gut health podcast

E01: The Holy Gut Podcast – Understanding Gut Health


Nick: Welcome to episode one of The Holy Gut podcast, the podcast that answers your questions about gut health.

Hello, it’s Nick Kemp, here, co-host of the Holy Gut podcast, with my co-hosts, Dr. Nathan Connelly and Nicole Starbuck-Connelly. Nathan is a gastroenterologist and Nicole is a registered nurse and practice manager of the Moonee Valley Specialist Centre here in Melbourne, Australia. Moonee Valley Specialist Centre provides a number of services related to gut health, including FMT and bowel cancer screening. Welcome to the first episode, Nathan and Nicole. You guys own the center, manage it, work together, and are married.

Let’s begin with the name of the podcast, The Holy Gut, Nicole and Nathan. You converted a church into your practice center. Do you want to talk about that for a minute and give us some background?

Nicole: Sure. Thanks, Nick. Nathan and I have run this practice since 2011 together. About a year and a half ago, we decided to buy a church. We converted it into our practice, where we spend most of our time. We have a gastroenterology practice, and Nathan’s also a medical physician. We have lots of different ways that we can look after patients. Nathan does things like gastroscopy, colonoscopy, fecal microbiota transplant, as well as lots of breath testing, and he also looks after the liver. So it’s an all around gut center, I guess.

In terms of Nathan’s career, he’s been a medical physician for over 25 years. He’s done a lot of training in that time, and he’s a specialist in gastroenterology and general medical. I’m a registered nurse and have been for over 18 years. I’ve worked in lots of different places and now, not only do I run this place but I’m also the main nurse here. I spend a lot of my time doing iron infusions, liver scans, and making sure that all of our patients are looked after properly and individually.

Nick: Fantastic. Okay, so the name really is about where you’ve located your business, which is a converted church. And as you just mentioned, you provide all those services and you’d be very qualified to talk about the topic of this podcast, which is gut health. So let’s begin with that, Nathan. What is gut health?

Nathan: Nick, I think the best way to answer that is in two parts, really. The first is what, as a gastroenterology trainee, I was taught, which basically is if you have normal gut function, no, you don’t have any nausea or vomiting or tummy pain or alteration in bowel habit like constipation or diarrhea, and if you do a colonoscopy and a gastroscopy, and they’re all normal, that’s a healthy gut. So it was all really about the absence of symptoms and the absence of any disease associated with the gut.

I think if you fast forward 20 years from that, I think the definition is much broader these days. There’s a recognition that gut health is more than just about the lining of the gut and all about you, if you like, but also about the bowel flora, or the inhabitants of your gut, which are actually being recognized or essential for good health. Not just good health for the gut itself, i.e. preventing people getting diseases in the gut, but also, possibly, preventing diseases elsewhere in the body. There’s been a lot of work done on whether gut health issues can impact on other organs, especially the brain and psychological well-being. So gut health really is about all those layers all working together to make a person healthy.

Nick: I see. I recently went to a book shop and I was astounded that the number of books on display on gut health, there would have been about six I actually saw on display, and then I’m sure there were quite a few hidden in the bookshelves. Obviously it’s becoming a bit of a buzzword, gut health. I’ve heard it described as almost that the gut can be almost treated like a second brain. So when we’re talking about gut health and more and more people are becoming interested or concerned about it, what things do we need to look out for to know that we’ve got a healthy gut?

Nathan: Well, that’s the interesting thing. It’s difficult to measure. I guess if you have no symptoms of gut dysfunction, i.e. leaky gut itself, and generally, you’re a healthy person, there will be no reason to assume that there’s any problem with your gut at any level, either with the lining of your bowel or with your bowel bacteria or with any part of it. The problem with gut health as such, this sort of new idea that the bowel flora and the gut itself is responsible for more than meets the eye, is a relatively new concept. So trying to translate those initial research ideas and theories into guidelines for how we treat patients and how we advise people with lifestyle is still a ways off, in our opinion.

Generally speaking, from a medical practitioner’s point of view, we try to rely on evidence-driven medicine for the most part. When we’re not relying on evidence-driven medicine, we should tell people that this is all theoretical. A lot of the things that are happening in this space are still all, to be honest, Nick, very theoretical in nature, although there is accumulating evidence for its benefit. For example, the first point is what changes in bowel flora are actually important and what aren’t? That question hasn’t been answered yet. Neither is the question of how you should even measure the bowel flora. That question hasn’t been perfectly answered either. Therefore, trying to taLk about it beyond that is all very highly debatable, if you like.

Nick: I see. So I’ll jump in. You’ve mentioned bowel flora. There might be some people in our audience who don’t really know what that means, so do you want to touch on that?

Nathan: Okay. So traditionally, bowel flora refers to predominately the bacteria that make up the organisms that live in your bowel. Our bodies, we share, if you like, with bacteria, also probably viruses and yeasts and fungi and other things as well, but I’ll focus mostly on the bacteria. For example, there’s bacteria in your mouth, there’s bacteria on your skin, there’s bacteria just about everywhere you look. And those bacteria initially were thought to be harmful, and then we moved to thinking that they were benign, to now thinking that these bacteria are actually vital to human health, and when these bacteria get disturbed, it causes human disease. There are many, many examples of how this happens.

But the bowel flora consists of about a kilogram of bacteria that inhabit predominantly the large bowel. The small bowel also has its own flora, as does the esophagus and the mouth. But predominantly, the mass of the bacterial flora found in the large bowel, which is the six feet of bowel between the small bowel and the anus, if you like.

Nick: Okay. So when we’re talking about … I guess we should maybe address if someone is concerned about their gut or they, just out of curiosity, they want to measure their gut health, how could they do that? Are there tests or what would be the best way to test your gut health?

Nathan: In terms of the bacteria, if you’re referring to the bowel flora as being what you’re referring to, then there is no actual … I will preface this by saying there’s no actual proven method to do it that correlates with an outcome. If you like, no one has said, “If you’ve got this particular bowel flora, you’ll live till you’re 100,” or, “If you’re got this particular bowel flora, you will not get bowel cancer,” if you know what I’m saying. Having said that, probably the best test available to actually try and measure the bowel flora are tests based on the RNA, which is like DNA, but bacteria have.

Nathan: You can actually measure the RNA and measure the preponderance of certain bacteria in the gut. One of the tests that we use is called a uBiome test. But basically, they’re all the same. These tests are what’s called r16 ribosomal subunit test. They actually can give you, off a swab of your toilet paper, the relative abundance of various bacteria in the gut. It’s a very, very accurate measure of what bacteria you have and what you don’t. The problem is, is determining what that means to the individual. What does it mean that you haven’t got any bacteria of a certain type, or what does it mean that you’ve got too many of this bacteria? That’s what hasn’t been worked out yet. But the way of measuring it has, generally speaking, been worked out, and the vast majority of research projects on this problem are done using this r16 ribosomal subunit test, which is available to your average person if they would like to do it.

Nick: I see, okay, so it’s quite easy, then, to get tested, but understanding the results is still an area where research is being done.

Nathan: Every day, I get people coming in with their r16 ribosomal subunit test of various types asking me what it means, and I preface that by saying in the vast majority of cases, we don’t know what it means. What I can tell you is that in certain diseases of the gut and outside of the gut, there have been associations with a particular bowel species and there have been associations with especially decreased bacterial diversity. What that means, and your listeners might hear this not infrequently, are bacterial diversity, if you like, refers to having lots of different kinds of bacteria, rather than just one or two. It’s a bit like a zoo where you have elephants and lions only, versus all the other animals you usually find in the zoo. That absence of diversity has been associated with a number of diseases both inside the gut and outside the gut.

Nathan: These tests that we do on people, they do measure diversity and they also measure very well the presence or absence of the probiotic species, the good bacteria, if you like, some of the bifidobacteria, the lactobacilli, [inaudible 00:10:44], all these kind of bacteria that are thought to be of benefit to human health.

Nick: I see. You’ve just mentioned probiotic, and so often in supermarkets or health stores, we’re seeing a lot of products like probiotic yogurt or drinks like kombucha. What’s your take on these commercial health products or these commercial gut health products?

Nathan: Because of an absence of what we call Grade 1 medical evidence, which is where the things have been subjected to stringent testing and the way we do clinical trials with drugs, I’m somewhat skeptical, I must admit. Probiotics have been fairly extensively looked at, and the results of most probiotic studies are quite disappointing. In clinical practice, I’ve never been particularly impressed by the results of using them, but overall, if you look at the study results, the study results are generally quite disappointing as well. When you subject them to very stringent, large placebo control crossover trials that are properly blinded and done and a sort of a drug manner, they generally have been disappointing. There’s even some evidence that certain probiotic strains, when they inhabit the wrong part of the gut, can actually be bad for you.

Nick: I see.

Nathan: These bacteria make things, you see, Nick. They make substances that can affect people, and that’s the way it works. So you have to be careful that they don’t cause harm, either. As for the foods, the foods are what we call prebiotics. They actually change the bowel flora, and this has been proven. They do change the bowel flora. I have much more of an interest in a prebiotic approach than a probiotic approach, because changing the diet will change the bowel flora significantly. This is another ongoing area of interest, especially in research-land in regards to how you change your bowel flora to a more beneficial type by changing your diet. So much more prone to believe in that part of it than the actual probiotic part. I think putting one bacteria into the small bowel, I don’t think that generally makes a whole lot of sense, but the prebiotic approach does.

Nick: Okay, so it’s far better to do some research into your diet and look at maybe eating healthier food rather than spending money on kombucha or probiotic yogurt and eating or drinking that every day.

Nathan: I don’t think there’s any … I don’t have a problem with people having a prebiotic diet. If you’re going to have a prebiotic diet in our society, which is very fast-moving and everyone’s busy, trying to put together your own prebiotic diet without any assistance from supplements might be quite difficult for your average person.

Nick: Okay.

Nathan: I don’t have an issue with eating those things at all. The only thing I would add or say is that these things have not been proven to have clinical outcomes. That’s the only thing I’ll say. Now there’s lots of good theory behind it, and that’s all fantastic, and there might be some laboratory data based on animals having this or that, but what is proven is it will change your bowel flora. The question is how does it change bowel flora, what does it change bowel flora to, can you predict what’s going to happen, and most importantly, is what benefit is proven to happen from that when you do it? That clinical outcome part of it has not been proven.

For example, they’ve looked at diet in people with inflammatory bowel disease, people with Crohn’s or ulcerative colitis, and there’s not a lot of evidence that any particular diet is of any particular benefit. There might be some minor improvements around certain diets, but this idea that you can cure your inflammatory bowel disease with diet has certainly not been proven for the vast majority of patients. So you need that clinical outcome. You need to have the evidence that these things actually work, before we, as doctors, can be adamant that patients change their diet or take a probiotic or a supplement to control over their gut disease or disease outside of the gut.

Nick: I see, and as you mentioned, you’re sort of still waiting on the research or evidence, even in relation to diet.

Nathan: This is a huge space in research-land. This is predominantly not just gastroenterologists investigating this. This has been directing research for many different groups of researchers, from basic scientists all the way through to immunologists and infectious diseases experts. There’ve been more studies published on the gut flora in the last three years than have ever been published on the subject in the past, so the evidence will come.

What we need is very big population-based studies of bowel flora and how it changes over time, and what the clinical outcomes from that are, what correlates with having a good bowel flora in terms of health and what correlates with having a bowel flora. For example, there’s a very big study happening in Belgium and Germany at the moment, looking at bowel flora and inflammatory bowel disease. The results of that will be fascinating. We’re talking about thousands of patients, or thousands of people being tested sequentially over time. So how stable is the bowel flora and how does the change correlate with the change in health?

Nick: Okay, so with all these books coming out, obviously it’s very good to self-educate and learn, but people should just be mindful that at the moment, there really isn’t any published work that’s proving a certain diet has an influence on a positive or maybe even a negative influence on gut health.

Nathan: No there isn’t, and I think when reading these books or reading articles or things on the internet about this, it’s very important to see who’s writing the article, what’s the name of the article, and also whether anything’s referenced or not. When writing an article on these issues, really, the articles should be referenced, meaning that there should be some note at the bottom as to what studies or what sources these recommendations have come from.

Nathan: Having said that, Nick, though, I don’t think that means we shouldn’t start doing things now. I wouldn’t want to ever suggest that people shouldn’t try to live healthily, I just think that doing unnatural things, i.e. not eating a whole food group, for example, in the belief that it’s going to benefit your gut health and therefore your general health, I wouldn’t advise that. But certainly, trying to have a diet that’s much higher in fresh foods, especially fruit and vegetables, avoiding processed foods, trying to have a high-fiber diet, I think all of these things are fairly simple, and people understand. I think it’d be better to get that message through to the population rather than trying to proscribe one particular diet that has gotten a lot of evidence for its use.

Nick: Sure. Okay, so we’ve touched on diet. Other than diet, what other factors can influence the gut negatively or poorly?

Nathan: Well clearly, the most obvious one is antibiotic therapy. That includes possibly antibiotics we’re exposed to which we don’t even we’re being exposed to. But predominantly, I think it’s well recognized now that antibiotics are overused, and a lot of the patients I see do blame their gut illness or their outside the gut illness on having had antibiotics in the past.

If you like, I use the analogy that the gut is a bit like an environment, like an ecosystem, where certain species can go extinct if you push them too far. Antibiotics do that. They do push around the bowel flora, and it’s quite easy to, what I call euphemistically, break your bowel flora. You push it to a point where they don’t recover, and that is pretty commonly seen, and that’s one of the usefulness of this test I was referring to, the r16 ribosomal subunit test, is it can tell you if you’ve pushed your bowel flora over the edge.

So antibiotics is one thing. Diet is clearly another, which we discussed. The association with stress is unknown. You always wonder whether it’s stress causing the bowel flora change or whether it’s the bowel flora change causing the stress. You never know which way it works. But certainly, that could play a role. Also, exercise might play a role, and general lifestyle factors. Smoking and drinking would almost certainly negatively impact. There are studies suggesting that as well. Medications might negatively impact too, especially medications that do affect digestion of food and also gut motility might, which is why the gut moves might [inaudible 00:19:29] bowel flora. So there’s lots and lots of factors.

Nick: Well I think this has been a great introduction to gut health, so I think we’ll start to wrap up this first podcast. Next week, we’ll be discussing a fairly interesting topic, which is FMT. So do want to touch on that treatment?

Nathan: Yeah, so FMT, I mean, people try to make it very complicated, but in the end, it’s quite simple. You assess a person as having a bowel flora that’s not right or it’s broken, and you fix it by not just replacing one bacteria or even just bacteria at all. You do it by replacing the person’s stool, if you like. It’s a very old treatment. It’s been around for more than 2,000 years. I think it was invented by the Bedouin camel drivers, but you basically just replace the entire bowel flora, with the hope that that will restore normal gut health and therefore fix the person’s medical problem.

Nick: All right, we’ll get into that topic next week. So thank you very much for your time, and this is actually your podcast. Let’s wrap it up. Nicole, did you want to add anything or say anything?

Nicole: Nope. I’m looking forward to next week’s podcast on the FMT as well, so no, thanks Nick.

Nick: This episode of The Holy Gut podcast was sponsored by the Moonee Valley Specialist Centre. For more information about Nathan and Nicole, please visit If you have any questions related to gut health that you would like answered on the podcast, please let us know via the contact form at

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