Dr William Davis – Understanding The Gut-Skin Axis

Content by: Dr William Davis

Watch the full interview below or listen to the full episode on your iPhone HERE.

Stu: This week, I’m excited to welcome William Davis to the podcast. Dr. Davis is a medical doctor, expert in gut and heart health, a New York Times bestselling author of 10 books, including the Wheat Belly Series, with nearly 4 million copies sold. He’s a leading expert in nutrition, and in this conversation, we discuss his investigations with L-Reuteri, a well-studied probiotic and its connection with skin health. Over to Dr. Davis.

Audio Version

Some questions asked during this episode:

  • How long might we see improvements in skin health with the right gut protocol
  • What type of diet/foods would you recommend with skin health in mind
  • Tell us about your investigations with L. reuteri (roy-ter-eye)

Get more of Dr William Davis:

If you enjoyed this, then we think you’ll enjoy this interview:

Dr William Davis – Lose The Wheat And Find Your Path Back To Health
HealthMukti Organics – Discover the Benefits of Natural Skincare
Dr Christiane Northrup – Unlocking the Key To Vibrant Health

The views expressed on this podcast are the personal views of the host and guest speakers and not the views of Bega Cheese Limited or 180 Nutrition Pty Ltd. In addition, the views expressed should not be taken or relied upon as medical advice. Listeners should speak to their doctor to obtain medical advice.

Disclaimer: The transcript below has not been proofread and some words may be mis-transcribed.

Full Transcript



Hey, this is Stu from 180 Nutrition, and welcome to another episode of the Health Sessions. It’s here that we connect with the world’s best experts in health, wellness, and human performance, in an attempt to cut through the confusion around what it actually takes to achieve a long-lasting health. Now, I’m sure that’s something that we all strive to have. I certainly do.


Before we get into the show today, you might not know that we make products too. That’s right, we’re into whole food nutrition and have a range of super foods and natural supplements to help support your day. If you are curious, want to find out more, just jump over to our website. That is 180 nutrition.com.au and take a look. Okay, back to the show.


This week, I’m excited to welcome Dr. William Davis. Back to the podcast. Dr. Davis is a medical doctor, expert in gut and heart health, a New York Times bestselling author of 10 books, including the Wheat Belly Series, with nearly 4 million copies sold. He’s a leading expert in nutrition, and in this conversation, we discuss his investigations with L-Reuteri, a well-studied probiotic and its connection with skin health. Over to Dr. Davis.


Hey guys, this is Stu from one 180 Nutrition, and I am delighted to welcome back Dr. William Davis to the podcast, Dr. Davis. How are you?

Dr Davis


I’m terrific. Stuart, gladly back.



No. Thank you so much. For everyone perhaps out there that may not have listened to our first conversation, not familiar with you or your work, I’d love it if you could just tell us a little bit about yourself, please.

Dr Davis


Well, I started very conventionally, Stuart, practicing cardiology, this thing called interventional cardiology where you abort heart attacks and put stents in, drill out people’s arteries, those kinds of things, blockages. But I had an odd turn in my life, and that was my mom who was living in New Jersey at the time. I had just moved to Milwaukee, Wisconsin, about a thousand miles away, and I got a call that she died suddenly about four months after her successful two vessel coronary angioplasty. In other words, she died after a procedure that I was doing. I didn’t do my mom’s of course, but I was doing that simple kind of procedure every day, many times a day.


But it was a vivid illustration, Stuart, of how fruitless, how pointless, how dangerous it is to try to manage a disease like heart disease in an laboratory, in a cath lab. Because many people, as you know, you’ve heard these headlines, many people never survive who get to the hospital. They die at home or route. And so I asked this question, this is now back 30 years ago, I asked, could we have identified my mom being at risk a year ahead of time, five years, 10 years? Well, back then, we all thought cholesterol was that tool. Of course, it’s proven to be a miserable failure as a preventative tool, though a wonderful source of revenue for the pharmaceutical industry, and they’ve managed to brainwash an entire generation of physicians into thinking that cholesterol and statin drugs are the cure for heart disease. Of course, they are not. They’re not even close. They’re barely having any impact at all. That’s why in the U.S., 80 million people, Stuart, more than 80 million people take statin drugs, and there’s been virtually no impact on the incidence of heart disease.



My word.

Dr Davis


But anyway, so back then, so I wanted a better tool. If you have a total cholesterol of 230 milligrams, are you going to die of a heart attack tomorrow? Never. Six months, you can’t tell from that garbage measurement. This was true back then, it remains true today though there’s some further refinements, but still remains largely true. A simple CT heart scan to generate a coronary calcium score is a extremely reliable predictor of your future in heart disease, normal is zero. We quantify calcium because it occupies 20% of total atherosclerotic plaque volume. People say, “Oh, it’s only hard plaque.” No, it’s total plaque. Soft, fibrous, hard, all its elements. So it’s like a dip stick or a gauge of how much plaque you have in your arteries.


Well, I helped open a place we called Milwaukee Heart Scan. It was the first scanner in Wisconsin, one of the first in the Midwest, and we started scanning people left and right. And Stuart, when you look for heart disease, hidden heart disease in people like you and me going to work, riding our bikes, going for walks, feeling fine, no symptoms, no chest pain, no breathlessness, no heart failure, just going about your business, you still find heart disease hidden there. Like my mom may have been say five or 10 years before her event, but what do you do about it?


Well, we help publish these data. If you have a score of let’s say 300, which is an important score, zero normal, the higher the score, the more danger you’re in. Of course, my colleagues will say, “Well, what score do you need a procedure?” None. There’s no such score, but it’s done all the time because it makes a lot of money. Let’s say your score is 300, and you did nothing, which of course nobody would do nothing, but if we did nothing, it would go up about 25% per year. So 375, 480, whatever, five. And with each increase, you get closer to death, heart attack, need for procedures because of the appearance of symptoms.


Well, what happened? So this is 30 years ago, what happened when you put somebody on, what is, even today, Stuart, is still called optimal medical therapy. Baby aspirin, high dose of a statin cholesterol drug, a low fat, low saturated fat diet, rich in healthy whole grains, exercise program, et cetera. How fast does the score go up? 25% per year. By this measure, has zero impact, no effect whatsoever. Yet they call it… It’s almost comical, optimal medical therapy. It’s like saying, “I have an antibiotic for your pneumonia.” “Does it work?” “Oh no, it doesn’t work. But take it anyway.”


But they need it and they do at the street level, Stuart, I got people freaking out on me. Scores are going up, they’re getting closer. Of course, my unscrupulous colleagues would say things like, “Wow, let’s do the real tests.” The heart catheterization. You need a preventive stent or bypass, which by the way, you cannot justify it. People do not benefit when they’re going about their business with no symptoms and have a procedure like that, but it’s done all the time because it pays so well. And so I had the zigzagging, go through a process of trial and error looking for things that had an impact.


One of the lessons learned many years ago was that when you add vitamin D, particularly in this climate where I’m in a very northern climate, I’m in suburban Chicago now, but I was in Milwaukee then, just another 60 miles north where it’s cold and the sun is weak. And even in the summertime, people wear clothes. And of course modern people tend to work indoors nowadays. And also as we age, we tend to lose the capacity to activate vitamin D in the skin. So I added vitamin D. Stuart, it was the first time, rather than seeing 25% per year increase by doing some things, we got to slow it down in some people, 8%, 8%, 12%. We added vitamin D, it was the first time I saw scores plummet. A score of say 480 would be a score of 235 or something like that. And at first, I didn’t believe it.


I went back and looked at the scan before and after, and you can see the calcium did shrink. And even though the device is meant the detect and quantify calcium, you can still see some of the softer elements. And you could see there was visible shrinkage of plaque, and that was just vitamin D and led to some other lessons. One of the things I did back then was reject this ridiculous measure called cholesterol and go instead to the next best test, which is advanced lipoprotein testing, it shows the particles in the bloodstream that cause heart disease that cholesterol was meant to indirectly reflect. So instead of doing cholesterol, we did lipoprotein using a method called mostly nuclear magnetic resonance, NMR. All that means is taking a clear part of your blood, putting in a magnetic field, and refract it. It separates your particles and gives you a reading of what kind of particles are in your plasma, the clear part of blood.


And it became clear that heart disease has nothing to do with cholesterol, has everything to do with a number of measures, but by lipoproteins and excess of small LDL particles, not LDL cholesterol, but the actual particles that contain cholesterol and other things. So if somebody had a positive coronary calcium score, say of 500, they invariably have a really high number of small LDL particles. Small LDLs, really unique particles, Stuart, they’re much more persistent, last five to seven days in your bloodstream rather than 24 hours of a large benign LDL particle. They’re very adherent to arterial walls. They’re much more prone to oxidation. They’re much more likely to provoke inflammation in the wall. So it’s this perfectly crafted little monster to create coronary plaque.


And it became clear, all these people, as well as people with stents and heart attacks, would have something like 1,800 or 2,400 nanomoles per liter, part of count per volume of small LDL particles. Well, there’s science, even back 25 years ago, it was well sorted out. I asked, what foods provoke formation of small and what other factors? The only foods that caused formation of small LDL particles, wheat, grains, and sugars. So I asked people to say, “Hey, let’s forget this nonsense about cutting out fat and saturated fat. Let’s instead take out the thing that causes small LDL particles.” People did it, and their small LDL particles would drop typically from 2,400 to zero.


It was obliteration, elimination, not just a little improvement, but this is when they started telling me all these crazy stories. I didn’t know what to make of it at first. You didn’t tell me I’d lose 63 pounds and eight inches off my waist. You didn’t tell me that my rheumatoid arthritis would be 80% better, I’m off three drugs. You didn’t tell me my depression would lift, my psoriasis would get better, my eczema would get better. I had no idea why. Why would removing the food advocated by all dietary agencies, government agencies, otherwise, why would removing that food generate astounding improvements in health? And that was the launch of a whole Wheat Belly idea, because one of the things I asked was why And when I started to talk to agricultural scientists and geneticists who were in the business of generating the wheat plant, for instance, it became clear that they had changed it dramatically in the 1960s and turned something that was a problem for human health into an enormous poison for human health, including provocation of small LDL particles.



Oh my word. That is absolutely fascinating, and I’ve been following this journey for a long time, and certainly, I’m 50 now, so I would sit in that gray area of the time, I think if things are going to start to go wrong, then they could start now, possibly earlier. But on my 50th birthday, I got the coronary arterial plaque scan on the heart and came back with zero. So I thought, “Well, that’s-”

Dr Davis


Oh, great.



That’s a good thing. But probably from the day that I purchased and read the Wheat Belly book, it made so much sense, especially when you were talking about the way that the wheat has been changed over the years for profit and for increased yield, where it can now grow underwater and be harvested in a more efficient way and how chromosomes have changed. And I think that was probably the last time I had a slice of bread or anything that contained any of those grains, and I’ve never looked back. And it makes me think, how well can the human body function when you give it the right raw materials? Because I have heaps of energy, I do a lot of stuff. I have freedom from food. No cravings, no snacks or any of that because I haven’t got the blood sugar highs and lows.


And a lot of people that I see that do adopt the whole food approach to diet and remove the processed grains and packaged and processed foods really do thrive. For all of our listeners that haven’t listened to that particular podcast with you that we recorded a while back, I would absolutely recommend it because it’s such a necessary cog to turn in your mind, to think about how you think about the foods that you eat and what they do to you. But I’m a complete advocate and have been living that way for over a decade. So I completely agree with everything that you’re saying, and it’s fascinating. I love the journey that you’ve done, and I’ve looked at all of the testimonials and the videos, and all of the content that’s come out of that message from you. And it is nothing short of life changing for so many people.

Dr Davis


It’s become clear. Also though, Stuart, in a modern life, we need to also accommodate or adapt to the nutrients missing from modern life. Now, there’s a lot of them, but there’s four that I focus on just because when corrected… So one of the things that happens to people who consume grains and cut their fat, all the nonsense dietary advice is they develop insulin resistance. In the U.S., it’s wildly out of control. Two thirds of the population, including children and teenagers, have insulin resistance. That’s the process of course, that leads to type two diabetes, hypertension, coronary disease, heart disease, dementia, cancers, obesity. So it’s a very fundamental process.


And if we can get rid of or reverse insulin resistance, you have a major control over her health in a whole wide variety of ways. And so there are four nutrients that I focus on, very easy. Omega-3 fatty acids from fish oil, iodine, magnesium, and vitamin D. Their need are programmed into your genetic code. You need them. And when you get them, you have marked reduction in insulin resistance, and it allows you to further lose visceral fat, abdominal fat, and reverse such things as high blood pressure, small LDL particles, risk for Alzheimer’s, et cetera. So diet is extremely powerful. But in the modern world, to compensate for all the things we’ve done wrong, like you have to drink filtered water, it’s not a choice. Water in the river or stream has magnesium, but it has sewage and runoff too. So we have to filter the water, but water filtration removes all magnesium. So we’ve got to compensate. That’s just one example of one of the nutrients you have to make up for.



Yes, it’s fascinating. And also on that tap water topic as well, we have an under sink filter here that removes a whole heap of stuff because I had a conversation with a gut health specialist sometime back, and they said, “Well, don’t forget that the majority of the tap water in your country is chlorinated and chlorine is a very effective antibacterial agent.” And of course, our guts thrive on the right bacteria, and so we drink gallons of this stuff without even… An alarm bell or a light bulb just lit in my mind when she said that. And I thought, “I’d never actually thought that. Of course, drinking liters of chlorinated water every day probably isn’t the best method to support my gut health,” which we’ll talk about in a second, is the cornerstone of health as well. So it’s an and eye-opener.

Dr Davis


We’ve traded cholera for disruption of the intentional microbiome and mucus barrier, exactly right.



Yeah. So just on that then, in terms of gut health, because you mentioned those four nutrients that are super important, but if we’re still on the processed carbohydrates, refined grains train, and it is impacting the integrity of our intestinal lining and things like that, surely then that we’re not going to be able to absorb the nutrients from the stuff that we actually need in the first place without correcting or addressing our gut health. Would I be right in thinking that?

Dr Davis


Yeah, I think you’re right. The average Australian or American or European… Little less so European, but diet is so destructive for so many reasons. The Amylopectin A of wheat and grains, that’s the carbohydrate you need in wheat and grains raises blood sugar sky-high. Just that alone has an impact both on the body itself, of course, as well as the gastrointestinal microbiome. The irritants in wheat and grains, there are numerous bowel irritants. Wheat germ agglutinin, for instance, not gluten, but wheat germ agglutinin. It’s called agglutinin because when it contacts red blood, it causes agglutination or clotting. And so wheat germ agglutinin is a very potent bowel toxin. When you inflame the intestinal wall, it changes the bowel floor composition and erodes the protective mucus barrier. Lots of sugars in the diet is an invitation, for instance, for proliferation of fungal species like candida species. On and on and on. There are many, many problems with the modern diet that cultivate, among many other things, a disruption of the intestinal microbiome.



Okay. And I know I’ve got a fair few questions that I’d love to ask you about the skin and the nutrients that are required to support skin health and also microbiome, and how that’s connected. And so the term gut skin access, what does that mean for our listeners and me, and why is it important for skin health?

Dr Davis


It’s proven to be extremely important and extremely powerful, but sadly, Stuart, not all the details have been worked out, but there’s a number of means by which microbes in the GI tract affect the microbes in the skin and the composition of the skin. So one way would be as you know, I play a lot with this microbe called lactobacillus reuteri because if we believe the evidence in animals that came out of MIT, Massachusetts Institute Technology, L-reuteri takes up residence in the GI tract, sends a signal via the vagus nerve in the chest to the brain to release the hormone oxytocin, and oxytocin exerts numerous effects on the skin. In animal studies, increase in the thickness of the dermis because of deposition of collagen. So the marked increase in thickness of the dermis such that you get the smooth skin of a youthful mouse.


It increases the sebum production, that’s the moisture effect on skin. It accelerates healing of skin wounds. So dramatic effects via oxytocin, but there’s also metabolites being produced by microbes that benefit the skin. These are metabolites like butyrate that have all kinds of wonderful effects like reduction of blood sugar, deeper sleep, vivid dreams, but also effects on the skin. The process, it’s not quite clear how this happens, but it can change the skin microbiome also. Someone with eczema for instance… Healthy skin, one of the dominant microbes is staphylococcus epidermidis. But when you have eczema, there’s a shift towards a relative called staphylococcus aureus, which most of your listeners know is a pathogen. It’s not quite clear how causative it is or whether it’s just an accompaniment, but it’s clear there’s a shift in microbiome composition of the skin.


Another means by which the microbiome impacts the skin is this process called endotoxemia. All that means is in so many Australians, so many Americans, other people, because of the things we’ve been exposed to, like chlorinated drinking water, as you point out, overuse of antibiotics, other prescription drugs like stomach acid blocking drugs, anti-inflammatory drugs, synthetic sweeteners like aspartame, emulsifying agents like carboxymethyl cellulose, polysorbate 80 that disrupt the mucus barrier, on and on. Long list of things we’re all exposed to as modern people, and it’s caused the loss of hundreds of beneficial species in the gastrointestinal microbiome. Well, those were species that suppressed unhealthy, mostly fecal species. And so what’s happened to a lot of people, by my estimation, one in two people, fecal microbes have proliferated because they’re not being suppressed by those favorable microbes. And in many people, those fecal microbes have ascended into the 24 feet of small intestine, stomach duodenum, jejunum and ileum.


Now, the small intestine is ill-equipped to deal with fecal microbes. It only has a thin single layer of mucus barrier to protect your intestinal wall, unlike the colon that’s well-equipped to handle fecal microbes, a think two layer of mucus barrier. So when these fecal species get into the small intestine, and these microbes don’t live very long, they live for a few hours. And so there’s trillions of microbes in the 24 feet of small bowel turning over very rapidly and dying. When they die, they release some of their components. And one of the most important components, something called endotoxin in their cell walls. Well, that endotoxin can get through the small intestinal barrier and into the bloodstream. And when endotoxin enters the bloodstream, it’s called endotoxemia. And that’s a relatively recently discovered process that many of us suspected, but it finally was validated by European group. And then since corroborated numerous times.


That’s the process that tells us how and why microbes in the GI tract can be experienced as skin rashes, like rosacea or psoriasis or in the brain as dementia or depression or Lou Gehrig’s disease or Parkinson’s disease, or in joints and muscle like fibromyalgia or rheumatoid arthritis, or as metabolic diseases via the bloodstream like obesity and type two diabetes and hypertension. So you can see the entire landscape of human health has to be redefined, reconsidered in light of the contribution of and including the skin, the contribution of the gastrointestinal microbiome. So there’s several routes by which the gastrointestinal microbiome can impact skin health.



And this is definitely a topic of confusion for so many people because they understand that gut health is now important, and so perhaps they do one or two things. They might rush out to the chemists and buy some off the shelf probiotics, or they might go into the supermarket and get some fermented goods. So maybe some kimchi, some sauerkraut, some kefir, maybe kombucha, and they don’t have any success with either of those. And you mentioned this L-reuteri as well. So how important is that in the mix of things? And if our shop-bought probiotics are not working and our shopping bag full of fermentables is not working, what would we do?

Dr Davis


Well, I think they’re on the right track, but they’re just unsatisfactory solutions for a number of reasons. So commercial probiotics, we call them probiotics 1.0. It’s the first group of commercial products. They’re created in a haphazard way. Let’s throw a little bit of bifidobacteria bacteria, let’s throw a little bit of lactobacillus acidophilus. There’s no consideration of what’s called consortium effects. Microbes are just like humans, we don’t live in isolation, of course. We have a partner, families, children, coworkers, neighbors, communities, microbes are the same way. They collaborate within communities. And if all you do is make a haphazard collection of microbes, you’re not going to get much of an impact. Another thing is the technology isolates some of the microbes we’ve lost or are lacking like a very, very important microbe is faecalibacterium prausnitzii. I’m sorry, Stu, I don’t make these names up.



I wouldn’t want to spell it.

Dr Davis


Very important microbe. But if you put it in a probiotic capsule, it dies. It’s called an obligate anaerobic, it dies upon exposure to oxygen. So the current crop of commercial probiotics, not very helpful. It’s going to get better. There’s some technologies are emerging to encapsulate those anaerobes. There’s some groups are working on these collaborative effects because one of the pitfalls of probiotics is if mom gave you a microbe when you were a baby through breastfeeding or patches of the vaginal canal, you’d likely have it for a lifetime unless it got wiped out by an antibiotic or something like that. But you potentially have it for a lifetime. But if you take it as a probiotic, it’s good for maybe a few days to weeks. Well, what’s the difference? Probably the community, the milieu, the environment’s entering, that you don’t restore the entire community, it’s only going to take up temporary residence.


And by the way, the probiotic market has become very competitive. So a lot of gimmicks going on too now, a lot of crazy claims like you must take spore forming microbes from the soil. That’s nonsense. There’s no truth to that at all. And so beware of marketing claims to cover up the deficiencies of modern, it’s going to get better. So as time goes on, that industry will smarten up and come out with better products.




Dr Davis


Another problem with the commercial fermented foods is if you and I had a shoe factory and it took us seven days to make a pair of shoes and a factory opens up down the street, they can make a pair of shoes in four hours. Who’s going to make more money? Same thing with fermented food. So you’re going to have to fermented for days to weeks or you just abbreviate it, ferment it in maybe 24 hours, you’re going to cut corners and ferment it for as short time as possible. So what I tell people to do is if you buy a fermented food, whether it’s a yogurt, kafir, kombucha, whatever, let it sit in your kitchen counter for at least a couple of days, let it ferment further. And the other thing is, of course, commercial manufacturers, they want control the microbial species often, they don’t want any.


Once in a great while, there’s an episode of food poisoning, for instance, because you ate fermented meat like let’s say from Spain, and it was air fermented with microbes resident in the air or surfaces. It sometimes acquires a pathogen like listeria or staphylococcus, and people get sick. So what they do now when they ferment things like meat and other things is they inoculate with known bacteria, so it controls what’s growing in there. But it also means they tend to inoculate only a few species. And so you’ll get that full bloom, that array of healthy species that occurs naturally when you ferment. But you still can do okay with commercial fermented foods. But still, as you would point out, it’s still the best to ferment on your own, to chop up some veggies in brine and non-iodized salt and let it ferment on your kitchen cabinet. It’s so easy, it’s virtually without cost except for the veggies. And you get that kind of bloom of all kinds of important microbes.


Some of the most important microbes for gastrointestinal health come from fermentation like Leuconostoc mesenteroides and Pediococcus pentosaceus and some others. These are very, very important microbes. And the interesting thing about fermenting microbes, if we believe the work of Justin and Erica Sonnenberg from Stanford, the husband and wife team, is that fermented foods, those microbes aren’t the ones that take up residence. They somehow set the stage for other beneficial microbes either to reenter or bloom. No one knows where they come from, but somehow, just those fermenting microbes allows a whole panel of other beneficial microbes to take root.



So biggest bang for buck then, because you’ve mentioned lactobacillus reuteri, and then we’ve heard about all of the usual suspects from a bacteria standpoint in terms of the yogurts that you can get from the supermarket and also a lot of the bacteria that are found in the fermentable foods as well. Where is the biggest bang for buck and is it important to be specific to the individual or is it just good to get a whole heap of the bacteria that just will work for everyone?


Because I had some testing done years ago, a stool test, and you send it away and your results are input into an app and it tells you what’s going on inside you, apparently. And it said, “Look, it’s very specific. You must take this and you must take that. Don’t ever take that one.” And I had a look, and a lot of the stuff that was in the high street was the one that I was advised not to take, and the ones that I was advised to take were only available through the company that did the testing. And so it’s kind of a red flag there. So what would this consumer do if they want to dodge all of this marketing nonsense and just ensure that they’re doing the right thing?

Dr Davis


Fermented foods are truly among most important things you can do, and a variety of different kinds of fermented foods. A probiotic doesn’t hurt most of the time, it’s just not as helpful as it could be. That’s going to change over time. One of my little pet projects is to identify microbes that appear to be really, really important that we’ve lost. So our friend, lactobacillus reuteri is one of those, it’s very susceptible to common antibiotics like amoxicillin or ampicillin. So if you took amoxicillin, say for an upper respiratory infection 20 years ago, you probably lost all your reuteri, even though it’s present in all indigenous human hunter-gatherer populations. Oh, it’s also present in all mammals. So if we were to sequence the kangaroo or a moose or a deer or a dog or a gopher, they all have reuteri, suggesting it is very important for mammalian health, but we’ve all lost it.


And one of the really important aspects of reuteri besides provoking oxytocin. By the way, Stuart, provoking oxytocin, the hormone of love and empathy at a time, our time of record setting suicide, social isolation, even pre-pandemic, and divorce. So is the loss of reuteri, at least part of it? I think it is because I see it all reversing when people restore reuteri. But another important aspect of reuteri’s behavior and its cousin, lactobacillus gasseri. These are two microbes that when restored, take up residence in the small bowel, actually, the entire GI tract from mouth to anus, very unique. And when they take up residence, they produce what are called bacteriocins. These are natural antibiotics effective against fecal microbes like E-coli and Klebsiella. So I think the broad loss of species like lactobacillus reuteri and lactobacillus gasseri is a big explanation for why one in two people, by my estimation now have this small intestinal infestation or SIBO, small intestinal bacterial overgrowth.


And I’m seeing the restoration, by the way, of reuteri and/or gasseri or even better, both. I’m seeing SIBO recede in a lot of people. There’s a consumer device, I have the old one here called the air device. If your listeners don’t know, it’s a old device. You blow into it, it measures hydrogen gas because microbes in your GI tract produce hydrogen gas, but you don’t. So you can use it to map where in the GI… It’s a consumer device, it’s $200 or so. It’s a little pricey. Talks to your smartphone, zero to 10, amount of hydrogen gas. And you have to use it according to a specific timing. So you can time when you consume something that microbes eat, the sooner you produce hydrogen gas, the higher up microbes are living in your GI tract.


And when this device first came out in 2018, Stuart, I was shocked at how many people tested positive. It was the exceptional person who didn’t test positive. So you might say, well, maybe the device is flawed, maybe the method is flawed. Well, this is also happening. People who had positive, let’s say reading of 10, and then they took some steps to get rid of the presumed SIBO, bacteria in the small bowel. And they would say things like, “Well, it took me a few weeks to get rid of it, but I finally broke the weight loss plateau and lost 30 more pounds or my hemoglobin a1c that was stuck at 6.1% in the pre-diabetic range is now 4.8%.” In other words, I saw what appeared to be the residual health problems after doing everything right, wheat grain elimination, vitamin D, magnesium, omega fatty acids, all that kind of stuff. I saw finally, that residual health problem break and give way. So I became convinced over time.


And all we need to do is look at all the studies, dozens of them, asking this question, what proportion of people with condition blank are positive for SIBO? Not by the air device, they do it formally in a lab or clinic measuring the same gas, hydrogen gas using another device. So one question was asked was what proportion of people with fatty liver, it’s very common, leads to cirrhosis, very bad, are positive for SIBO with several studies, 50%. Well, in the U.S., there’s 160 million people with fatty liver, 160 million. If 50% test positive, that’s 80 million people right there with SIBO. Or ask other questions.


How about people with irritable bowel syndrome? There’s 60 to 70 million people in the U.S. with irritable bowel syndrome, bloating and diarrhea. Well, it varies from study to study, but roughly 40% tests positive. Well, that’s 40% let’s say of 60 million, another 24 million added up through autoimmune diseases, obesity, type two diabetes, pre-diabetes, coronary disease, restless leg syndrome, fibromyalgia. You run through all those, you easily, Stuart, in the U.S. alone, exceed 150 million people with SIBO. Now there’s overlap in obese type two diabetic with fatty liver. So don’t have a precise number, no one’s done that yet, but it’s not a small number. It’s a huge number. It parallels the obesity and overweight epidemic, I think, in size.



So you definitely sold me on the importance of microbiome diversity, and specifically L-reuteri. How do I get it? Where do I get it? Do I get it from food or a pill? Where would we go, because it seems like it’s a no-brainer.

Dr Davis


As much as I hate to say this, one of the things we have to pay attention to when we play with microbes is strain. So my favorite example is E-coli. So I have E-coli, your listeners have E-coli. Well, what if you ate lettuce contaminated by cow manure from a farm with E-coli, you can die of that E-coli. Same species, E-coli, different strain. So we have to pay attention to strain to some degree, and the strain we know does this was the original strain used in those MIT studies, which is called the 6475 strain. And so you can get it as commercial product. It’s called the BioGaia Gastrus, G-A-S-T-R-U-S. Now, those tablets are made for infants, so the dose is very small. They have since come out with a somewhat higher dose, 5 billion per capsule.


One of the big holes in our knowledge, pardon me, Stuart, is what’s called dose response. If you and I had a drug company and we developed a drug, want to know what the best dose is, safest, most effective, we would run through clinical trials and use 0.5 milligrams, 1.0, 2.5, 5.0, 10.0, 25.00 because they have unlimited resources, essentially, and they can test this. It’s very costly to do those studies, by the way. Well, we don’t have that kind of money in the microbiome world and probiotic world. So we typically have at best, maybe two different doses. So we don’t have a lot of awareness. There’s a study that used that strain of reuteri, 10 billion per day, and ladies had half as much bone density loss as ladies on placebo over a year. That’s all they did. No exercise, no vitamin D, nothing. Just get reuteri. 50% less bone loss compared to placebo.


Well, if that’s true of 10 billion. What would’ve happened with a 100 billion? Yeah, nobody knows. We’ll find out with time. We’ve done our own dose response study, limited dose response studies, and I think there is a dose response. Speaking in general, I think most effective doses of microbes tend to be upwards of around maybe in the 30, 40, 50 billion category, you seem to get much more meaningful biological effects. And so the BioGaia tablets originally were a 100 million, which sounds like a lot, but it’s very small when it comes to an adult and bacteria. That was my motivation for making it as yogurt. It’s not really yogurt, it’s nothing like the stuff in the store. The stuff in the store, by the way, is fermented with ho-hum boring micros that don’t really accomplish much. And they use that abbreviated fermentation that hastens production.


We’re going to get micros that are interesting, have unusual beneficial health effects, like reuteri, and we’re going to ferment for a long time, this case, 36 hours. Reuteri doubles every three hours at a 100 degrees Fahrenheit or 37 degrees Celsius. And so we’ll allowed it to double 12 times. We get this really big uptick in count at about hour 30. Now, if you make yogurt in a factory, they ferment for 46 hours. That’s why they get such trivial numbers. So at hour 30, you get this big rise up to 36, we perform something called flow cytometry on our yogurts, and we get something like 250 to 300 billion microbes per half cup serving, and I think that’s part of the reason why we’re getting such a big effect. And we’re seeing that all the effects see in those mouse studies, we’re seeing it play out with the yogurt, smoother skin, reduction of the fine wrinkles, smile lines and crow’s feet, increased libido, deeper sleep, vivid dreams, better empathy for other people, feelings of generosity, acceptance of other people, oxytocin type effects. So we’re seeing that play out in humans with the yogurt.


And I think also a restoration of youthful muscle and probably, though we haven’t measured it ourselves, but then bone density effects also. And so that’s one microbe. So perhaps we picked among the most interesting of all microbes. But that’s just one microbe that achieves all these wonderful effects.



So is that available to purchase now on the shelves in the supermarkets?

Dr Davis


I don’t know what the cost is to you guys, but for us, it’s like $24, something like that, shipping. And then you never have to buy it again because you can make your yogurt from the tablets or the capsules and then you make future batches for a little of the prior batch. It’s very easy. There’s a few things to know. You do need a device that keeps it at about a 100 degrees Fahrenheit. So it could be a yogurt maker, could be a sous vide, that’s my favorite. I have a stick sous vide that works well. Instant pots. Whatever device you choose, it’s always helpful to verify the temperature first. Some of these devices are inaccurate, and reuteri tends to die and a lot of these microbes tend to die about 110 degrees Fahrenheit. So if your device says 104, that would be okay. But you check the temperature, it’s 114, that’ll kill you. It happens once in a while.



Right, right. Okay. And where could our listeners go to find out more information about this? Because I’m sure there’s a whole heap of people that would be absolutely intrigued to learn more about how they could do this themselves.

Dr Davis


So it’s of course in my super gut book recipes, where to source your microbes. Right now, if you’re going to do a multi strain yogurt, what I call SIBO yogurt, Lactobacillus reuteri, Lactobacillus gasseri, and coagulans. By the way, bacillus coagulans is the most delicious yogurt you’ve ever had. It tastes like whipped cream, it’s pretty good. But we co-ferment those. So where do you get them? The hassle is sourcing those microbes for the first time. But once again, you only have to buy it once, make the future. It’s like buying tomatoes. If you plant tomato seeds at the end of the season, you save a tomato for its seeds and you use those seeds. Same thing here. Only have to buy it once.



Got it.

Dr Davis


So it’s all in the Super Gut book. I also have it in my new umbrella website, which is drdavisinfinitehealth.com. It talks about a source of microbes, the recipes, discussions about them. I do this every once a week where I talk to about 80 some people in the audience, and we talk about reuteri yogurt and gasseri yogurt and new lessons learned. But I tell you, Stuart, one of the wonderful things that’s happening is people are fermenting microbes and trying things new. I had a woman ferment lactobacillus salivarius, which I had never done before, which is a oral microbe. And I’ve had people ferment things like lactobacillus fermentum. And what’s happening is a lot of this information came from mouse studies. Well, now we’re doing it. They’re very benign microbes, lactobacillus and bifidobacteria species are very benign. So we’ve never seen any adverse effect unless you have SIBO at first where you can get some bloating or some mental fog.


Putting that aside, there’s no ill effect to these things. And we’re seeing some unexpected effects. I made yogurt, for instance, with lactobacillus brevis because there’s a little bit of information to suggest that species produces something called phenylethylamine, which is a mood booster and nootropic, I wasn’t quite clear on whether it achieved meaningful effects. I think it does though. So we’re seeing all kinds of unanticipated unique effects that even the scientists, the microbiologists didn’t know about.



Yeah, we’ll definitely put those links in the show notes because I’m very, very intrigued to read more about the guide to exactly how to do that from your book as well. We’re coming up on time, but I had a question about your involvement with Oxyceutics because I know that you’ve applied all of your thinking and learning and the amazing information that you’ve managed to collate and investigate over the years into a number of different areas, and I hear that the results are quite astounding. So tell us about that, please.

Dr Davis


Well Stuart, I talk to a lot of ladies and I tell them about the effects of reuteri and other things. And they say, “We don’t care about empathy, we don’t care about muscle, we just want smoother skin.” So I thought, “Well, all right.” And they also said, “We’re sick and tired of making the yogurt” or they’re making other yogurts, don’t want to keep on making the reuteri or they’re traveling. And so they said, “Can you come up with a more convenient way to do this?” So we encapsulated the reuteri and I added some other things that are absent.


I’m a big believer that your body knows how to take care of itself for the most part, and that if we got the nutrients first, if we were living the way we’re supposed to live, a lot of health problem go away. Wheat and grains never belonged to human diet, it was added by mistake about 12,000 years ago. The preceding 99.6% of our time on this planet, we did not consume wheat and grains. We are not adapted to the consumption of wheat and grains. So eliminating that, getting the vitamin D you’re supposed to be getting, et cetera.


But I think the people in the paleo community and some of the other communities are talking about this, we’re lacking collagen and hyaluronic acid in our diets. Because if you went out, of course, if you and I got up this morning and grabbed a club ax or spear and killed something in the outback and opened its stomach, ate the stomach and intestines. Dragged the carcass back, cooked it over a fire, cracked open the skull, ate the brain and tongue and thymus and heart and kidneys, we’d get a ton of collagen and hyaluronic acid. Well, modern people don’t do these things anymore.




Dr Davis


And we have vegetarians of course, say, “Oh no, none.” And of course those things are responsible for skin health as well, by the way is joint health in brain health. So what we’re doing is restoring nutrients lacking in a modern diet. And the Astaxanthin, it’s a carotenoid relative to Beta-carotene, that’s just meant to compensate for the low carotenoid content of modern farmed foods as opposed to hydroponic foods, as opposed to wild plants that are rich in carotenoids, and I think we’re seeing some important effects. We did complete our first human clinical trial with it. Pardon me. We did see an increase in dermal thickness using something called high resolution skin ultrasound. And the ladies, we had a dermatologist researcher do this for us, and they did see increased skin moisture, reduction in skin wrinkles, and a general sense of wellbeing and confidence, I think. I can’t tell that’s from the reuteri or if that’s just because they feel better about their looks or what, but we’re seeing some very positive effects. So that’s called gut to glow to serve ladies who are sick and tired of making yogurt.



Yeah, no, absolutely. And I’m guessing a Google search will present that with the store, the info, the story, all of the above. We’ll drop that in the show notes.

Dr Davis


Yeah, Oxyceutics gut to glow, it’s very easy to find. Great. And it’s the reason why I moved to suburban Chicago, is to support this. We’re doing a lot of research. We’re Very mindful that this is a new area and it’s very exciting, but also want to show real proof. So that’s coming also. It’s hard to talk in detail about what limited evidence we have now in small clinical trials, but we will be pursuing much larger randomized placebo controlled clinical trials to show what these things can do.



Fantastic, fantastic. Lots and lots of information there. So just a final question really before we wrap up, and it’s more personal to you. Obviously you have a ton of knowledge in this particular area in terms of nutrition and health and wellness and vitality. But what are your daily non-negotiables, the things that you do in order to win your day? And they don’t have to be connected with nutrition at all. It may be sunlight first thing in the morning, something along those lines just to get an insight into you personally.

Dr Davis


Sadly, Stuart, I wish it was sunlight, if I lived in your climate. We’ve seen maybe a day of sun the past two months. No joke. So getting sun in this neighborhood’s kind of tough. But you’re right, I would put that on the list. But I make sure I get some source of reuteri until we figure out how to make it take up long term residence, many servings of fermented foods in a variety of ways. That’s important. A variety of different fibers, metabolizable by microbes. These would be very familiar, simple things like onions and shallots and legumes, and galacto-oligosaccharides, legumes. For convenience, inulin powder, acacia fiber, but getting a whole variety.


I try to make it a habit and I tell everybody this, try to get a fermented food and a prebiotic fiber in every meal, every time you eat, make it easy for yourself that way. It’s not hard. It could be as simple as say, having a three egg omelet, just make sure you throw some black beans in there, some chopped onions and a little garlic and you’ve gotten maybe 10 grams or so of prebiotic fibers, but have maybe a little side of kimchi or a sip of one of my favorite little probiotic prebiotic mixes. It’s so easy to make. This is not in the book, by the way, but it’s in my website, Drdavisinfinitehealth.com. But it’s so easy, that I can just tell you.


We take a juice, any juice, but the more pulpy, the better, just provided it has no preservatives like potassium sorbate or sodium benzoate. Empty a capsule of a commercial probiotic, here, it’s called Florastor. I think it’s called something else in Australia, but the microbe is Saccharomyces Boulardii. It’s a relative of Saccharomyces cerevisiae, used to make beer, wine, and sourdough bread. So you can buy it for a few dollars, empty a capsule into that container of juice. Cap it, agitate a little bit to mix, but then uncap it or leave it capped very lightly because at 24 hours at room temperature, you are going to see it bubbling like crazy, producing carbon dioxide.


And if you cap it too tightly, it’s going to explode on your kitchen counter, literally. So we leave it lightly capped and maybe even gas it off every so often. And at 48 hours, you have cut the sugar content by 50% and you have super-duper high counts of Saccharomyces Boulardii, a really important microbe. It’s a fungus, but it tends to have a police cop action on microbes. And it’s the most important thing someone can do, by the way, if you have to take a course of antibiotics. When you take antibiotics, you decimate your GI microbiome and getting Saccharomyces Boulardii has the remarkable effect of preserving most of the microbes in your GI tract even during an antibiotic.



Fantastic. That’s a great tip. Yeah, I’ll be rewinding-

Dr Davis


Sparkling juice.



Sparkling juice, yeah. But with a prebiotic probiotic punch. All of the above. Fantastic. That is excellent. Well, look, I really appreciate this conversation, Dr. Davis. You have been, again, a wealth of knowledge and I’m going to be rewinding and listening to bits for a very long time, so I’ll definitely get this transcribed.

Dr Davis


Stuart, always a pleasure.



Just one-

Dr Davis


Thanks for what you do.



No, thank you so much. I really appreciate it. Just how can our listeners get more of you, so Instagram or all of the channels. Straight to your website I’m guessing, but just for our listeners, where should we send them?

Dr Davis


The Super Gut book is the resource for the microbiome. I almost didn’t include a lot of these comments on diet and nutrients, also just give a quick sketch, but if somebody wants to know what the full rationale is on the diet, there’s Wheat Belly revised and expanded edition that was re-released in 2019. It’s got the full articulation and the science. People often think I made this stuff up, of course I did not make it up. There’s some very good science behind it and a clear rationale. If somebody says, “I don’t care about the science, I just want to know how to do this.” We still conduct what I call the Wheat Belly 10 Day Grain detox program, and we do that once a month for 10 days. We essentially hold people’s hands online and take them through the process, not the microbiome process, the dietary process.


And if you want real handholding and feedback, that’s Drdavisinfinitehealth.com. There’s a very busy, hundreds of thousands of posts on the forum. There’s several thousand blog posts and there’s this two-way Zoom we do, typically once a week for a couple of hours and talk about not just how to get through the program and microbiome, but also new lessons we’re learning. I cringe, Stuart to think, but we were doing even just five for 10 years ago. We were doing a lot of good stuff. But it’s evolved so quickly because I’m a big believer in crowdsourcing wisdom, that when you put a 100 people together all trying to answer the same question, you get answers and you start to figure stuff out. And what I see it happening is the doctors are being left behind in the dust because we’re learning new stuff every time we talk. So it’s a very powerful reflection of this potent phenomenon called crowdsourcing of wisdom.



Fantastic, brilliant. We will put everything that you’ve spoken about in terms of links and all of the above into the show notes. But Dr. Davis, thank you so much for your time. It was a pleasure and I look forward to speaking to you again in the future.

Dr Davis


Thank you, Stuart. Pleasure’s mine.



Thank you. Bye-Bye.


Dr William Davis

This podcast features William R. Davis who is a Milwaukee-based American cardiologist and author of health books known for his stance against "modern wheat", which he labels a "perfect, chronic poison."This view had previously been rejected by the medical and agricultural industry based on conjecture, minimal controlled studies, and... Read More

Want More Articles Like This?

Sign-up for the 180 Nutrition mailing list to receive the latest news and updates.

I agree to 180 Nutrition Pty Ltd Terms of Use and Privacy Policy.