Ep. 276 Nurturing the Gut Microbiome: Impact of a Long-Term Gut Health

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Today, I have the honor of connecting with Dr. Robynne Chutkan, one of the most recognizable gastroenterologists in the United States. She is also the author of Anti-Viral Gut, one of the books I enjoyed reading most in 2022!

Knowledge of the microbiome dates back to the 1600s when Anthony van Leeuwenhoek observed bacteria in his dental plaque through a microscope. However, it has taken us several centuries to understand the interdependence and beneficial nature of those bacteria. The terms “microbiome” and “microbiota” are often used interchangeably. They refer to the organisms and genes that live in and on our bodies, predominantly in the GI tract. Those organisms include bacteria, viruses, protozoa, fungi, parasites, and archaea, which, despite their microscopic size, collectively weigh around four to five pounds. 

Today, Dr. Chutkan and I dive deep into the physiology of the microbiome and discuss how that interplays with immunology. We discuss the benefits of hydrochloric acid, the impact of proton pump inhibitors and other medications on the health of the gut microbiome, and the role of dysbiosis and the Estrobolome. We get into how the pharmaceutical industry has influenced both medical practice and the outlook of healthcare providers, and we talk about the impact of sleep, exercise, stress, and alcohol on the gut. Dr. Chutkan also shares top tips from her anti-viral diet book on the best ways to support the gut. (One of her tips is to consume 30 plant types per week for a healthier gut microbiome.) 

This show has been one of my favorite podcasts I have recorded in the last year. I hope you enjoy listening to it!

“It turns out that 70 to 80% of the immune system is actually physically located in our gut.”

– Dr. Robynne Chutkan


  • What is the microbiome, and why is it important?
  • Why do we need to understand the interrelationship between the oral microbiome, the gut microbiome, and the vaginal microbiome?
  • The importance of stomach acid.
  • How do proton pump inhibitors affect gut health?
  • The three big things that interfere with digestion.
  • How pharmaceutical companies have taken over medical education.
  • The role of statins in women.
  • The importance of the Estrobolome test.
  • The three different types of estrogens in the body.
  • Why exercise is an important contributor to gut health.
  • The net impact of low-quality sleep on immune function.
  • Dr. Chutkan shares her top tips for a healthy gut microbiome

Connect with Cynthia Thurlow

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Check out Cynthia’s website

Connect with Dr. Robynne Chutkan 

On her website 

On Instagram (@gutbliss)

Books by Dr. Robynne Chutkan:

The Anti-Viral Gut: Tackling Pathogens from the Inside Out

Gutbliss: A 10-Day Plan to Ban Bloat, Flush Toxins, and Dump Your Digestive Baggage

The Bloat Cure: 101 Natural Solutions for Real and Lasting Relief

The Microbiome Solution: A Radical New Way to Heal Your Body from the Inside Out

Books mentioned:

Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker


Cynthia Thurlow: Welcome to Everyday Wellness podcast. I’m your host Nurse Practitioner Cynthia Thurlow. This podcast is designed to educate, empower, and inspire you to achieve your health and wellness goals. My goal and intent, is to provide you with the best content and conversations from leaders in the health and wellness industry each week and impact over a million lives.


Today, I had the honor of connecting with Dr. Robynne Chutkan. She is one of the most recognizable gastroenterologists working in the United States and she is the recent author of one of my favorite books I read in 2022, The Anti-Viral Gut. Today, we dove deep into the microbiome in terms of physiology, a bit about immunology and the interplay between both, benefits of hydrochloric acid, the impact of proton pump inhibitors and other medications on the health of the gut microbiome, the role of dysbiosis as well as the estrobolome, the influence of the pharmaceutical industry and how it has impacted medical practicing and our outlook as providers, the impact of sleep, exercise, and stress on the gut as well as the net impact of alcohol, and her top tips in The Anti-Viral Gut book in terms of how best to support our guts, and one top tip was that we need to be consuming 30 plant types per week for healthier gut microbiomes. This has been one of my favorite podcasts I’ve recorded in the past year. I hope you will enjoy this conversation as much as I did recording it.


Good morning, Dr. Chutkan, I’ve been so looking forward to this conversation.


Robynne Chutkan: Oh, I’m so thrilled to be here. Thank you so much for having me.


Cynthia Thurlow: Well, I’ve been able to again read your book for the second time, your most recent book, and I would love to really start the conversation discussing the physiology of the microbiome. This is something that I didn’t learn a lot about when I was back in my medical training days, but it has kind of evolved over the last 20 years, and I’m sure it has greatly influenced the work that you do. And thank you for the wonderful work that you do in the books that you do. I think you bring such a fresh perspective, one that’s really accessible. Let’s talk about the importance of the gut microbiome and what it is, how it impacts, how we interact with our environment. And certainly, over the past three years, I think for many people, they probably have started to look a little bit more closely at how it impacts immune function and our health in general.


Robynne Chutkan: The first thing I’ll tell you is that when I was in medical school and I graduated from medical school 30 years ago, so when I was there 34 years ago, we’re all busy trying to figure out how to be as clean as possible. And I’m sure you remember that too. In nursing school, we’re busy, let’s sterilize everything and make sure there’s not one germ anywhere. And while that’s certainly appropriate for certain settings, like the operating room, for example, you want that to be as sterile as possible. It turns out that not only is that not important for our everyday life, it’s a terrible idea.


So, we’ve actually known about the microbiome since 1600s when Antonie van Leeuwenhoek first looked at his own dental plaque under the microscope and I think was pretty aghast and was like, “Oh, my goodness.” I think the actual term in the ancient medical journals is he saw little animalcules so prettily moving and he was looking at bacteria. But it has literally, Cynthia, taken us a few hundred years to figure out that these organisms are really very much interdependent, and they’re primarily here to help us. So, we’ll start just with a definition for some of your listeners who may be less familiar. I know you have a very sophisticated audience, but for those who are less familiar with what we’re talking about, first of all, we generally use the term microbiome and microbiota fairly interchangeably. One is referring to the organisms, other is the organisms and their genes. But for the purposes of everyday discussion, I think it’s fine to just say microbiome.


So, we’re talking about all the organisms that live in and on our bodies, mostly in our GI tract. And we can’t see them. Obviously, they’re microscopic. We’re talking about bacteria, viruses, protozoa, which are little one-cell organisms, fungal organisms. Those are important for our health too, parasites, all of these archaea, and if we scrape them all up, would weigh about four to five pounds, even though they’re microscopic. And to put it in perspective a little bit, like, how many microbes are we talking about? If we take a drop of fluid from our colonic secretions, they’re about a billion microbes in that one drop. So, a lot of organisms and I always like to point this out in medical school, there’s all this hierarchy, like the neurosurgeons and the neurologists think the brain is most important organ, the cardiologists think it’s the heart, the nephrologist thinks it’s the kidneys, and of course, as a proud gastroenterologist, I have to say, of course, it’s the gut. Look at where the gut is located. It is in the smack-dab center of our bodies and it is an engine for our entire body. So, to sort of comment a little bit on the great point you were making, that the gut, the microbiome is having a moment in the last 20 years, we have realized that the gut is a central organ with spokes going in all these different directions. The gut-brain connection, the gut-heart connection, the gut-kidney connection, the gut-bone connection, it is intimately linked to all of these organs. And to know more organs, is it more closely linked than to the immune system, the gut immune connection because the immune system is literally right there on the other side of the gut lining?


When you were in nursing school, when they talked about the immune system, I had no idea physically what they were talking about. I mean, did that make sense to you if you think back?


Cynthia Thurlow: No. Not at all. And in fact, I would say if you were to pick a body system that I know the least about, I would say immunology without question because it seems so intangible. Whereas the stomach I can touch and see, hopefully not touch, I can see, I can envision what it looks like, a heart, a brain. The immune system to me was that’s very abstract. It didn’t really make a great deal of sense other than I was at Hopkins at a time when it was the HIV AIDS crisis. And so, looking at immunity from that perspective, people that were immune compromised, I understood that. But beyond that, no, it seems very abstract.


Robynne Chutkan: And to circle back to the AIDS epidemic, I was in medical school in really the early 90s, and during my residency and now AIDS HIV has become sort of this chronic disease, almost like diabetes, but people were dropping dead left and right. I mean it was a crazy time. Young people, sure you remember, were coming into the hospital and were literally dying because a lack of a functioning immune system. So, I actually think that immunologists were sort of faking it a little bit back then. I don’t think necessarily really you, [Cynthia laughs] but it was this ephemeral thing like these cytokines and cells floating around, but where exactly are they?


And so, it turns out that 70% to 80% of the immune system is actually physically located in our gut and it is right on the other side of the gut lining. I think sometimes the most incredible things in medicine are the simplest. So, this is the other thing about the gut that I was a practicing gastroenterologist for probably 20 years before this really occurred to me, that when something is in your gut, it’s outside your body. It is not in your body. It’s in this hollow 30-foot-long digestive superhighway that travels all throughout your body. In order to get into your body, it has to get absorbed through the gut lining, get into the bloodstream, get carried to a distant organ, etc.


So, the gut is actually this hollow conduit that is in contact with the environment and that is outside our body. And what is inside our body is the immune system. So, on the other side of that gut lining, the epithelial barrier, are all these immune processes that are happening and there’s constant communication. Like those microbes are literally signaling, literally sometimes kicking the wall of the gut to say, “Hey you guys, mountain immune response.”


So, once you sort of understand that physical location that 70% to 80% of the immune system is– a lot of it in the small intestine along that gut border and that they’re constantly communicating with our gut microbes. Then you start to see, “Okay, the gut lining is really important and the microbes are really important and the gut immune connection is really important.” So, it took me a really long time too.


Cynthia Thurlow: I think for many of us, if you really reflect on that, they probably just assume it’s just a tube that communicates across your entire body and just understanding that there are protective mechanisms in this alimentary canal that many of us take for granted. Much to the point when I was working in cardiology, I think many of my patients ate food. They didn’t think about their food after that and they didn’t think about the net impact on their digestive system, their cardiovascular system, their entire body systems unless they started having pain or discomfort or something wasn’t moving properly. Then they would consider, “Oh, maybe it’s something I’m eating that is driving some of these symptoms that I’m experiencing.”


Now you alluded to the fact that we have beneficial and nonbeneficial microorganisms in the gut and everything in the body is really looking for a sense of balance. It’s not all one good, it’s not all bad. And so, understanding that our modern-day lifestyles in many ways can impact this very delicate balance between symbiotic and nonbeneficial bacteria. And I know we’re going to talk about dysbiosis, which is one of those things I haven’t been able to talk about on a podcast yet, so I’m really excited about that.


But talk about the way that we have this interaction between our digestive system and our immunologic function and how there’s this crosstalk in terms of if we’re exposed to a pathogen, something that doesn’t belong, how does our body react to what does not belong? There’s both a fast-acting immune response and then one that is a little more sophisticated and takes a bit longer to kick in.


Robynne Chutkan: Sure. So, there is your innate immune system that you’re born with that responds fairly quickly, but nonspecifically. So, if you get a cut, for example, it will release white blood cells to sort of try and heal the injury. And then there is the adaptive immune system that is learned. So, for example, every single pathogen that we’re exposed to our immune system keeps track and then will create a memory so that when we’re exposed to it later on, we can react to it.


This is a basis for a vaccine. As you know, Cynthia, when you get a vaccine, you get a small amount of the substance so that your body’s immune system is able to create some memory cells. And then when you see it again, you now have protection. You have antibodies, etc., to it. And so, you are immune. There are some diseases, some pathogens where we don’t need a vaccine because we have natural immunity once we’re exposed to it, our body is able to fight it again and we’re immune.


So, the adaptive immune system takes longer, it’s slower, but it can mount a more specific immune response. That’s typically a more robust immune response. But here’s the thing and I always like to say if I’m giving a talk in person, I’ll say all the good people in the room raise your left hand and all the bad people in the room raise your right hand. And most of us have both hands up. We can be sometimes good and sometimes bad. We have a little bit of that in us.


Well, when we think about what we’re going to get into in a little bit, this idea of dysbiosis and the microbiome, it’s all about balance. There are some organisms that are clearly pathogenic Ebola, bad actor, there’s no good Ebola. But for most of what we’re talking about, it’s a matter of over or underrepresentation. Things get out of balance. And I liken it to a high school classroom. My daughter’s a senior, graduating in a few weeks. And you want that diversity. You want some nerds, some athletes, some quiet ones, some loud ones, maybe there’s even a bully or two in there, but it’s the diversity of the classroom that creates the richness of the experience.


Now, if you have too many bullies or too many nerds, or too many athletes, then things are a little bit imbalanced. But it’s actually that you wouldn’t want a classroom full of good students of the super nerdy ones, you want a mix. And the same is true in society. You need that balance and that diversity. And so, what happens typically with dysbiosis is a lot of the healthy foundational species get killed off, too many antibiotics, acid-blocking drugs, or super sanitized environment. We’ll get into all the causes in a little bit, but you have a reduction of the healthy sort of foundational species and then you start to get overproduction and colonization with some of the species that are normally there.


But now they’re overrepresented and then pretty soon you get colonization and the place is sort of overrun with the athletes or the nerds or the bullies or whoever it is. And a yeast infection is a great example of that. We know that when we get a yeast infection, it’s not really an infection. The yeast, the candida is there normally in our vaginas. But when we take/want too many antibiotics, we kill off the healthy lactobacillus species that are the predominant species in the vagina. And now the candida species are like “Woohoo, we got extra room, let’s go out and multiply.” And lo and behold, you have yeast overgrowth.


Now if you approach that by just saying, “I’m going to get me some nice statin and I’m going to kill off all this yucky candida.” You will suppress the candida, but you’ll still have all this extra room that was created by the lack of lactobacilli. And unless you really focus on regrowth and repopulation with a healthy lactobacillus, you’re going to end up with recurrent yeast infections. And the same is true for bacterial vaginosis.


My OB-GYN colleagues find me really annoying. They’re like, why don’t you stick to the gut? Why are you trying to be a vagina doctor? But I’m really not trying to be a vagina doctor. But when we think about the vaginal microbiome, we have to apply the same principles that we use to the microbiome as a whole, which is balance. And so, what I see with my OB-GYN colleagues is a woman will come in with bacterial vaginosis, BV, the commonest indication for a woman to see her OB-GYN actually.


So, she will come in with typically, unlike a yeasty problem, where there’s typically that thick, white, sort of cheesy looking discharge, it will be a thin, sometimes smells like fish, odor discharge, and sometimes there’s itching. And she’ll be diagnosed with BV, bacterial vaginosis, and she will be given an antibiotic.


So, the antibiotic, what’s happening with BV is that instead of overgrowth of yeast, you have overgrowth of some of the species that are normally in the vagina, Prevotella, Gardnerella, but they’re overrepresented. So, the ratio of lactobacillus to these other guys is off. And so, the Flagyl, the metronidazole that she’s given will reduce the Prevotella, Gardnerella, but it will also reduce the lactobacillus.


So, everything will be fresh as a garden for a minute and then as soon as things start to come back, you’ll come back again with the same imbalance BV. So, the key is to focus on repopulation with the missing species. And of course, that doesn’t mean vaginal probiotics more than it means gut probiotics. It means judicious use of the antibiotic that killed them off in the first place. So, it’s one of the things that I see over and over again, and I see women coming in on their fifth course of Metrogyl or whatever it is that I’m like, “This clearly isn’t working.” And it’s the same thing I see with bacterial overgrowth in the gut. I see people coming in, taking these strong antibiotics, feeling better for a few weeks, and then it recurs because they’re really not paying attention to what we’re missing and sort of taking this scorched earth approach where we’re just going to kill all the bacteria and hope for the best.


Cynthia Thurlow: Yeah, and I think it’s important for people to understand this interrelationship between the oral microbiome, the gut microbiome, the vaginal microbiome. It’s not as if they are closed-off entities, they are all interrelated, one begets the other. And much to your point, I can imagine as a gastroenterologist in terms of proximity, that would be a concern if someone’s having recurrent vaginal imbalances that are creating symptoms and the antibiotics or therapies that are being used, they impact the complaints and the symptoms on an acute level. But on a chronic level, they’re not addressing the root cause, core issue that is creating the imbalance or sustaining the imbalance that’s perpetuating the symptoms.


Robynne Chutkan: That’s exactly right. That’s exactly what’s happening.


Cynthia Thurlow: [laughs] Now, I think it’s helpful to kind of another aspect of the gut microbiome and looking at the digestive system, things that we take for granted that are very important. I’m thinking about hydrochloric acid. We learn about it in biology. We go on to learn it at a deeper level and anatomy and physiology at an undergraduate or graduate level. Talk about hydrochloric acid and I’m hopeful that we can kind of bridge the understanding of hydrochloric acid and a certain medication or class of medications called proton pump inhibitors, which I was guilty of prescribing. Every single patient that came to the hospital got put on Protonix in cardiology. And they’re designed to be short-term drugs. And what’s happening is they are now being used judiciously for a very long period of time. And so, we have a whole generation of individuals that don’t even recognize the net impact of not having enough hydrochloric acid, what that does in the body, and why that’s so significant.


Robynne Chutkan: It’s such an important topic, Cynthia. And I’ll tell you, in the summer of 2020, there was a large population-based study that was published in one of RGI’s journals. It was 53,000 people. And they asked a simple question, “Does being on a proton pump inhibitor increase your risk of COVID?”


Now, for me, as an integrative gastroenterologist, I knew the answer was yes because we know that when we block stomach acid. And these drugs, let me tell you, they are superb at what they do. They are A+ in terms of performance because they shut down that proton potassium ATPs that proton pump in the stomach. So, they create a medical condition called achlorhydria. Achlorhydria is a medical condition where you don’t have stomach acid. And it’s a pathological condition. And that’s the state that these drugs are putting us into. So, the question asked, “Does not having stomach acid increase your risk of COVID?” And the reason I knew that was a yes is because we have seen for decades that people on these drugs, proton pump inhibitors, have higher risks of foodborne illnesses like salmonella, shigella, certain types of E coli, of Clostridium difficile.


So, any of these enteric infections, infections that affect the gut and SARS-CoV-2, of course, gets into our body through the gut a lot of the time, also through the lungs. So, any of these infections that enter through the gut, if you don’t have stomach acid, you are much more susceptible. Why? Because stomach acid literally kills these pathogens. In the case of SARS-CoV-2, it unravels that viral protein, the spike proteins, and it dismantles all of that and makes it much less able to bind to those ACE2 receptors which are throughout the gut.


And so, when you don’t have stomach acid, you’ve lost your body’s main defense mechanism. Like, probably your most important defense, which is for stomach acid to denature the viral protein and render the virus inactive is gone. And so, what this study found was that people taking the drug, a proton pump inhibitor, as you said, Nexium, Prilosec, Protonix, Prevacid, there are a whole bunch of them on the market. They were twice as likely to test positive for COVID. And people taking these drugs twice a day as many people do, were three to four-fold more likely to test positive for COVID. And actually, Cynthia, I remember seeing this study, and it literally stopped me in my tracks. And I said to my husband, who is not a physician, he’s a cybersecurity counterterrorism person. I said, “Honey, you know that, if you’re on, like, Nexium, you’re more likely to have COVID.” And he looked at me, he was like, “Well, how would I know that?” Like, “What?” And I said, “Oh, you know, the stomach acid.” And he’s like, “Oh, okay, yeah.” And then I asked a friend who’s a dermatologist. She’s a dermatologist and a pathologist, and she was also like, “Woo, I didn’t know that.”


And then, of course, when you explain it to people and then Cynthia, I asked some of my GI colleagues, and they were like “Ha?” And then I realized that this drug, I mean if you think you’re prescribing a lot of it in cardiology, I mean, we’re just stamping it on every patient who comes through the GI clinic or endoscopy unit. It is difficult to leave a gastroenterologist’s office without a recommendation for a proton pump inhibitor.


So, the ones who are most recommending this were completely unaware of the risk. And this is when I said, “Okay, Public Health Service announcement.” And I started out wanting to just write an editorial for HuffPo or something and I thought, “Okay, I’ll write an editorial about the importance of stomach acid and how it confers this higher risk for viral infection.” And then my wonderful book agent has worked with me with the other three books, said, “Well, maybe there’s a book in here.”


And then right on the heels of that study, another study came out showing that the composition of the gut microbiome was the most important predictor of outcome from SARS-CoV-2 more than age, comorbidities, etc. And then I was like, “Okay, people don’t know this because people in my own medical community who are fantastic doctors, well educated, don’t know. So, what are the chances that the average person knows? And that started on my journey to writing book number four, The Anti-Viral Gut.


But stomach acid, I have a slide that I use in talks where it shows proton pump inhibitors and it has all these arrows going around, and it shows increased risk of dementia, increased risk of kidney disease, increased risk of bone loss and fracture, increased risk of pulmonary complications, pneumonia, etc., increased risk of infection, all of these things. And so, you think, “Okay, how can one drug cause all these problems?” And the reason is because this drug is blocking, it is literally shutting down the most important ingredient in digestion, which is stomach acid.


Without stomach acid, it is impossible for you to properly digest and assimilate those nutrients. And of course, if you think back to the early part of our conversation, the GI tract is the engine, it’s right in the middle. It’s providing the nutrients for all the different organs. So, when you see, okay, the engine is compromised. There’s no oil for the engine. You start to see how the brain is affected. The lungs, the kidneys, all the different organs are affected because the nutrient delivery to these other organs is compromised.


And so, somehow these pharmaceutical companies have convinced everyone, the physicians and everyone else, that we are overproducing stomach acid, which is just factually incorrect. Overproduction of stomach acid is a really rare condition called Zollinger-Ellison syndrome. Well, actually, I lie. I have seen cases of Zollinger-Ellison syndrome because when I was full-time at Georgetown, we had a joint appointment to the NIH. And all 3000 Zollinger-Ellison patients in the entire country are treated there because it’s such a rare disease, somewhere between 1 in 10,000 and 1 in a million people.


But this is not a condition you’d really ever come across in the normal course of your practice. And so, it’s a very rare condition of overproduction of stomach acid. But the other 300 million people in the country, it is not overproduction of stomach acid. It is that we’re doing things that we shouldn’t be doing. We’re eating late at night, we’re overfilling our stomachs, we’re drinking too much alcohol, we’re smoking, caffeine, all those things that cause that lower esophageal sphincter, that valve between the esophagus and the stomach to open inappropriately and let the acid come up.


But the acid level themselves are totally normal in 99.99999% of reflux. So, we’ve been sold a bill of goods by the pharmaceutical companies. We have been misled. And unfortunately, I think my GI colleagues have been complicit in that and convinced people that it’s a good idea to create a disease state in their gut with these drugs that then lead to lots of other problems. So, we can talk about the increased risk of infections, not just viral, but bacterial.


We also know that stomach acid is an important ingredient for maintaining that gradient. As we go from the mouth down to the bottom of the colon, the amount of bacteria increases in our gut. And that’s very intentional and that serves a very specific purpose. And so, now when we turn the stomach from an acidic hostile environment for bacteria into a nice friendly alkaline place for pathogens and bacteria to overgrow, we disrupt that balance.


So, really three big things. We dramatically interfere with digestion, we dramatically increase our risk of becoming infected, and we create imbalance, we create dysbiosis in the gut. So, I hope I’ve convinced everyone that acid blockers, other than for very specific indications like Cynthia referred to short term, you come in with a bleeding ulcer, things like that, or you’ve had a cardiac event and you have to be on some heavy-duty cardiac drugs that may cause some damage to the gut. Six to eight weeks, that’s what we’re talking about, what’s recommended maybe even just two weeks. But as you said, people are on these drugs for years, for decades.


Cynthia Thurlow: Yeah. And it’s interesting because I did both inpatient and clinical cardiology and the NP service in our cardiology group dealt with all the hospital follow-ups. And for anyone that’s listening, cardiac patients generally go home on a milieu of medications and Protonix is always part of that. And so, I would always start the conversation and just say, not all these medications are necessary long term. Some people wanted to be on as little as possible. Others were completely immune. They’re like, whatever you think I need to be on, I’m going to take. I’m not going to question anything.


The one other thing that I just want to tie in that you mentioned in the book that I think really will bring this home for people. PPIs or proton pump inhibitors are part of the top 10 most prescribed drugs in the world with annual sales of 14 billion dollars and 80% of people with prescriptions, it is unnecessary. So, if you’re on this medication, don’t stop it. Go have a conversation with your doctor, your healthcare practitioner. But understand that more often than not, these are designed to be used short term and not forever. Because of all the reasons that Dr. Chutkan just provided, this really impacts our ability to fight off pathogens, it impacts digestion, we can’t absorb nutrients quite as effectively and that’s quite significant.


Robynne Chutkan: Yeah. My GI practice has changed so much in the last decade and a half where I’ve gone from diagnosing more conventional GI conditions like colon cancer and gallstones and ulcers to things like dysbiosis and increased intestinal permeability, etc. But one of the things that is so dramatic is that I find myself in my practice spending so much time trying to undo the damage from these medications. So, I’m treating conditions that are in large part created by well-meaning medical colleagues who have people who are prescribing antibiotics unnecessarily or long-term, like putting people on antibiotics for acne.


They’re putting people on long-term PPIs; they’re putting people on NSAIDs. And so, it really is just trying to help people navigate when is a drug important versus not. And I 100% agree with you. Like, please don’t stop or start any new medication based on what we’re telling you here, which is for educational purposes. But please do have a pointed discussion with your healthcare provider, your prescriber, and ask some probing questions, like starting with. “Is this drug absolutely necessary?” Like, “What would happen if I weren’t on this drug?” You’d be shocked at how often the answer is, “Oh, yeah, it’s not necessary. Oh, nothing. You’ll be fine. You don’t have to take it.” And you’re like, “Okay, you’ve had me on this drug for 13 years. It’s ruining my gut, and now you’re telling me that, oh, it was icing on the cake. You don’t really need it.”


So, one of the things I do in the book, in The Anti-Viral Gut in the medication section and the plan is I go through each of these medications that are harmful to the gut starting with antibiotics. I go through proton pump inhibitors, nonsteroidal anti-inflammatory drugs, steroids, biologics, narcotics, all of them. And I recommend here are three or four really important questions to ask your doctor about these drugs.


And then here are some alternatives for how you can make them less damaging, whether it’s an alternate day dosing, a decreased dose, a different version, a different medication altogether, a different therapeutic intervention that’s not a drug because I really wanted people to have to not just be, like, the bearer of bad news, like, “Guess what? That NSAID is really ruining your gut. Got to just suck it up.” But what can you do instead. Do you find, do you look back when you were doing hospital-based medicine and think, “What were we doing? I have those moments a lot.”


Cynthia Thurlow: Oh, a lot, because as an example and I speak openly about this on the podcast, statin drugs, Zocor, Crestar, Lipitor, we prescribe routinely and all the time in cardiology. And I remember joking with a colleague and I always say, “Know better, do better.” So, this is something that my colleague and I were talking about. And because of the population that we’re seeing, we think statins need to be in the water supply. We actually said that. I mean, I cringe when I think about it. I did not say this in the context of being disrespectful. It seems like everyone needs them. And when both my parents were prescribed statins, I started to look a little more closely, because I noticed one of my parents cognitively, there was starting to be a noticeable shift in how sharp, my dad has always been this very smart person. And I started asking him, I said, I have this NIH researcher who’s a patient who said, “I refuse to take statins.” And that’s what set me down that rabbit hole because she had pointed me in the direction of some research. And the more I understood about the way that they worked in the brain and what happens with low cholesterol levels, I mean, all these things that we kind of took for granted, we would increase the dose until we got to certain numbers on the lipid panel. And that’s how we would determine whether or not it was efficacious or not.


And she really opened up my eyes and for which I’m forever grateful. But I noticed my mom started having a conversation with her providers about, are there alternatives? Can I be on less medicine? And she got off and was put on something else. And my dad was steadfastly like 80 g of Lipitor was what he was going to be on forever. And I’ve had conversations with his own provider about this and he wasn’t willing to stop the drug or decrease it.


And so, I oftentimes reflect on things that we knew at the time that were standards of care that I now look at a little differently. I’m like, “Wow, we’re looking at very myopically at one issue and not thinking about what the net impact was on taking this one drug, like whether it’s myalgias or muscle achiness or elevated CKs, creatine kinase. I mean, all these things that were happening that I think back down, I’m like, “Gosh, instead of really focusing on lifestyle first, we’re hitting patients hard with medicine to lower blood pressure, lower their blood sugar.” I mean, all the things that were standards of care in that environment.


But yet I think about, “Wow, the net impact of not having those discussions, not having the time to be able to sit down and to have those long discussions about the things you’re doing in your lifestyle that are impacting why you’re on so much medication.”


Robynne Chutkan: Or the knowledge. And as you said, that’s still the standard of care. I had this discussion on Saturday with a friend. He’s a urogynecologist and I’m good friends with he and his wife and we had a little double date playing squash and were having some dinner. After and chatting and he was insisting, “Oh, well, high cholesterol is just genetic. It’s just genetic.” Because I changed my diet and nothing happened. And I was like, “Well, you are one of the worst eaters I know. I’ve been on vacation with you. I hang out with you all the time. You’re always ordering a meatball grinder like essentially you eat a high fat, high animal protein diet, which might be fine for other reasons, but let’s talk about what that does to cholesterol.”


And so, when we think about who is doing the educating and I think most people don’t realize this that the vast majority of these studies showing a benefit of these drugs, they’re funded by the pharmaceutical company. And we’re not talking millions of dollars or even hundreds of millions of dollars. We’re talking billions of dollars, trillions of dollars when we get into biologics. And that is who is doing the educating and the marketing. There’s a fantastic book. It’s somewhere on my shelf behind me, but I can’t pull it. “Oh, look at that. I was able to pull it right out.”


Cynthia Thurlow: Perfect.


Robynne Chutkan: This book, Our Daily Meds by Melody Petersen. This book was written, give a shoutout to Melody Petersen, I have never met her. But this book was written in 2008, so what is that, 15 years ago? This book “Sorry, my OCD, I have to get it back in the bookshelf,” completely changed my perspective on medication. And it’s like, okay, “I’m a doctor. I trained at Yale and Columbia, Mount Sinai.” Really great institutions. I had no idea. So, in this book, Melody Peterson, who is a journalist, not a physician, describes the way pharmaceutical companies come up with these campaigns. And she talks about PPIs in there. So, they literally get together in a room and they’re like, “If we can convince everyone that they’re overproducing acid, we can convince them that blocking stomach acid is a great idea.” I’ve seen the same thing with dysbiosis. The whole term SIBO, small intestinal bacterial overgrowth was really coined with the encouragement of a pharmaceutical company that makes an antibiotic that is used off-label to treat this.


So, if they’re like, if we can convince everyone that they have too much bacteria rather than what’s really going on, which is they have an underrepresentation of healthy species, we can convince doctors to prescribe antibiotic. So, I ask patients, I’m like, “Do you think that something that was caused by too many antibiotics can be treated by an antibiotic?” If you ask a second grader that they’ll be like, “Nah that doesn’t make sense.”


If something’s caused by an antibiotic, can you use an antibiotic to treat it, the same thing that caused the problem? No. So, it’s overwhelming. And I think when I talk about this stuff, I probably sound like a crazy conspiracy theorist. Cynthia, you know this like, physicians don’t know. They don’t know that they’ve been indoctrinated. I was one of those KOLs as key opinion leaders and just quickly share my experience that I won’t say the company because I’m not foolish enough to do that and potentially get sued.


But I was a KOL for a large pharmaceutical company that everybody knows that made a drug for inflammatory bowel disease, one of my areas of expertise. And they went from saying, “Oh, here’s a slide set that our research team read– marketing team put together. If you’d like to use any of these slides, feel free.” Beautifully made professional slides. So, it’s like, “Oh, interesting. Okay, here are a couple I pick out.” They went from that to then saying, “Here’s a talk we created that we’d like you to use to then saying, this is a talk you cannot edit, alter, remove anything.”


And then I was like, “Okay, well, I actually don’t work for your company.” So, it was just very clear to me over my 30-year medical career, I saw it and experienced it is the takeover by the pharmaceutical companies for medical education. I was on the board of one of our large GI societies and I suggested at the board meeting that for our plenary session, we only invite people who have no conflict. Because I said, okay, you throw up a slide saying, I’m supported by Grants from blah, blah, blah, blah blah blah blah, blah, blah, therefore I have no conflict. I’m going to proceed with my very biased talk that’s been supported by hundreds of thousands of dollars from these companies and that’s not resolving a conflict.


So, when I made this suggestion, my colleagues all looked at me. They were like, well, there’s nobody to invite. Like, how could we have a plenary session with everybody basically is getting funding, everybody is on the take. And to think that you’re going to get a grant for $500,000 from this drug company, but it’s not going to affect what you recommend and what you do, that’s magical thinking.


Cynthia Thurlow: Yeah.


Robynne Chutkan: And so, we are being educated by key opinion leaders in medicine who are highly compromised, almost all of them. They’re educating all the other doctors and then the doctors are telling us what to do as consumers. I speak with my consumer hat on now, not my physician hat, until we really demand that we are not being educated by and the information isn’t sifting down through people who are highly conflicted, this is what we’re going to continue to get.


There is very little evidence that statins do anything in women, particularly women less than 60 who have no personal history of heart disease. So, if you were a woman, you’re 45 or 50, you have high cholesterol, your doctor puts you on a statin. You are going to get all the side effects of that statin including some of the things you talked about, potential issues with cognition, muscle aches, cramps, etc. With essentially no evidence that that statin is actually decreasing your risk for cardiovascular events.


But you in your wildest dreams, wouldn’t suspect that because you’re like, well, my doctor put me on it. So, she or he must know what they’re doing. Why would they put me on a drug that’s not going to help me? Because they have been marketed to and educated by the pharmaceutical company to believe that this drug is magic. So, it’s crazy what’s going on with medical education.


Cynthia Thurlow: It really is and it’s interesting. I probably haven’t spoken about this on the podcast before, but the large cardiology group that I work for, if we’re in clinic, there were always drug rep lunches. But if you partook in the drug rep lunch, you had to sign your name down. And generally, it was stuff I didn’t eat, so I would just politely, I was always very polite. “Very polite, thanks for coming in. I have my own lunch in their fridge. I’m going to grab it and then I’m going to go back to my office.”


And so, this one drug rep would ask me, “Why don’t you ever sit in on our educational series?” And I said, “Well, I understand why you want me to prescribe the new drug but I have five other generic drugs that work just as well in my patients and that costs my patients five times as much.” And you know they grew to respect me because I would just say, “Unless you have something that is so unique and so different, I’m not doing that to my patients because it’s an undue burden to them. If they’re already on 20 medications and they’re retired or they’re on a fixed income, what do you think that does to them?”


Robynne Chutkan: And let’s face it. Those lunch-and-learn things are just marketing. I mean, shame on hospitals for allowing pharmaceutical reps to come in and market, because all of this information about the drug is available at our fingertips to all of us, to physicians and consumers alike. So, the idea that we need to have our pharmaceutical sales rep come in to educate us is, again, magical thinking. But yeah, that is how it’s done. Good for you that you resisted.


Cynthia Thurlow: Yeah, well, I mean, it was because I was very respectful, because I was like, “I know you have a job to do and I have a job to do and with integrity, I cannot sit in on this knowing that you’re going to provide education that is not going to change the way I’m practicing right now.” And so, I would just leave it at that, and then I would go back to my room and eat my salad. But I want to make sure that we shift a little bit and talk about– we’ve mentioned dysbiosis, I think, kind of explaining it in larger terms, but also the estrobolome, which is this awkward term that yet is so important. I know from my female listeners, they’ve been asking. They keep saying, “Can you have someone talk about the estrobolome? That’s why it was so serendipitous when we’re emailing last night, I was like, “This is perfect.”


So, let’s discuss the importance of this. Why is it so important? What are some of the things that you see on testing with regard to the estrobolome that gives you ideas of whether or not it’s healthy and robust or is it compromised from all these lifestyle measures, the antibiotics, the chronic stress, synthetic oral contraceptives, etc.?


Robynne Chutkan: Yeah, it’s such a fascinating topic. So, you might hear it talked about as the estrobolome, estrobolome, estrobolome like microbiome. No right or wrong way to say it, but we’re– So, it’s Estro E-S-T-R-O-B-O-L-O-M-E. So, think of it like the microbiome. And so, what we’re referring to is this collection of bacteria in the GI tract that are very, very intimately involved with maintaining estrogen levels.


So, what does your GI tract have to do with estrogen that’s produced in your ovaries and your adrenal glands? So, let’s do a little anatomy and physiology. I promise not to get too complicated, but I want you all to know exactly how this works. So, estrogen is made in our ovaries and adrenal glands. And there’re a couple of different types of estrogens in the body, three different types. We don’t need to get into what they do, specifically each one.


But you know that estrogen is responsible for reproductive health, for libido, for weight management, if you will, for where you deposit fat typically. We have sort of a female pattern of fat distribution with more on our hips, buttocks, and breasts versus male. And that a lot of that has to do with differences in these sex hormones. But estrogens are also responsible for brain health and cardiovascular health and bone health and to some extent, cognition.


So, it’s not just things you think of typically as sex hormone stuff like reproductive health. So, these estrogens are made, they travel to– there are many different cells in the body that have estrogen receptors, not just the sex organs and our breasts, but we have estrogen receptors in the brain and the bone, etc. So, the estrogen travels to these different organs and then it gets recirculated through the blood to the liver. In the liver, the estrogen is conjugated, meaning it’s put into a form that’s ready for excretion.


And where does the estrogen get excreted? How does it get out of our body? The estrogen that’s been used up through our gut, we secrete it in the stool and through the urine. So, once the estrogen is conjugated in the liver, it’s put into the gut in bile. Remember, the liver makes bile. It’s stored in the gallbladder. It’s released into the small intestine. So, all estrogen gets into the bile in the small intestine in a conjugated form. And most of it gets excreted again through the stool or through the kidneys.


But this collection of bacteria in the gut, the estrobolome or estrobolome, they make an enzyme called beta-glucuronidase. And when you have a balanced, healthy microbiome, your levels of beta-glucuronidase are just right. That Goldilocks level of beta-glucuronidase just right, not too little, not too much, just right. And beta-glucuronidase allows some of the estrogen, it deconjugates it into a form where it can get absorbed back through the gut lining and into the bloodstream.


Remember, it came from the bloodstream into the gut by way of the liver. Came from the bloodstream, into the liver, secreted the bile, into the gut. So, some of it gets recirculated back out through the gut lining. But for that to happen, it has to be in this deconjugated form. And you need beta-glucuronidase for that to happen. Now, when we have a disrupted microbiome, typically we see overproduction of beta-glucuronidase. And what does the overproduction of b-glucuronidase mean? It means more estrogen is going to get reabsorbed into the gut than it should. And you are going to end up with a situation called estrogen dominance.


And so, you have a higher level of estrogen in your body than you should. And remember, it’s not just the amount, it’s the ratio. It’s estrogen to progesterone and that ratio is going to change at different times in your life, during menarche, when you first menstruate, when you’re menstruating, during perimenopause, and menopause. So, it’s never just the absolute number, it’s a ratio.


And so, we see estrogen dominance associated with a lot of conditions, with infertility, polycystic ovary syndrome, endometriosis, PMS, obesity, a wide range of things. It doesn’t mean it’s causation for all of these things. But there is an association. We can end up with too much estrogen also from xenoestrogens, which are estrogens in the environment, like in dry cleaning solutions and in certain fragrances and in pesticides. So, when we’re exposed to a lot of chemicals in the environment, we can end up with estrogen dominance that way.


And then there are phytoestrogens, which are estrogens in plants, in things like soy and certain types of tofu and tempeh, etc. So, there are all these different ways we can get estrogen. And again, we want balance, So, it’s this idea that we should have as much estrogen as possible, not exactly how it works. Too much estrogen can be associated with breast cancer, with other problems, too little estrogen can be associated with other problems.


So, we want just the right amount of estrogen for where we are physiologically based on how old we are, what’s going on with the rest of our bodies, etc. So, a premenstrual level of estrogen is not appropriate for a postmenopausal woman and vice versa. And that’s why it’s really important to look at things in context and not try and say, okay, I’m going to go back to when I was 20 years old because if you do that, you’re going to put things out of balance and you may end up with a problem, whether it’s heart disease or cancer or something depending on what it is you’re putting out of whack.


But that’s why the estrobolome is this collection of gut bacteria. And we don’t know all the different species that are involved, but if we look at it sort of big picture, we know that if your gut is healthy, your estrobolome is likely healthy, and you are balancing the amount of estrogen that you’re excreting versus reabsorbing and ending up with healthy ratios. And if your gut is really disrupted, you may end up with disrupted hormone levels there too. So, again, there’s so much interaction, it’s really impossible to look at the organ, the gut as a body, as just this one. We have the gut, then we have the brain, then we have the reproductive hormones. It’s all connected.


And to just make it more complicated, estrogen levels also can influence and impact what’s going on in our gut. So, it’s very much like the gut-brain connection where it’s bi-directional communication. Our brain can influence absorption of nutrients, secretion of digestive enzymes, production of gut hormones, and our gut can influence mood and levels of anxiety, etc. So, we see this bi-directional communication, and we see that same bi-directional communication very much through the estrobolome with the sex hormones and the gut.


Cynthia Thurlow: That is the best explanation that I’ve heard yet. So, thank you so much for so thoughtfully explaining that. And for anyone that’s listening, I think the big takeaway is, again, this concept of balance that if you’re worried about whether or not there’s a good balance in estrobolome, understanding that this gut piece is so significant. And for many individuals, I think we take for granted that periods are heavy. We take for granted that fibroids are common. We take for granted that infertility is, unfortunately, becoming increasingly more prevalent. We take for granted that we make these assumptions that if you’re a woman in perimenopause at the tail end right before menopause or menopause, you’re not making as much estrogen, so this can’t be a problem.


And it is, in fact, something that can be a lifelong issue. And I think maybe perhaps touching on you’ve mentioned the antibiotics, other things that can impact the balance of beneficial to nonbeneficial bacteria. And I’m thinking about things that genetically modified foods. I’m thinking about alcohol. Alcohol is something that I talk quite a bit about because now there’s this merging research about the fact that alcohol, despite what the alcohol industry, the wine industry in the United States would like us to believe that there aren’t as much benefits to regular consumption to alcohol as what we once actually thought.


And what are some of the things that you’re seeing in your patients for those that are drinking quite a bit? I know coming off of the tail end of the pandemic, I know that my own patients and clients were very transparent about how their alcohol consumption had changed. In many ways, just being very sad about the changes that occurred. But the dietary contributions and contributions of habits like alcohol consumption that can impact things negatively.


Robynne Chutkan: Cynthia, I love that you focus so much on three of the things that are important for overall health and specifically for gut health, and that’s alcohol, sleep, and exercise, these are key. If were to look at the biggest factor that influences a microbiome in adults, it would be diet. And we’ll definitely spend some time talking about that. And the interesting thing with diet, it’s not so much the presence of certain things that are bad, it’s the absence of enough plant fiber. But of course, ultra-processed foods are a whole different category because they have emulsifiers and things in them that are actively destroying gut bacteria, actively damaging the gut lining. So, it’s not just like, okay, you didn’t eat enough fiber today. It’s like you ate a bunch of chemicals that are ruining your gut. So, diet is probably the biggest factor in terms of influencing the microbiome.


The second would be the medicine cabinet. And we talked about a lot of those drugs, antibiotics, acid-blocking drugs, steroids, etc. I have to count alcohol as a separate category a little bit because let’s face it, alcohol is not food really. And before we had antibiotics, we had alcohol. That was how we sterilized things. I mean, I wasn’t around back then, pre-penicillin in the 1920s and early part of the century. But think about when you go to get blood drawn. They still use an alcohol swab to clean your skin. Why? Because that’s how they kill off a lot of microbes in the skin to make sure you don’t get an infection.


So, alcohol is a toxin for the body. It’s important to just acknowledge that. Now, if you are a very healthy person, you can probably get away with drinking a little bit of alcohol every now and again, and that amount varies. So, for example, in Britain, they will tell you, according to their guidelines, that in women, fewer than one drink a day. So, six or fewer drinks a week is probably okay. In Canada, they came out recently and said there’s no amount of alcohol that’s safe for health. In the US, we again are very much influenced by our lobbyists, so the number is a little higher.


But what I want you to understand is when we say this might be safe, meaning you can get away with it, and this is probably not going to, the likelihood of this causing a serious disease is low, but understand, it is still contributing to that. So, almost every cancer in the body, and certainly the digestive cancers, esophageal, stomach, pancreatic, colon, alcohol is a significant risk factor, okay. And that’s just what the data shows us. This isn’t my opinion. It’s a significant risk factor. And then, of course, for other cancers, for breast, etc. But just sticking to my neck of the woods with digestive cancers is a major risk factor for virtually every cancer of the digestive organs. And that’s because alcohol is metabolized to acetaldehyde, which, as it sounds, is the first cousin of formaldehyde, it’s a known carcinogen like asbestos, nicotine, etc. And so, what you have to think about is limiting your consumption or not having any. So, if we think about smoking, we know that if you’re smoking less than a cigarette a day, your risk is lower, but it’s not zero.


And we wouldn’t suggest like, “Oh, well, just smoke one cigarette a day and you’ll be okay.” We tell people, “Don’t smoke.” Because smoking is harmful to our health. So, I think the message really should be that we shouldn’t be drinking because it’s harmful to our health. Now, that’s difficult to do right and I’m not a teetotaler. I aspire to be one, but I’m not quite there. But in my case, I have a strong family history of Alzheimer’s. And so, it’s clear that alcohol is a contributing factor. It’s not just like you get this set of genes, and you get Alzheimer’s It’s all the things that contribute, and our diet contributes. Whether we exercise or not contributes, how actively we use our brains contributes and how much we drink contributes.


And so, it’s just very important to have honest conversations about this without judgment, without blame. But encouraging people to look closely at these risk factors and decide, is this something that I’m better off eliminating because it’s not serving me and it is contributing to my already high family history of Alzheimer’s or stomach cancer or whatever it is? Or on a personal level, I have a disrupted microbiome and I don’t feel well or I have an autoimmune disease, whatever it is, and this is clearly not contributing.


So, trying to suggest that alcohol is good for us is just factually correct. We really don’t have the evidence to suggest that it provides significant health benefits, and we have a lot of evidence to suggest that it is detrimental to our health, particularly in larger amounts. So, there’s alcohol. Exercise is an important contributor to the health of the microbiome as well as to just gut function. The GI tract is a long tube of smooth muscles. So, unlike skeletal muscle like our biceps or triceps, which is under voluntary control, it’s under involuntary control.


But that being said, if we are not moving, movement encourages peristalsis. And that’s the whole goal, right, is to get the products of digestion from north to south. So, if we’re not moving, our bowels are probably not moving either. We’re having a lot of stagnation in the digestive tract, which is a contributor to dysbiosis, and also just causes constipation and bloating, etc. And then there are also some more complex pathways to do with nitric oxide. But exercise, an important stimulator of peristalsis and a contributor of gut health.


One that people forget about is exposure to nature. Getting outside, that’s a really important one. We know from the Spanish flu epidemic over 100 years ago that something called an open-air factor was we saw that soldiers who recuperated outside and the open air, on cots had much lower morbidity and mortality than the officers who were recuperating inside the hospitals.


And if you think back to the early days of the pandemic where we said, “Okay, it was safe to socialize outside but not inside.” So, that’s about transmission. We know transmission is lower outside, but it turns out recovery is also faster outside. And there’s something the open-air factor is defined as the germicidal constituent in open air that is harmful to pathogens like SARS-CoV-2, tuberculosis, etc.


So, getting outside is good for us if we’re trying to avoid pathogens. It’s good for our mood. We know about the Japanese process of forest bathing, Shinrin-yoku that increases endorphins, is good for our heart health, our mental health, etc. It turns out it’s good for our immune health. So, that’s an important piece of it too. Stress, you may not be able to do much about a stressful situation, but you can actually how you train your body to respond to that stress can have a profound impact on the microbiome. There’s a very famous study done in college students where they looked at during stressful times, which for college students was exams. Levels of certain pathogenic bacteria increased 1000-fold within an hour when these students were stressed. It’s crazy, right? So, you think about how you get sick when you’re stressed and the lack of sleep. We know from the British Medical Journal, from an article published there, that people are chronic as sleep deprived, had an 88% increased risk of coming down with COVID.


So, these things that Cynthia talks about, they’re real. They’re not just these abstractions that she’s like, “Oh, let’s talk about.” These are real things that we see validated every day in our scientific literature, as well as with the patients who we see on a daily basis, who are stressed, who are sleep deprived, who are drinking too much, who are not getting outside, and they’re sick, they don’t feel well. So, these are things that we can all do. We don’t need a physician to help us get outside or get more sleep or these are things that we can resolve to do that have a tremendous impact on our gut health and our overall health.


Cynthia Thurlow: Well, and it’s interesting, I’m thinking about my 17-year-old who had both an AP Calc and then an AP computer science exam on the same day. So, every kid across the United States that has these AP exams has them on the same day. And I said, who in their right mind thought that was a good idea? And he had an SAT on Saturday and a prom, and then he had an AP history exam on Friday. And so, I kept thinking clearly these are people that are not realizing the net impact. So, I kept saying you just need to get over the hump of today and then you’ll have all of it behind you.


But I can just imagine, I’m sure he probably this week, given all the excitement of exams and prom and SAT, he probably very likely will have a significantly lowered immune response and susceptibility, not sleeping as much as he should be for sure. Now, I know when you were writing the book, I think I heard on another podcast that you had 60 pages devoted to sleep. And I would be remiss if we didn’t just quickly talk about the role of sleep because I am a huge advocate and very protective of my sleep. But what is the net impact of low-quality sleep or not enough sleep on our immune function as well as the health of our gut and our gut microbiome?


Robynne Chutkan: I really went down a rabbit hole with sleep and part of it was and I just love to give a shoutout to other authors. Matthew Walker, who’s a neuroscientist who wrote a book called Why We Sleep and Sean Stevenson also has a great sleep book. And you think about these things separately but really realizing the connection between sleep and the gut. So, let me just put it in perspective. If I were to not eat food for seven days, I would be hangry, but I would be fine. Really cranky and hungry and then on the 7th day I’d eat some food and I’d be fine.


If I were to not drink water for seven days, my kidneys may start to see the early signs of my kidneys shutting down, some kidney dysfunction by day seven, the creatinine going up from severe dehydration. But once I got rehydrated, I would probably be okay, not have any long-lasting kidney damage. If I didn’t sleep for seven days, I would do such overwhelming damage to my body, my brain would have aged, my libido and reproductive health would be affected, my bone health, my cardiovascular health, my risk for a cardiovascular event would skyrocket.

So going without sleep, sleep is really the magic elixir. And the reason why is that sleep reboots our whole system and particularly our immune system. That’s why we sleep. I mean, think about it. Sleep has been preserved over millions of years because it confers a survival advantage. And so, there are lots of these sorts of landmark studies. There was one done through Carnegie Mellon where they exposed sleep-deprived individuals to common cold, a different kind of coronavirus since SARS-CoV-2. And they had groups who were sleep deprived and groups who were not. And they did the same thing with stress versus not. And the sleep deprived and the stress group much more susceptible. And of course, sleep deprived and stressed, the worse because remember, most of us are exposed to the exact same viruses. But the reason why one person becomes sick and is severely symptomatic versus another person might not get infected at all or have mild symptoms doesn’t really have anything to do with a virus. It has to do with us as hosts and our host defenses.


And so, sleep is one of those things that really allows the immune system to reboot for the T cells to regenerate and take their place and get back ready to do battle. So, if you are not sleeping, your immune system is at half-masked and you’re not able to protect yourself and defend yourself properly. The vaccine data was fascinating. Study found with the COVID vaccine and this study had been done with hepatitis B vaccine and influenza vaccine, it found that “If you were sleep deprived in the two days before the vaccine, you had a 50% lower response rate.” Crazy, right. And I remember, my daughter is a rower and she was in the middle of her summer rowing season regattas when she was supposed to get her vaccine. And she was getting up at 04:00 in the morning and I was like, “No, we got to reschedule this. You can’t get the vaccine because you haven’t slept in four days, you haven’t slept properly, and it’s less effective.”


So again, these are the things that I don’t think people know. They think, “Oh, you just get a vaccine and it works.” It doesn’t have anything to do with what’s going on in your body, but something as simple as being sleep deprived or not, because remember, what the vaccine is doing is it’s mounting an immune response. It’s getting those T cells and B cells, plasma cells to do something.


So, if they are basically exhausted because they haven’t slept in two days just like you are, they’re not going to be able to get up and do their thing any more than I would be able to get up and run a marathon on 5 hours sleep. So, that performance that we see in our own bodies when we are sleep deprived, when we are hungover when we are not hydrated, is the same thing for our microbes and our immune cells, etc. And when you think about it that way, remember, your microbiome is the largest ecosystem in your body.


So, when you think about it as an ecosystem, as a community, you’re like, “Okay, I got to take care of this community. I got to be kind to this community. I got to make sure this community is sleeping, resting, getting good nourishment, all of these different things.” And then you realize how it’s all connected and how all these different things. If you have the right inputs, you’ll have the right outputs, and things will work well for you.


Cynthia Thurlow: Well, thank you for putting all these invaluable connections together for my community. Just real, quickly, I want to be respectful of your time. The Anti-Viral Gut book is one of my favorites that I read in 2022 and then I reread it over the weekend to prepare for this. Give me your top three tips for ensuring that we are investing in a healthy gut microbiome. If there are top three things that you would say and obviously you go into explicit detail, I think at least 40% of the book is really talking about your plan. So, I think it’s very tangible. I think one of the things that I now really appreciate having written a book is making sure the information is accessible and then people don’t have to go down a rabbit hole of buying a bunch of supplements. You really focus on the food and that’s part of the message that I think is so helpful. What are your top three tips if your three big takeaways from this interview that you can do right now, today, or tomorrow that can improve the quality of your gut microbiome?

Robynne Chutkan: The food would be number one. Eat more plants. And it doesn’t matter whether you are a vegan, a vegetarian, a lacto-ovo vegetarian, omnivore, a straight-up carnivore. The American Gut Project study from 2018 looked at over 10,000 people globally to find out what was the most important predictor of a healthy microbiome. And it was the variety of plants that people ate, with a magic number being 30 or more different plant foods per week. And before you’re like 30 plants, let me remind you we’re talking not just about vegetables and fruits, but about whole grains, nuts, seeds, herbs, spices, legumes.


So, I can take a bowl of oatmeal and I can use some almond milk, oats, I can add some walnuts, pumpkin seeds, raisins, berries, shaved coconut, a little maple syrup, and cinnamon. That’s nine plants. You can get credit for the maple syrup. Just don’t overdo that, right. Just a little sprinkle. So, that’s nine plants. Think about what you can do with a salad. Lettuce, tomato, cucumber, carrots, chickpeas, brussels sprout. I mean, keep going. And don’t forget the parsley, the basil. You get credit for all of that. So, the diversity of plants I see even vegans in my practice coming in saying, “Oh, I eat vegetables every day, but they’re eating the same carrots, peas, broccoli in heavy rotation.” So, number one, I want you to eat more plants, and I want you to eat a diversity of plants. Ideally, get out to the farmers market if there’s something near you and buy a plant you have never eaten before and figure out what to do with that rutabaga. Ask the person at the farmers market who’s selling it. They’ll be able to help you. So, eat more plants, number one.


Number two, and I cannot stress this enough, judicious use of medications. Every single medication you take has a potentially negative effect in your body. Even prenatal vitamins do things to us that are not great. So, everything you take there was a study published in the Journal Nature, also in 2018, they looked at 41 different classes of drugs and they found that 19 of them had deleterious effects on the gut. And some of them are obvious. We talked about antibiotics and proton pump inhibitors. But laxatives, there was a big study from Britain earlier this year that showed that people who were regular users of laxatives had as much as a 65% increased risk of dementia. So, remember, when you affect the microbiome, you affect the brain. Most of the serotonin, the feel-good hormone, and many other neurotransmitters that our brain relies on are produced in the gut.


The Nurse’s Health Study showed us a study from 2022 where they looked at over 15,000 nurses, and they found that those who are using antibiotics for more than two months, cumulatively, not two months at a time. So, if in midlife, which they described as the 50s, you had a cumulative use of more than two months of antibiotics, which may be two weeks of antibiotics, a year times four years, that was equivalent to aging your brain three to four years. So, remember that gut-brain connection. It’s not just about destroying the mucous layer in your gut and putting holes in your gut lining and blocking your stomach acid and how that’s going to affect your gut. It is going to affect your brain. So, judicious use of antibiotics, number two.


Number three, I would have to say is “Get out and get dirty.” Because this has to do with gut health, mental health, feelings of well-being. And where do we get our microbes from? Well, “We get them from our mothers when we’re born, particularly those of us who are lucky enough to be born vaginally and pass through that birth canal, we swallow a mouthful of microbes, become our founding species.” And then we get them, babies put everything in their mouths, and that’s for a reason. They’re trying to rewire themselves. They’re trying to get germs into their body so they can build their microbiome.


So, our job as adults is to sort of guide them, right, like, “Yeah, don’t put that person’s shoe in your mouth.” But they do that because that is built into their DNA as a way to try and build their microbiome. And so, we get microbes through exposure to soil. And there are lots of studies showing that in very urban areas where there’s a lot of glass and concrete, our microbes on our skin, for example, are very different.


We’re colonized with more staph, and that’s why we see more eczema, we see more asthma in urban areas. So, there’s so much literature now showing that what we call exposure to urban areas, that rurality is a term I was looking for, is protective against autoimmune diseases and lots of other things. So, we want to get dirty. We want our kids to get dirty. Get out in nature, play, sit on the grass. All you can do is open a window and let some microbes in. Yes, pollen is going to come into this time of year, but the open-air factor, the exposure to microbes, getting dirty is really, really important. So, those would probably be my top three is, eat more plants, judicious use of medications, and get out and get exposed to some soil.


Cynthia Thurlow: Well, truly an invaluable conversation. We’ll have to have you back for a second round. Please let my listeners know how to connect with you, how to get The Anti-Viral Gut. I have Gutbliss on order because I want to dive down another rabbit hole for you. Please let them know how to connect with you on social media, how to get your book. And like I said, we’ll have to have a round 2 for sure.


Robynne Chutkan: Oh, I would love to. And if you’re in DC, I want to meet you. I know you’re in Virginia now. You’re in– [crosstalk]


Cynthia Thurlow: Yes. I’m outside of Richmond.


Robynne Chutkan: -you are near Charlottesville-


Cynthia Thurlow: Yeah.


Robynne Chutkan: -or outside Richmond.


Cynthia Thurlow: Yeah.


Robynne Chutkan: So, if you’re making a trek into DC, let’s definitely get together so you can find me at gutbliss.com G-U-T-B-L-I-S-S dotcom on Instagram @gutbliss, I do free office hours. It used to be Tuesdays at noon. It’s now Wednesdays at 03:00 P.M. Eastern Standard Time and it’s generally an hour. I do a different topic for the first half hour, and then I take questions. Last book is The Anti-Viral Gut. The one before that was a quickie. The Bloat Cure: 101 Natural Solutions for Real and Lasting Relief.


The second one, The Microbiome Solution, is a deep dive into all things microbiome. And the first one, Gutless, is a little how-to manual. What’s going on in your gut? What are all these different organs doing? So, I’d love to hear from you, Cynthia. I really want to thank you for the amazing work you’re doing, having people like you who come, who have that clinical background, medical background, and are taking all that experience and information, but broadening it and deepening it to really show people the path forward. Honestly, it’s so valuable. So, thank you so much for allowing me to be a part of it and keep on doing all the great work you’re doing.


Cynthia Thurlow: Thank you. Likewise. I receive that.


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