you can have a curry takeaway for dinner, literally add a can of mixed beans in, just get the ones in the water.

16:19It could be pizza. It could be bolognese. Cut out half the mince, add a can of mixed beans or lentils. So you still treat your taste buds, which means that it's a diet that has more longevity because if we don't like the taste, we're never going to convert, but also nourishes this community of microbes that has so much power and potential. I've seen it, you know, transform people's lives in very real but often surprising ways. Such great tips. Thank you for that. So Megan, in your research and from your perspective, what have you found to be the biggest factor contributing to what seems to be a rise of gut health issues in modern day?

16:58There's a lot of things at play, but I would say probably one of the biggest ones is around the fact we live very busy lives. Eating on the go, we're checking stressful emails, we're replying to friends and all of that sort of stuff. We've got the stress hormone cortisol pumping throughout our body. And that means our digestive system is not really prepared for proper digestion and therefore malabsorbing certain foods and that's leading things like bloating and altered poops and all those sorts of things. So from a functional perspective, I would say that taking some time out to eat your food mindfully, doing some diaphragmatic breathing to breathe in through your tummy instead of your chest five minutes before a meal can really help if you are suffering with those kind of pesky gut symptoms, right?

17:39And then if I think more deep-seated issues with the gut microbiome in terms of lower diversity, more inflammation and things like that. I would probably say our reliance on these ultra processed foods, keep in mind how we can start to revert back to these whole foods and, you know, reduce down on the processed foods, which aren't going to be toxic to you, like maybe some reports are saying, but the fact is that they starve the microbiome and a starved microbiome, they get hangry and they start to do bad things to your body.

18:18So how does gut health differ between men and women, if at all? And are there specific things that women should focus on to optimize their gut health? Yeah. So in terms of differences, we know sex hormones, like testosterone, estrogen, do change our microbiome, but equally our microbiome has a role in regulating them. We know that yes, sex hormones are changing our microbiome, but what I would say is it's not strong enough to overpower diet. So I couldn't look at someone's microbiome results and say, oh, that's definitely a male or that's definitely a female because things like, are they moving their body?

18:52Are they sleeping? What sort of diet are they having would outweigh those sort of factors. But we do know, you know, the sex hormones are changing the microbiome to some extent. You know, it depends, I guess, what the life course, you know, where you are because hormones in our female bodies changes so much. So there's interesting research that suggests that women who are still having their periods, if they're having, you know, painful periods, they're more likely to have painful periods if they're not having two pieces of fruit a day. And then, you know, people are going through the menopause.

19:24Again, these are association studies. So we need more research in females, which is sadly an under-researched area. But for now, let's look at the research that we've got. And it suggests that women who are on the upper end of having regular intakes of oily fish and legumes actually seem to be able to delay the natural menopause. So there's a whole lot of, yeah, really fascinating stuff coming out around looking at how we can more specifically tap into that based on the research we've currently got, which is sadly not that much. So you've received significant research funding and published over 50 scientific papers.

20:01What's the most surprising discovery that you've made in your research so far? Oh, that is a good one. Something that really, maybe it didn't surprise me, but I think it is really fundamental to people being aware of, of where we are with microbiome research. So what we were looking at is whether we could use the microbiome. So finding out what microbes are living there to predict response to different dietary interventions, whether that was probiotics or even a low FODMAP diet. And what we found is the microbiome actually didn't really help predict. But what did help predict is the metabolites, the chemicals that the bacteria were producing.

20:39So it kind of opens up this new way of thinking where we don't need to necessarily fixate on what microbes we have living in our gut. We need to fixate on what they're actually doing. And a good example of that is that you can have identical bacteria living in two different people's guts. And in one person's gut where it's treated really well, it can do really beneficial anti-inflammatory, antioxidant types of things. In the other person's gut where that bacteria is treated really poorly and starved, it can do really negative things and promote inflammation and things like that. So just because you've got specific bacteria, if you don't nourish the environment, they can act very, very different, right?

21:20And the same is that you can get two very different bacteria and actually they can do a lot of the same functionality. So there's a lot of these commercial tests out there for microbiome testing. And what I would say is that they are very early stage. I think what will really open doors is the metabolites. So what the bacteria are doing more so than who's living within us. Because people often think that if you have a specific gut bacteria, oh, that's a good thing. But what you're saying is the environment and how they're behaving and interacting maybe with each other is really, really important.

21:52So in closing here, you know, gut health is at the intersection of multiple disciplines. How do you think the future of healthcare will evolve with this growing understanding of our gut microbiome? It is a really, really exciting time. But also, like you mentioned, it's not something currently in the curriculum for medicine, you know, for psychology, for nutrition and dietetics, because it is such a new science. So I think it's going to be really interesting how we start to teach at university degrees this new area of research, and whether actually it's going to require a new specialty, because it is, you know, quite involved.

22:35And therefore, you know, we can't just tack it on like a week extra in a degree to kind of learn about this new area. But absolutely, I think we do need to look at the system as a whole, where we've got, you know, the cardiologists and gynecologists and all of that, you know, very separate sticking to their organs, what's going to unite everyone is the microbiome. So I think there will need to be this kind of cross disciplinary approach to the human body to really elevate this area. Megan Rossi, you're amazing. Thank you so much for this conversation. I, today, I'm going to be writing down those super six, and then I'm going to sit down to have my lunch.

23:13So I promise you, I'm going to do it. I'm going to check in in a week's time and see how compliant you've been. Okay, good. Let's do it. Thank you so much. Thanks for having me. It's been fun.

23:31And that's it for today. TED Health is part of the TED Audio Collective. This episode was produced by me, Shoshana Ungerleiter, and Costanza Gallardo, edited by Alejandra Salazar and fact-checked by Vanessa Garcia-Woodworth. Special thanks to Maria Lagis, Farah Degrunge, Tali Emlin, Daniela Balarezo, and Roxanne High Lash. If you enjoyed today's episode, rate and review the show on your favorite platform. It helps other people find us. And I'd really love to hear your feedback. Send me a DM at ShoshanaMD on Instagram. I'm Dr. Shoshana Ungerleiter, and thanks for listening. you