Do Probiotics Really Work, The Carnivore Diet, How To Heal Bacterial Overgrowth, Is Fiber Necessary

I have a master's degree in physiology, biomechanics and human nutrition. I've spent the past two decades competing in some of the most masochistic events on the planet, from seal fit, Kokoro, Spartan Agoji, and the world's toughest mudder to 13 Ironman triathlons, brutal bow hunts, adventure races, spearfishing, plant foraging, free diving, bodybuilding and beyond. I combine this intense time in the trenches with a blend of ancestral wisdom and modern science. Search the globe for the world's top experts in performance, fat loss recovery, gut hormones, brain beauty, and brawn to deliver you this podcast everything you need to know to live an adventurous, joyful and fulfilling life. My name is Ben Greenfield. Enjoy the ride.

Hey, folks, Ben Greenfield here. I have Dr. Michael Ruscio. I can't say his name without trolling the R's, baby. On the show today, one of my favorite guys when it comes to all things gut. We didn't mention this during the show, so I figured I'd mention it now. All of his products, not only his books, but also all the things that he recommends to his patients for things like the elemental diet that we talk about in this show, things to fix ibd, ibs, small intestine bacterial overgrowth. He's cutting all of my listeners at discount, so I'm gonna put that over in the show notes. If you go to the Show Notes for this podcast, Those are@BenGreenfieldFitness.com HealthyGut Speaking of discounts, yesterday was Friday, so I guess you call today Black Saturday. If yesterday was Black Friday, I don't know. But either way, I have a bunch of really good stuff for you over at Kion for Black Friday for enhanced immunity, better recovery, faster muscle gain, faster fat loss. We put together a bunch of bund and then vastly marked them down. We have a coffee bundle. We have a recovery bundle with aminos with Flex with fish oil. We have a life bundle with aminos with the coffee with our clean food bar with Kion Lean, which is the best fat loss supplement that I've ever seen, period. The one that I use every day. In addition, we've got a bunch of gift cards. So if you order over 100 bucks, you get a $25 gift card. You order 150, you get a $50 gift card. I'm barely able to orders over $250. Get a $100 gift card. It's like a tongue twister. So key on Black Friday it goes keeps going all the way through the 27th. So I don't even know what the 27th is. I'm so back ass words with all my travel. I think the 27th is Tuesday. So if you listen to this on Saturday. These specials continue until Tuesday, but of course stuff sells out. So go to getkion.com that's getk I-O-N.com to get on on the Kion Black Friday deal. This PODC brought to you by Gains Wave, which is the bedroom biohack for men and women who want to upgrade their sexual performance. Probably one of the biggest things I noticed was my orgasm length went through the roof after doing gainswave. Like my orgasms last a minute or longer now. It's crazy. That never happened to me before, but I do this Gainswave and they just have a medical practitioner. When you go into the clinic, and the clinics are all over the country, they do pulsating sound waves. So they just kind of wave this magic wand over your nether regions for about 20 minutes. And these sound waves encourage the growth of new blood vessels and that increases oxygen and nutrient delivery to your genitals. I'm just seeing how many different ways I can say nether regions and genitals without saying penis and vagina. But you know, we're all adults here. At least I think most of my listeners are adults. If they aren't, they just learn something new. Anyways, no need for the little blue pills. You just check straight into a Gainswave clinic. You get it done in a they're going to give you something free. You get six GainsWave treatments. They'll throw another one in on the house. If you get 12, you get the 13th for free. To do that, just go to gainswave.comBen that's gainswave.comBen to find a provider near you.

When people ask me the number one book I recommend for all things gut related, it is hands down, a book called Healthy Gut, Healthy youy, Healthy Gut, Healthy youy. It's written by Dr. Michael Ruscio. He's been a guest on my podcast before. We did a big podcast on how to differentiate between all the different types of carbohydrates and what type of carbohydrates were good and what type of carbohydrates were bad on a high carb diet and low carb diet. He also came on and did a big podcast with me a few months ago about why healthy people in particular get broken guts and what to do about it. And I'll link to both of those in the show notes for this episode, which is going to be over@BenGreenfieldFitness.com HealthyGut that's BenGreenfieldFitness.com Healthygut and the reason that I brought Dr. Ruscio back was because at the time I recorded those two episodes, he hadn't yet released this book. He sent me the book and I read it and I've just been recommending it right and left to pretty much everybody who. Well, who has a small intestine and large intestine and asshole and spleen and liver. So if you have digestion, you should read the book. And I actually have a few things. You know, whenever I interview somebody about a book, I don't like to just give you guys exactly what's in the book, but take a deeper dive into some of the things in the book and kind of explore them and unpack them, so to speak. So that's what Dr. Rushi and I are up to today. And Dr. Ruscio's practice is in Northern Cal. You're in which, which city are you in? I forget.

It's Walnut Creek. Right in that. Well, you've had on Judson Brandeis. And so his, his pump kind of male health enhancement clinic is in Walnut Creek as is a cryotherapy center. So we got some stuff to do next time you're in town.

I know that's crazy. Why Walnut Creek? I don't even know why. Why it seems to be such a hot spot for.

Well, it's a nice suburb outside of San Francisco if you're looking to get out of the city but not too far and have kind of like a nice affluent area that's clean and well kept. A lot of people end up in Walnut Creek.

Yeah, that's why there's so many things there. You got a lot of rich bored people. That makes sense. Yeah.

Want to do penis injections and sit in cryotherapy chambers. So I'm one to speak anyways though. So there's so many places in the book that we could start. But where I'd like to start is this concept of bacterial overgrowth. It's probably one of the least understood areas of digestion for a lot of people who get gas and bloating and think they've got whatever, you know, parasites or yeast or fungus or something going on in the colon. But it turns out in some cases it is this thing called bacterial overgrowth. So can you define that? And then I also would like to hear specifically about how that affects the thyroid because that, that was a little known fact to me in the book. So can you get into. Into sibo, or bacterial overgrowth, what it is, and then specifically its effect on the thyroid?

Yeah, I mean, there's a lot there to unpack, which I think is super interesting and very actionable for people. So the inception of kind of my foray into the importance of small intestinal bacterial overgrowth dates back to maybe five years ago, when I think we really saw the initial burst of interest in the microbiota. This is when you started hearing all this cool research being published where African hunter gatherers had more diverse bacteria in their guts, and that seemed to correlate with healthier.

People in general. There's a lot of excitement regarding diverse, healthy intestinal bacteria and the potential utility that we may be able to garner from taking sick people and improving the health of their bacteria. So that was great. But.

What can happen is, when you're looking at things observationally, those observations don't always clearly translate into what you do in the clinic. And so what you were seeing being suggested in terms of inferences, were pretty much the opposite of what any experienced clinician would recommend to do for most patients. And so I was confronted with this.

Quagmire where some of the microbiota research was suggesting we need to undergo all these interventions to increase bacteria. Yet I was seeing so many patients who clearly did not do well with that type of approach and actually only seemed to improve when we underwent interventions, ironically, that would decrease bacteria. And this is one of the things I talk about in the book. When you make a delineation between the large intestine and small intestine, you actually start to sort out where some of these discrepancies come from. And essentially, the long story short is we go to Africa, we do these stool samples of hunter gatherers, and they have really rich large intestinal diversity. But what I suspect is being missed there is the impact of the small intestine, which is much harder to assess. And although, yes, there is a correlation between the large intestine and the small intestine, I don't think we really get a good read on what's going on in the small intestine with a stool test, because it's right in the middle of everything, it's kind of hard to get to.

Yeah. And by the way, I mean, that was like a study just a couple of weeks ago that showed that the bacterial status of the large intestine in no way reflects what's going on in the small intestine, which kind of sucks for a lot of these biome tests that are testing stool and not getting reflective evidence of what's going on up in the small intestine.

Exactly, exactly. And so that's why one of the main premises I develop in the book is.

A lot of the previous gut advice was very large intestine centric. But the problem is the small Intestine represents over 56%. So the majority of your intestinal tract, it's the most prone to leaky gut, it's the most immunoactive, and it's where 90% of your calories are absorbed. So it's a huge miss to miss. The importance of the small intestine is a huge miss. And here's what it kind of bottom lines do. You can twist observations to support almost any hypothesis. Where the bullshit really gets called is when you go to the interventional or clinical trials. And this is why I really harp on the importance of clinical trials. Because you can again, you can cherry pick and mislead with observation data and with mechanism data, but when the rubber really hits the road is when you say, okay, we have a group of 100 people, they are sick. We're going to do this in half, we're not going to do that in the other half, but give them a placebo and then see what happens. When you look at outcome data, you start leaning back toward the interventions that seem to favor the small intestine. So long prelude here to the answer of what is bacterial overgrowth most, namely small intestinal bacterial overgrowth, which is what I think is the most relevant, is where you have either an overgrowth of or the wrong type of bacteria in the small intestine. There should be some, not nearly as much as there is in the large intestine. And what can happen is you can have an overgrowth of bacteria in the small intestine. And again, sometimes it's native bacteria, sometimes it's bacteria from the large intestine growing upward into the small intestine. Sometimes it's oral bacteria from the nasopharyngeal cavity that gets down into the large intestine. Or sometimes it may even be the native small intestinal bacteria that just simply overgrow. But the point is that this is not something like a parasite, which is, I think a lot of the older last generation gut advice was test for parasites and get rid of parasites. And there was some truth to that. And I'm an example of that. I had a parasite, but I think what's much more common now is an overgrowth of bacteria that are native to your system. It's just they've gotten decompartmentalized, or they are in the correct compartment, but there's just too many of them in that compartment. So that's essentially what SIBO is. Now, the tie in to the thyroid, I think, is fascinating, and I'll just say this very plainly, that there may be a lot of people who think they have a thyroid condition who actually don't. And I'll come to a study in a moment that actually found that 60% 60 of people who had a ambiguous thyroid diagnosis when they were rechecked, 60% of them actually were not hypothyroid. And I think this is because the symptoms of not only small intestinal bacterial overgrowth, but problems in the GI in general can manifest as symptoms that look like hypothyroidism. And just as one example, there was a study looking at patients with ibs, so irritable bowel syndrome, gas bloating, abdominal pain, altered bowel function, and they found a significantly higher incidence of fatigue, depression, and anxiety in that cohort. Now, fatigue and depression are oftentimes attributed to hypothyroidism. So we certainly can see that problems in the gut may manifest as what looks like a thyroid problem. But specifically, there's a couple key points that have been published over the past maybe two years. One, only about six months ago, a study, I believe it was in Russia. It was either in Russia or in Poland. And essentially they found that patients with sibo, small intestinal bacterial overgrowth, had about three times higher the level of TPO antibodies, which are the antibodies that underlie Hashimoto's. Now, I also should be careful in saying that three times sounds like a lot, but this is where.

I don't want to contribute to some of the overzealousness of functional medicine, and I want to be a little bit discerning. So the control group had a level of 39, which is considered just above normal. Usually the cutoff for TPO antibodies to assess thyroid autoimmunity is about 35. So the control group, the non placebo group, had.

I'm sorry. So the control group had a value of 6, and then the SIBO group had a value of either 39 to 94. So it's actually more than the threefold. But here's where the details do matter. While that is a significant elevation of thyroid antibodies in the SIBO group, I wouldn't say it's a huge elevation, because when you look at thyroid antibodies, in my experience, they have to really be over 500, and there's some literature that supports this to really denote a clinically meaningful elevation. So, yes, there is evidence showing that one may have a worsened thyroid autoimmunity situation if they have small intestinal bacterial overgrowth. And that's something you can act on and may help. But I don't want people to think that this is a hugely impactful issue, at least not from the preliminary literature. So it's one thing that can help, but I wouldn't lose sleep over it per se. And the mechanism there may be that when bacteria in the small intestine overgrow, they seem to sequester selenium. And if they're using selenium at the expense of you, the host, we know that selenium does dictate thyroid autoimmunity. So what may be happening? Again, this is more so my speculation than there is any solid evidence to support this. I don't think there's really an answer to this. So I'm just inferring based upon what we do know. But what may happen is that you have someone with a genetic predisposition to thyroid autoimmunity. They develop small intestinal bacterial overgrowth. That small intestinal bacterial overgrowth starts essentially binding to their selenium, making someone a bit selenium insufficient, and then that may exacerbate the thyroid autoimmunity. So that's one mechanism. But here's what I think is the most important data we have regarding thyroid autoimmunity and SIBO. There was one study looking at over 1800 patients, and they were looking to see what were the most associated conditions to small intestinal bacterial overgrowth. So a group of researchers looked at 1809 patients specifically, and they were looking at immunosuppressive drug use, acid lowering, medication use, prior intestinal surgery. And they were expecting one of these to really associate to and increase the risk for sibo. What they found was very surprising. The two most correlated conditions associated with SIBO were being hypothyroid or being on thyroid medication. So there's clearly a high association between SIBO and small intestinal bacterial overgrowth. And then just to finish this thought.

And this ties into something that I've seen in the clinic. Patients come in and they're pursuing what they think is the cause of their symptoms. So they might be depressed, a bit overweight, their cholesterol is a little bit high, and they're fatigued. And they may or may not have digestive symptoms, because you don't always have digestive symptoms that accompany gut inflammation. Sometimes the Gut inflammation is silent and only manifesting and other non intestinal symptoms.

Right, like neurological fatigue or brain fog.

Right, exactly, exactly. So these patients come in and they may be, they may have been on levothyroxine for six months. Then they tried levothyroxine plus cytomel. So you have your T3 plus your T4 plus T3. So it's more of like a custom medication. And they may even have gone and tried Armour or wp, thyroid or whatever. And they never really got the traction that they were looking for. And so what I've been saying now for close to a year is I've been criticizing that in the progressive realms of natural medicine, functional medicine, whatever you want to call it, I think we're doling out hypothyroid diagnoses too quickly and certainly not with near the level of circumspection that we should be using. And when I've gone back and actually checked, I found that some of these patients were never hypothyroid. And you may have been able to nitpick and say, well, their TSH isn't optimal, their T4 isn't optimal. That's a big difference from being hypothyroid. And the clinicians probably in an unintentional way, didn't clearly explain this to the patient, that they were not hypothyroid and yet there may have been a little bit of functional low thyroid status. Nevertheless, they went on a medication and they come to see me five years later. And when I checked their initial lab work, it's clear they were never hypothyroid. They never felt fully improved from the medication, yet they've been on it for five years. This leads me to this most recent study that looked at, and sorry if I'm being a little long winded here, but this is something.

No, this is super interesting.

So this study, they documented exactly what I've been seeing in the clinic. 291 patients who didn't have a firm hypothyroid diagnosis were then tested at baseline, taken off their medication for six to eight weeks and then retested. 60% of those patients were not hypothyroid. That is a huge deal. And the title of the study was essentially Hypothyroid A timely diagnosis, meaning it's a diagnosis now that's in vogue. So it's being handed out more quickly, which it really shouldn't be. And so a couple of things from this study that are important, that the antibodies, nor someone's weight nor their Time on medication dictated whether they had a higher chance of actually being hypothyroid or if they were normal thyroid. So that's just some important context. Ultrasound findings did seem to be somewhat predictive. So that's something that someone may be able to use to kind of sort this out. But said quite simply, if you haven't had definitive diagnosis of hypothyroid and you're on thyroid medication, you may want to speak with your doctor about revisiting this issue to double check if you are hypothyroid or not. And I would say, and I'm not sure how to say this as tactfully as I'd like to, but if your diagnosis was made by someone not in the conventional medicine community, I would be more prone to have it double checked. And I in no way mean that to be disparaging of functional, integrative, or natural medicine. But I do think that there's been some misrepresentation of the data to this community, where some of the clinicians in this space, I think, have been led to believe that hypothyroidism is more common than it actually is. And so, yes, there is this association between SIBO and hypothyroidism in my experience. And it's one of the chief causes of someone who thinks they have a thyroid problem but actually don't, and their symptoms are actually coming from a problem in the gut. And you may be able to get some people off of thyroid medication and fix a problem in their gut and also get them to the point where they're on no thyroid medication and their symptoms are now cleared.

That's super interesting. Now, if somebody wanted to actually test and see if they had sibo, do you have go to test? Because I know that there's been in the past some talk, I think you even mentioned this to me, that many of Acebo tests might not be reliable. Yes.

And I should maybe back up and just say, for people who want to run the thyroid test.

What you want to do is test your TSH and your free T4. And what you're looking for is if your TSH is in the conventional normal range and your T4 is in the conventional normal range, then there's an extremely high likelihood that you are not hypothyroid and you don't need thyroid medication. Now, might there be a minor problem with conversion? Sure. But is the solution to that lifelong administration of thyroid hormone? No. The solution is diet, stress, and I would argue, in large part your gut. So just to give people the parameters there, because this is one of the things that leads to the erroneous diet. Diagnosis of hypothyroidism is using these ranges that are too narrow. And that's a whole other conversation maybe, to get into some of the particulars regarding why some people say that your TSH should be below 2.5, but that's when you're diagnosing the condition.

Yeah, let's focus on SIBO for now.

Yeah, but that is one important thing. Just to give people a note on if they want to run this test of their thyroid status. Now, regarding Sibo, there is some debate on what the best test is, really. I think you have two practical options. Both are breath tests. One uses glucose, the other uses lactulose. You can make a case for either, and I think there's pretty good evidence to make a case either way. The Rome foundation, the largest body in gastroenterology in the world, recommends glucose. The North American expert consensus recommends lactulose. So you have two large, well, credentialed bodies recommending these two different tests. I think as long as you are using the lactulose test, and this is.

Just to clarify, you drink a bunch of lactulose or any of these other sugars that you get sent with the test to your house, then you breathe into this tube, and it tracks how much gas the bacteria produce over a few hours.

Exactly. Well said. Yep. And so there's debate on which test is the best. One of the challenges is the lactulose test may lead to false positives, meaning you may see a positive on your test, but you may not actually have sibo. If you make your interpretive time window from the start of the test to 90 minutes and only look at that window with the lactulose, you seem to safeguard against those false positives. So there's a fairly easy way, at least in my opinion, to get around that. But really, either one can work. Either breath test can work. They're cheap. They're like $200. Even if insurance doesn't cover them, many insurances will cover them. And they can give you some data to move on.

Cool. Now, one of the things that I know, I've seen you recommend for Sibo, and I've tried this diet out, and it's actually. It's pretty good. It's called an elemental diet, and usually it has some kind of a meal replacement powder. I've done it and used Thorne Mediclear and blended it with stevia and ice and actually a little bit of bone Broth and thrown in a little bit of oil in there, a little bit of extra amino acids, and you just drink that for breakfast, lunch and dinner for a while, up to 30 days. I don't know if I just bastardized the elemental diet, but ultimately I'm curious if you can explain the elemental diet and how it would work for something like SIBO or inflammation or IBD or anything else.

Sure. Now, I don't know if that application would actually classify or qualify as an elemental. I think it'd be pretty close and could probably work. The elemental diet is essentially a hypoallergenic. So it's devoid of common allergens and gut healing meal replacement shake. And one of the things that this elemental diet will do is it absorbs in the first couple feet of the small intestine. So the rest of the small intestine and the large intestine all get a break from digestion. And if there are overgrowths, those overgrowths don't have the fuel the food in your diet to help continue to fuel the overgrowth. So it in effect will starve overgrowth. And this is why we see one clinical trial showing quite impressive benefits in small intestinal bacterial overgrowth. A number of trials and ability to decrease autoimmunity and inflammation in the gut in inflammatory bowel disease. Some evidence showing it can help with what's known as eosinic esophagitis or eosinophilic esophagitis, which is essentially an inflammatory condition in the throat. And one study showing benefit with rheumatoid arthritis. So joint inflammation. So it can be very, very helpful. It's not actually as hard to do as it sounds. It sounds like a liquid only diet would be tough. I've done this exclusively for four days as a guy who's 61 and 2, 15 and fairly muscular and eats a lot of food. And I wasn't hungry at all. I actually had great mental clarity and focus.

It can make a lot of these shakes taste pretty good too. Yeah.

Yeah. And I should also mention that.

The older generations of elemental diets tasted kind of like potion stamp glue. They were just, they were horrid. And I say that as someone who can choke down almost anything. And even I was like, gosh, these are terrible. There's a newer generation of elemental formulas that are actually quite palatable, one of which we have released that I'm really proud of. And the feedback that we've gotten from our patients and people who've gone through the book protocol has been Fantastic. Our formula is called Elemental Heal and it's one of these newer generation formulas. And this one thankfully is available without a prescription. That actually tastes pretty good and you won't feel like you want to gag, which is always nice.

Hey, I want to interrupt today's show to tell you about Birdwell Beach Britches. Birdwell Beach Britches, also known as birdies. What they do is they make board shorts. But these are not just any old board shorts. Outside magazine calls them the 501s of the beach and surfers have been wearing these since the 1960s. They actually purpose built built them for all the rigors of surfing, but they're pretty much good for any activity under the sun, visiting the beach, paddle boarding. I mean, I wear them to the gym, rock climbing, wherever. They're made from this unbreakable surf nil fabric, which is super tough. It's Almost an unbreakable 2 ply nylon fabric that was inspired by the sails of boats that were anchored at California's Newport Beach. So these things, should you decide to really put them through the wringer, can survive rock scrapes and reef slashes and, and tons of wear. And they come with a lifetime guarantee. Not only do you get the lifetime guarantee, but they're going to give you 10% off and free shipping for any order over 99 bucks. If you want to grab a few pairs of birdies, you just go to birdwell.com that's b I r d w e l l birdwell.com and use discount code ben at checkout and you can pick up your first pair of birdies and see why they've been an American icon since the 60s. This podcast is also brought to you, something that I highly recommend for this holiday season. They've got red juice for your blood, they've got green juice for detoxification and just a super boost of nutrients. They even have their pumpkin spice evening turmeric gold drink, which this time of year when everybody's craving things like pumpkins and butternut squash and a nice warm mug of relaxation at the end of the day, scratches that itch tremendously and tastes amazing. I like to mix it up with coconut milk. I even put a little CBD in there. You make this amazing nighttime CBD relaxing beverage. I love to cook in the kitchen. Most of my cooking is lazy though, involves a blender and superfoods and organifi makes that very easy. They send all these powders to your house and for all my listeners, you get 20% off of all these organifi superfood powders. So you just go to Organifi organifi with an I organifi.com and you use discount code Greenfield. Discount code greenfield will automatically save you 20% off of your order. Oh, and then finally, one last thing I wanted to throw in there that you've probably heard me talk about. Another superfood company that mixes all these superfoods in with a raw organic honey. Very, very cool delivery mechanism. And I just heard from them yesterday. It's called Gosha's Organics. You've probably heard about these fires in California. Well, what they decided to do was give 20% of every order to all the fire victims in Malibu and also support the Los Angeles Firefighters Department and the Malib Animal shelter. And so the way that they're doing that is you just go to their website goshesorganics.com that's G O S H-A-S organics.com and if you use my discount code, they're automatically going to donate 20% to all the fire victims. So I think that's pretty cool. The discount code is BEN10 percentage sign. This stuff would be an amazing stocking stuffer, actually. Just saying Ben 10 percentage sign gets you 10% off those gauche's Organics. Fine, fine supplements.

I'll link to that in the show notes. If people want to try out this diet, I would recommend you don't just like willy nilly jump into it and try it. It'd probably be better to do the breath test for Sibo, for example, that Dr. Ruscio was talking about. But it's kind of a simple, clean, easy way to, again, like you mentioned, kind of keep the bacteria from having something to feed on. And you had mentioned briefly, Michael, the idea of these African hunter gatherers microbiota and how it might be different than the westernized diet. But there's also, you know, there's people like, you know, Jeff Leach, for example, was made famous. Not made famous, but he, he became a little bit famous for his experiment where he did the fecal microbiota transplant of the stool of a hunter gatherer. He hung himself upside down in the middle of a village, I think it was in Hasda, and just basically replaced his colonic bacteria with that of a hunter gatherer. And then I think he went off and wrote an article on it. I'll see if I can find the story and link to it in the show notes. But what do you think about that? Because you talk a little bit about the microbiota of these African hunter gatherer tribes in the book. And I'm curious what would happen if we were to all do that, like go way back to our roots and just put the bacteria of our ancestors into our current westernized bodies?

Well, it's a great question, and I don't know exactly what would happen if we all did fmts from an African population, like an African hunter gatherer population. But a lot of the mismatch between the research, or I should say, the observational inferences that were being taken from Africa.

And what the actual clinical science says that I kind of opened our conversation with came from this research in Africa. And these cross cultural comparisons are always very challenging because it's really bad science and bad practice to take an entire culture that's different in a vast array of ways and try to excise out from that culture one thing and then replicate that and almost force that item into a totally different population. And so the African hunter gatherer groups that have been studied really provide a compelling example of that, where they eat, in many cases, a fairly high grain diet, a high carb diet, and a diet that's usually about half the calories as many.

Many of us in the West. And they have vastly different immune systems and vastly different lifestyles. Many of these tribes are highly parasitized, meaning they have, almost all of them have worm infections. We're learning that those worms may actually.

Have benefit or even not be parasites. Because secondly, the definition of a parasite is it has to be kind of opportunistic and feed on its host and even do damage to its host. And a lot of these things are just kind of like, as in the west, it's called helminthic therapy. But a lot of people now will use tapeworms and whipworms that are safe to actually affect, for example, a more robust immune system.

Yep. So it's absolutely. And I do think we should be rethinking how we label some helminths or some worms as potentially not truly parasitic. It's incredibly well said.

But all that being said, it does appear that, that the microbiotas of the Africans are adaptations in part to their environment. And when we see similar adaptations in the west, devoid of their environment, they actually might be pathogenic. And methano, Brevarbacter smithii, which I expound upon in the book, provides what I feel to be one of the best examples of this methanol. Brevibacter smithii, is like a cousin to bacteria. It's technically classified as an archaea. And this organism is interesting in the sense that it slows down motility or the movement of food through the intestines, and by doing so helps to extract more calories from the food and helps with more robust breakdown and extraction of calories from food. So, so in an African population that's eating a highly dense, highly fibrous diet and also a lower calorie diet, this is a beneficial adaptation. You slow down the rate at which this food moves through the intestines and you extract more calories from it, so you have more of a chance to extract calories from this dense, hard to break down food to begin with. That works for the Africans. When we see this overgrowth in Westerners, it's accompanied by constipation and it's been fairly highly associated to weight gain, high cholesterol and high blood sugar. So works for the Africans, doesn't really seem to work so well for us. So this is why we have to be careful in trying to replicate the diet of the Africans, because they have this whole environment that's adapted to allow them to thrive on that diet and with that bacterial ecosystem. So we have to be cautious in just replicating that. And this is part of the scientific process. We see those observations and then we formulate hypotheses and then we test those hypotheses. And only after we've tested those hypotheses in clinical trials should we act. Unfortunately, you know.

The translation from what leech is doing to clinical practice isn't often made with caution. And you have people jumping from observation to clinical recommendations. And this is where you can seriously get yourself in trouble. So we should continue to watch this body of evidence and learn what we can from it. But we want to be careful with how closely we replicate our African hunter gatherer contemporaries.

Yeah, so like a carb, high carb, prebiotic, super fiber rich diet works for Africans. But you're a Westerner and you have gut issues. That diet might be the exact opposite of what you need. Like it might feed bacteria, for example, if you have sibo. Or it might feed bacteria that your immune system is attacking or, you know, createcreate more issues.

Exactly, exactly. And the higher carb, you know, obviously if the higher carbon, higher fiber, I think requires a little bit of contextualization, which is if someone's going from the standard American diet to any kind of healthy diet, they are likely going to increase their fiber and prebiotic intake. Just the question is, how far do you go on that spectrum? For some people, a low carb paleo diet may be enough to make them feel totally Fine. If they go to the extreme of going more proximal to a vegetarian diet, which is even higher in carbs and fiber and prebiotic, then they, they may start to have some serious problems with their gut.

Now, one of the other things you talked about in regards to kind of like westernized versus non Westernized societies is how non Westernized societies have less inflammatory and less autoimmune and less allergies because they're living in less sterile environments. So they might have stronger, more robust immune systems. And I thought it was really interesting how you outlined this with a modern day example of Sardinia. Can you explain what the Sardinians did and how this affected their immune system?

Yeah. This is an interesting story that I had heard anecdotal reports about and like many things in the book, I really fact checked them because one of the things I think is not helping the field of integrative medicine, as great as it is, is just parroting these things that we've been told and not fact checking anything. Because if you don't fact check, then you never catch errors and you're never able to get rid of the error and update. So I really did fact check pretty much everything in the book. And you can tell by the referencing in the book, there's just under a thousand references. So I checked into the Sardinian issue because I wanted to make sure this wasn't just some kind of lore from natural medicine. It turns out that this does check out, and I believe it was in the 1950s that Sardinia went through this anti malarial campaign because there was a fairly high incidence of malaria in Sardinia. And what ended up happening years after that was the incidence of multiple sclerosis in Sardinia started to go up to one of the highest in the world. And what the researchers who have been tracking this are now positing is it was a. Or the malaria was a. Or I should say the Sardinian immune system learned to evolve under the pressure of malaria. And it kind of required that little bit of tension in the immune system from the malaria for the Sardinian's immune systems to be optimally healthy. Once that was taken away, the Sardinian immune system that was always kind of used to having this little bit of tension with the malaria. Once that was gone, it's almost to say the Sardinian immune system didn't know what to do with itself. And it was so used to being a little bit turned on to guard against the malaria. Then when the malaria was gone, it was kind of like having a bored army, right? And then the soldiers would get drunk, go into town, start picking fights, and you see this bystander autoimmune effect. And so sometimes things that we don't think are good may actually be good, especially if the immune system has evolved to be in harmony with those. And the same thing applies to the helminths, as you alluded to earlier, where helminths or worms are a fairly common part of the guts in those who are hunter gatherers. And one of the things that may lead or have led to the increased prevalence of autoimmunity in the west is the anti worm campaign that was initiated in the US where now almost no one has worms. But those worms may have actually provided a little bit of background tension against our immune systems to prevent autoimmunity. And now that they're gone, the immune system tips into autoimmunity.

Yeah, I wrote an article about this a couple of months ago. I actually inoculated myself with tapeworms and whipworms just to kind of experiment with how my immune system felt. And ultimately the biggest change I found was far less susceptibility to getting sick. And it seemed to even reduce the symptoms of jet lag when I was traveling all across the globe. So it seemed to kind of modulate the immune system in some way. And I'll link to that article in the show Notes if you guys want to read it. I'll put it over@BenGreenfieldFitness.com HealthyGut but it's a perfect example, this malaria eradication example, of why we may want to keep our immune system slightly challenged. Another thing that I thought kind of reflected kind of a good practical tip was this idea of increasing our bacteria externally, especially like our skin bacteria, and doing so with naturally occurring plant life. So, you know, I've talked about the NASA Clean Air study before and how my wife and I have placed houseplants around the house that naturally clean the air based on many of the plants, like English Ivy and peace Lily, that they identified in the NASA Clean Air study. But then you kind of take this to the next level as far as plant life. Can you explain what's going on when we, when we have plants in our home or surround ourselves with plants?

Well, I talk about a couple of studies in the book that were interesting most. Namely, there was one cohort study that looked at children growing up in environments where there was a high diversity of naturally occurring plant life around the home compared to children in environments where there was a low diversity or just a low amount of naturally occurring plant life around the home. And what they found was very interesting. The diversity of plant life correlated with the diversity of bacteria on the skin of these children, which was inversely related to inflammation in the skin. So the higher the plant life, the higher the bacterial diversity on the skin, the lower the inflammation in the skin. And that led to a lower amount of things like atopic dermatitis or just skin allergy of various sorts of. So there does seem to be some kind of benefit from having a diversity of plant life around your home. Whether we can replicate this by buying plants and putting them in the home, I don't know that that's been shown. But I wouldn't think that would harm in any way and certainly could only be neutral to, hopefully beneficial.

Yeah, it was a really interesting takeaway. And then you kind of get into the realm of probiotics, and this is a big one for a lot of people, especially in light of that new research I talked about earlier that found that I think the primary takeaways are large intestine bacteria don't necessarily reflect what's going on in the small intestine, even though all these microbiome tests are testing the large intestine, the stool. And then I think the other takeaway was that many of these probiotics, even though they seem to have some kind of an effect on things like IBS and IBD and depression, and many of the things that probiotics have been studied to be somewhat efficacious for, they don't appear to actually kind of seed or populate the gut. So there's a lot of confusion out there regarding probiotics. And you have some really good sections in the book on probiotics, but what's your take on them? I mean, do you use them? Do you prescribe them? Do you think they even work? Do they stay in the gut? I mean, what's going on with probiotics in that respect?

Well, you're right. And one of the, I think most, I guess, counterintuitive things that is important to mention regarding probiotics is that most probiotics, with the exception of a few, do not colonize you. And this kind of throws a monkey wrench in the previous philosophy of, well, you need to, like you said, reseed the gut and repopulate with healthy bacteria. And that doesn't really seem to be the way this plays out. I think a better way to think about probiotics is you have this bacterial colony in your gut. And with stress, with poor diet, with environmental insults, with the fact that we grow up in an environment that's fairly sterile. And if you were not breastfed or if you were caesarean birthed, you know, all these things are negative knocks against that bacterial community in your gut. What I think probiotics can do is they can provide a nudge to the microbiota that can help reset it to a healthier equilibrium. And if we pair that nudge with the appropriate diet and lifestyle inputs into the gut, then we can help that nudge to maintain this eubiosis or this balance in the longer term. So healthy diet and lifestyle foundation paired with a nudge from probiotics seems to be able to help reset the microbiota to a healthier equilibrium. And so I should mention that one of the things that probiotics do that I think is underappreciated is they're actually antibacterial, antifungal and antiparasitic, perhaps using the term parasitic loosely. But they do seem probiotics, that is, to be able to combat things like small intestinal bacterial overgrowth and candida. So a properly used probiotic can have a lot of benefit for reducing overgrowths and also helping to reduce inflammation, repair leaky gut, and help with a number of symptoms. But it's not to say that they will repopulate your gut with this missing bacteria, but rather, again, if you have these imbalances, because the probiotics can help to kind of dislodge some of these imbalances and reset you to a healthier equilibrium.

Now, what about when to take them? Because you mentioned the use of probiotics in kids. My kids eat a wide variety of fermented foods around the house, like kimchi and coconut yogurt and sauerkraut and miso and things like this. But they don't take a probiotic per se. I think they have like, like some of the smarty pants probiotics upstairs and they have access to my probiotics. But do you think it's beneficial for kids to be using probiotics?

Well, there have been a number of studies showing that probiotics can be helpful for children. And one of the first things I wanted to look at was how early can we go with probiotics? Is there some sort of time we need to wait before we give a probiotic? And could a probiotic perhaps given to an infant be detrimental in some way? And even if you look at children in the NICU or preterm infants, there is a benefit derived from taking probiotics. In fact, one study found that administration of probiotics before 27 days of life decreased the incidence of type 1 diabetes. And if the probiotics were administered after 27 days of life, there was no impact on type 1 diabetes, which is an autoimmune condition. So that's just one study. But there does seem to be this trend. And to state it simply, the earlier an antibiotic is used, the more detrimental it is. And the earlier a probiotic is used, potentially the more helpful it is. Now, probiotic foods, you know, how do they interface in here? It's hard to say. I would assume that probiotic foods or supplemental probiotics would have a similar impact. I don't know that we have great research yet looking at fermented foods in infants and toddlers. We do have those studies with probiotics and we do see benefit. I would assume the same thing would happen with a probiotic. So I would say for a child you can use either.

If you're pre food, then obviously a probiotic would be the way to get there, or at least a mother taking it. So hopefully she gets some crossover benefit into the child. And then as, as they're growing up, I would say use either fermented foods or probiotics or a little bit of both.

Yeah, I mean really, probiotics would be almost more targeted delivery though, because, you know, when you look at live microorganisms, assume you're not eating like a, like a heat pasteurized probiotic, like a lot of these store bought sauerkrauts, for example, are.

The thing is, they might not be necessarily reliable as a source of beneficial, effective bacteria if you're trying to target your body with a specific strain of bacteria. But if you want just kind of that shotgun approach of a wide diversity of bacteria in your system, I think that regular use of those and then targeted use of probiotics seem to be somewhat effective. And in terms of targeted use of probiotics, there is this concept of like survivability and whether a probiotic can actually survive the acidic journey through the digestive system and make it, for example, through the colon. And you know, I've seen some folks now talking about like newer probiotic strains that might actually seed the gut. That's even the name of one of them that people are talking about is this company called Seed that's making probiotics that they say actually survive the acidic environment in the gut and populate the gut. Have you looked into strains like that at all that have enhanced survivability?

You know, I've looked to some extent into these enteric coated Probiotics. And my thinking here is the consumer needs to be very careful with the claims regarding probiotics. I remain very open, but I think there's much more hyperbole than there is here actually actionable or helpful advice. And I think what you're going to see, because probiotics are a market that many companies want to get into, you're going to see progressively more outlandish claims made to market a product, because the more people are marketing, the more marketing claims are made. Now you have to market even harder. You need newer, more novel pathways and mechanisms to market. So I can tell people that with the simple three category probiotic system that I use, with the three probiotics that I recommend in the book, which are good, clean probiotics that have the appropriate ingredients and the appropriate dosing. But with those, we have been able to take people who have positive Candida and Sibo in their labs and the only thing they've needed to do is to use a probiotic protocol. And this does make a difference. I remember most succinctly or distinctly with Rob Wolf. Wolf, he had done all types of gut protocols, obviously, because Rob Wolf knows everybody. And he finally pulled me aside and said, hey, do you have anything I should try? So I gave him this probiotic protocol and there was two categories of probiotics in my three category system that he hadn't tried. And that was a huge game changer for Rob, not using the newest novel probiotic, which he was doing, I think, for a while, and getting the bells and whistles and just understanding that it's important to present the gut with this diverse array of probiotics using all three of the categories. And that was able to make a substantial impact. I'd be cautious because this is something that you're going to see more and more of. I watch the literature and if there is something significant there that needs to be acted on, I'll be one of the first people to adopt. But I am highly suspicious that the consumer is going to be just bombarded with all these different claims.

Yeah, I think with that seed company, they're using some kind of like a. They're using algae as a delivery mechanism and I think they're somehow coating the bacteria with algae and they say that it survives transit through digestion. But I don't know, I was just curious if you'd used anything like that. But the other thing that you talk about is also this deal with using E. Coli as a probiotic. And that surprised me because a lot of people think E. Coli is just found in bad hamburgers and is going to make you sick. Sick. But you actually talk about E. Coli as therapy, as gut therapy. Where does E. Coli fit in when it comes to probiotic supplementation?

Yeah, great, great question. And very interesting because there are pathogenic E. Colis like enterohemorrhagic E. Coli, but also a fairly prevalent member of your healthy commensal bacteria are different types of E. Coli. And so I mentioned earlier the three category system of probiotics. Well, there technically is a fourth, which I mentioned in the book, but for most conversations like this, I don't discuss the 4th because the 4th isn't really available in the US for weird regulatory reasons that I don't quite understand. While these probiotics are available in Europe and many other countries, they're for some reason not available in the U.S. even though there have been a number of clinical trials showing benefit, there's one that trade names as Mutaflor, which is E. Coli NISL 1917 and it's a strain of E. Coli and it's been shown to have quite impressive benefit like the other probiotics. I think all good probiotics of category one through three or this category four can be highly beneficial. So for someone who hasn't tried an E. Coli probiotic, it's something to consider. And yes, there are healthy strains of E. Coli that can be beneficial. And there have been a number of trials, mostly in inflammatory bowel disease, showing benefit with some of these E. Coli based probiotics.

Hmm, interesting. And you can actually look on the label and you can actually find E. Coli as an ingredient on the label.

Yeah. Yup.

Interesting. And so when people get a gut test and it says that they have E. Coli, those could actually be beneficial strength strains of E. Coli.

Oftentimes that's what you see. And.

It'S helpful to understand that E. Coli is a natural resident of the gut. And so unless it's identified as a pathogenic E. Coli, many times this just tells you that you have just like Lactobacillus or Bifidobacterium, you have E. Coli growth in your gut, which isn't a bad thing.

Now you also say in the book that we would be surprised about what, what you found in your research for the book about dietary fiber. You'd be surprised about dietary fiber. What is it that people would be surprised about when it comes to dietary fiber?

Well, I guess to say it concisely, the benefit of dietary fiber I think has been vastly overstated. But we have to Paint one, I think important background nuance, which is a low fiber diet that's high in sugar, high in trans fat, and high in processed foods is not healthy. But when you leave that SAD diet, which I'm sure no one listening to this has done probably in a long time, when you leave the standard American diet and go to pretty much any healthy diet, from low carb all the way through a healthy vegetarian diet, you're probably okay in terms of your fiber intake. And there's a fairly large swing in terms of the fiber intake from a low carb diet all the way through a vegetarian diet. But it doesn't really seem to matter. This was the most difficult part of the book to write because I was presented with 167 pages of abstract summaries on the research regarding fiber. This was the point of the book where I literally almost gave up. There was so much data and having to try to parse through the data and essentially say, okay, here's 167, seven studies. We have to weight these by importance, and we have to also divide these by studies that show fiber has a health impact compared to fiber has no health impact. And that was quite difficult. But after going through that daunting process, the conclusion that emerges is fairly clear, which is there has been no consistent benefit shown from a higher dietary fiber intake and even some studies using diets that are relatively lower in fiber to some of the studies that they've been compared against and showing actual benefit. For example, one study looking at a paleo diet next to a Mediterranean diet in the prevention of colorectal adenomas showed similar ability to prevent occurrence of those.

Now, when you're saying high fiber versus low fiber, what are we talking here in terms of the number of grams of fiber?

Well, that's the actual convenient thing, which is it doesn't seem that we have to be highly prescriptive with this recommendation because it does get complicated. You have soluble fiber compared to insoluble fiber. You have fiber from fruits, you have fiber from grains, you have fiber from vegetables. So it's been looked at in all different ways. But the trend that emerges, and if people want the deeper dive, they can read the book to kind of go through this on a study by study level. But the trend that you see is that higher fiber intake. There are some studies showing benefit from higher fiber intake, which is what a fiber enthusiast will cherry pick and cite when they're trying to support the argument that you must eat a lot of fiber. But they will leave out the other evidence. Showing that higher fiber. And this will vary in terms of how much fiber and the type of fiber. But. But numerous studies also show no benefit from a higher fiber diet.

So that's important to factor in. And then also when we look at studies that compare something like a vegetarian diet to a paleo diet or a pritikin type diet compared to maybe a low carb type diet, you actually see equivalent results. And even specifically for metabolic conditions, a slight favoring for benefits in metabolism from a moderate to lower fiber intake. So there's not the specific gram that one needs to shoot for to say that they're high fiber, moderate fiber or lower fiber, but rather I would say whatever diet you feel best on, anywhere from low carb, which tends to be a little bit lower in fiber, all the way through high carb, which tends to be a little bit higher in fiber. Feel okay about that because there's no consistent evidence showing that you need to be eating higher fiber to have a healthier colon or just be healthier overall.

You hear that a lot from people now who are following the carnivore diet. You know, eating a lot of meat, and granted meat has a little bit of fiber in it, but they're not eating a lot of fiber yet seeing in some cases reversal of a lot of gut issues and inflammation and ibd. Have you looked into the carnivore diet at all or thought about that when it comes to fiber?

You know, I've had some patients who have fooled around with it, Some have done very poorly on it, and some have done really well on it. And my thinking is that the carnivore diet is almost like an extreme elimination diet, because we know that plant foods contain a number of things that can be noxious. Lectins, saponins, oxalates, some sulfur fiber, fodmaps, and even just fiber in and of itself, especially vegetable fiber and insoluble fiber can all be irritants to the gut. And so what I think is happening is in part this is just like taking everything or not everything, but many things that could be problematic to the gut and just wiping them all off the table in one fell swoop when you go on the carnivore diet. So I like it from. I don't know if I would say I like it, but I see the plausibility of it it as an initial elimination diet and then one should heal after a while on that and then try to move to the broadest diet possible.

I have the same opinion, by the way. I don't think that it has anything magical to do with eating a copious amount of meat every day. I think it's the fact that you just simplify the diet to the extent where you just aren't eating barely anything that could cause gut inflammation. But at the same time.

This might offend some people, but I think it's almost like a lazy diet, kind of similar to the elemental diet. Right. It's like I'm just going to eat the same thing for breakfast, lunch and dinner and screw food, food prep, cooking, learning more about the wonderful world around me. Eating a whole foods diet, like kind of a Wesley Price ish diet, where you're actually learning and building a relationship with food versus just like throw another slab of meat on the grill for breakfast, lunch and dinner. I just think it's almost like a little bit of a myopic, overly restrictive diet that's kind of like a lazy way out, but that ultimately if you eat that way your entire life, I suspect you get pretty bored. Most people I've talked to about it, they're like, yeah, I love ribeye, but after a month or two they're just.

Like, I'm getting kind of tired. And I agree. And I would be prone to think that this diet would show some type of deleterious impact in the long term. Just like we in the kind of paleoish camp or one in the paleoish camp loves to criticize the vegetarian diet for the potential for nutrient deficiencies. I think the same logic applies here that a diet that's too extreme in what it limits opens the door and increases the likelihood of some type of nutrient deficiency in the long term.

Yeah. I wanted to ask you one other question and this was just like a little anecdote from your book that I found very interesting. And it was this idea of melatonin actually being something that could help with a leaky gut. And I'm curious if that is literally like just supplementing with melatonin or if it is more related to sleeping more or sleeping better or what's the deal with melatonin?

Well, I would definitely say that the optimum choice would be to have your sleep be adequate and quality to try to goose the melatonin pathway for gut health. But there has been at least one trial showing an ability to improve IBS symptoms with supplemental melatonin. And melatonin does seem to have an anti leaky gut mechanism to it, perhaps due to its antioxidant capacity. So I mean, it's certainly something that you could tinker with. It's not something that I use for that application in the clinic. If someone's having a hard time sleeping, then I think melatonin is definitely a supplement to consider because it has secondary health benefits.

So I see it having applicability there. But if someone's having a hard time sleeping, I would say look into the health of your gut because it has been fairly well identified that inflammation in the gut can lead to insomnia. So there's kind of this closed loop circle where problems in the gut may lead to insomnia, that insomnia may decrease melatonin, that melatonin may make their gut worse and they're stuck in this self feeding cycle. So yes, melatonin can help with leaky gut.

Did they say any of those studies? Do you remember how much melatonin was being used?

I don't. I'm assuming it's probably anywhere from 5 milligrams a day to 10. Melatonin probably somewhat standard dose. A little bit on the higher side there, but it's not something I would say use a probiotic way before you use melatonin for healing leaky gut.

Interesting. I just thought that was kind of a cool anecdote was the use of melatonin. So I'll link to some of the research on this and also everything that we talk about if you just go to BenGreenfieldFitness.com HealthyGut that's BenGreenfieldFitness.com healthy gut we kind of only scratched the surface in terms of the actual book, but I consider this to kind of be, you know, to a certain extent almost like a cookbook for if you have like gas constipation, bloating, sibo, you've noted something on your gut test results that you want to take a deeper dive into. The book is a really good resource, almost like a coffee table resource for your gut. And Dr. Ruscio also has a podcast that's really good, that has a lot of of really good research based science on the gut, which is what I really appreciate about Michael is he actually has research to back everything up. Like there's over a thousand different studies just referenced in this book alone. And he also puts out a newsletter that's pretty good when it comes to kind of keeping your gut dialed in and getting access to the latest research on the gut. So the book is Healthy Gut, Healthy youy. I'll link to it and everything we talk about over@BenGreenfieldFitness.com.

And Michael, thanks for, thanks for coming on for a three peat on the podcast.

Yeah, thanks for having me. Been a lot of fun.

Awesome folks. Well, I'm Ben Greenfield along with Dr. Michael Ruscio signing out from BenGreenfieldFitness.com have an amazing week.

Want more?

Go to BenGreenfieldFitness.com where you can subscribe to my information packed and entertaining newsletter and click the link up on the right hand side of that webpage that says Ben Recommends, where you'll see a full list of everything I've ever recommended to enhance your body and your brain. Finally, to get your hands on all of the unique supplement formulations that I personally develop, you can visit the website of my company kion@getkion.com that's getkion.com col.