Show 1336: How the Antiviral Gut Tackles Pathogens from the Inside Out (Archive)

This week our guest is gastroenterologist Robynne Chutkan. She explains how keeping our digestive microbiota in good health can help our immune systems fight off pathogens from the inside out.

At The People’s Pharmacy, we strive to bring you up to date, rigorously researched insights and conversations about health, medicine, wellness and health policies and health systems. While these conversations intend to offer insight and perspective, the content is provided solely for informational and educational purposes. Please consult your healthcare provider before making any changes to your medical care or treatment.

How You Can Listen:

You could listen through your local public radio station or get the live stream at 7 am EST on Saturday, Nov. 29, 2025, through your computer or smart phone (wunc.org). Here is a link so you can find which stations carry our broadcast. If you can’t listen to the broadcast, you may wish to hear the podcast later. You can subscribe through your favorite podcast provider, download the mp3 using the link at the bottom of the page, or listen to the stream on this post starting on December 1, 2025. You will find this show well worth your time!

What Determines Host Health?

During the COVID-19 pandemic, we could all see big differences in who got sick and who seemed more resilient. Our immune systems are critical in determining just how susceptible we may be to infectious viruses like SARS-CoV-2. But what shapes our immune response?

What we need is an immune system that reacts just the right amount. This “Goldilocks immune system” meets both internal and external threats without becoming overly exuberant. If the immune system fails to react adequately to external threats, like germs, we come down with an infection.

Conversely, if it overreacts, we end up with allergies, sometimes very severe allergic reactions. In the case of internal threats, an overreaction leads to autoimmune conditions like Crohn’s disease. Lax response to an internal threat could allow a tumor to get out of hand.

A hefty proportion of the immune system is localized in the vicinity of the digestive tract. As it turns out, the balance of microbes inside the gut has a significant impact on how the immune cells just outside the gut behave. Keeping the microbes balanced can help the immune system control pathogens from the inside out.

Tackling Pathogens from the Inside Out:

Even before the pandemic, lots of people wanted to know how to optimize their immune systems. That desire is only stronger now. Surprisingly, we can make a lot of progress with some very simple steps.

Check the Medicine Chest:

To start with, we should all be considering the medications we take. Quite a few common medicines can disrupt the gut microbiota. Proton pump inhibitors like omeprazole (Prilosec) or esomeprazole (Nexium) are not kind to digestive microbes. Neither are pain relievers like ibuprofen or naproxen. Besides disrupting the microbes, NSAIDs like these can irritate the lining of the gastrointestinal tract. Sometimes they are necessary. When they are not, they should be avoided. We could say the same for antibiotics.

Our guest is a gastroenterologist. She understands the impact of pharmaceuticals on our digestive tracts better than most other physicians we have talked to. You will not want to miss her insights!

Feed Them Fiber:

Feeding our microbes what they need is crucial to keeping them healthy so that they can signal our immune systems properly. What microbes like is fiber, so a diet that leans heavily on plants is best. They also like variety.

According to Dr. Chutkan, one study found that people who consume foods containing at least 30 different types of plants each week have the healthiest balance of microbes. She gives an example of oatmeal (one plant) with blueberries, coconut and walnuts (three more plants), served with almond milk (one more plant) and cinnamon (another plant). That brings the total up to six types of plants in one bowl. (Adding maple syrup gives one extra!)

Other Essentials:

There are some other practices that are crucial for keeping our immune systems in tune so they can manage pathogens from the inside out. Getting enough sleep helps reboot the immune system. So does physical activity, especially when it takes you into nature. Exposure to dirt sounds counterintuitive, but it can really help your immune system hum. Moreover, being outside is often a good way to address your stress. Dr. Chutkan cited the Japanese practice of “forest bathing” as a good way of de-stressing and helping the immune system.

Healthy and Delicious:

Finally, Dr. Chutkan shares some of her favorite recipes with us. There are lots more in her wonderful book, The Antiviral Gut, with its detailed plan for improving our microbial balance and immune response.

This Week’s Guest:

Robynne Chutkan, MD, a board-certified gastroenterologist, is a faculty member at Georgetown University Hospital and is the founder of the Digestive Center for Wellness, an integrative gastroenterology practice located in Washington DC. Dr. Chutkan is the author of the digestive health books Gutbliss, The Microbiome Solution, The Bloat Cure and The Anti-Viral Gut: Tackling Pathogens from the Inside Out.

An avid squash player, runner and yogi, Dr. Chutkan is passionate about introducing more dirt, sweat and vegetables into people’s lives. She also hosts the marvelous Gutbliss Podcast:

The Gutbliss Podcast

https://robynnechutkan.com/about/robynne-chutkan-md/

Listen to the Podcast:

Download the mp3, or listen to the podcast on Apple Podcasts or Spotify.

Transcript of Show 1336:

A transcript of this show was created using automated speech-to-text software (AI-powered transcription), then carefully reviewed and edited for clarity. While we’ve done our best to ensure both readability and accuracy, please keep in mind that some mistakes may remain. If you have any questions regarding the content of this show, we encourage you to review the original audio recording. This transcript is copyrighted material, all rights reserved. No part of this transcript may be reproduced, distributed, or transmitted in any form without prior written permission.

Joe

00:00-00:01

I’m Joe Graedon.

Terry

00:01-00:05

And I’m Terry Graedon. Welcome to this podcast of The People’s Pharmacy.

Joe

00:06-00:26

You can find previous podcasts and more information on a range of health topics at peoplespharmacy.com. Some people are resilient and resist infections. Others are especially vulnerable to colds, flu, and COVID. This is The People’s Pharmacy with Terry and Joe Graedon.

Terry

00:34-00:46

What accounts for the differences in our immune systems? Why are some people so prone to infection, while others have an overactive immune response that causes damage? Does our digestive tract play any role?

Joe

00:47-00:56

Dr. Robynne Chutkan is a gastroenterologist who’s been asking these questions for years. Her book, “The Antiviral Gut,” offers advice.

Terry

00:57-01:03

Why is gut health so important to immunity? How can we eat to enhance our digestive microbes?

Joe

01:03-01:09

Coming up on The People’s Pharmacy, tackling pathogens from the inside out.

Terry

01:14-02:28

In The People’s Pharmacy health headlines: Many women would appreciate a little help losing the baby weight after giving birth. A Danish study shows that they are increasingly turning to GLP-1 drugs like semaglutide during the postpartum period.

The scientists analyzed records on almost 400,000 pregnancies in Denmark between 2018 and 2024. During that time, use of a GLP-1 medication within the first six months after giving birth increased quite markedly. By 2023 and later, about 90% of these prescriptions were for the weight loss formulation, Wegovy. Earlier in the study, women who had diabetes prior to pregnancy were most likely to have a prescription. In the later part of the study, the motivation for taking semaglutide appears to be weight loss.

The researchers caution that this early postpartum period is one of physiological and hormonal transition for the mother. The safety of semaglutide for breastfeeding infants has not been well studied. They urge their colleagues to conduct targeted studies on the best use of these medications for postpartum weight loss.

Joe

02:29-03:27

The makers of GLP-1 receptor agonists have been expanding their horizons. Research has suggested that drugs such as liraglutide, semaglutide, and tirzepatide may be helpful against a wide range of health conditions, including cardiovascular disease, chronic kidney disease, polycystic ovary syndrome, and non-alcoholic fatty liver disease.

The maker of Ozempic and Wegovy was also hoping that its semaglutide medication might help ward off Alzheimer disease. That’s because animal studies and epidemiological data had suggested such a possibility. But two new studies failed to demonstrate benefit for people with dementia. Volunteers were given oral semaglutide or placebo and tracked for about three years. People taking semaglutide did not fare better than those on placebo.

Terry

03:28-04:46

Cardiology experts have spent a great deal of time coming up with risk calculators. These are supposed to predict a patient’s likelihood of a heart attack. A new study of people who had heart attacks suggests, though, that atherosclerotic cardiovascular risk calculators are not as helpful as expected. The idea was that these tools would allow cardiologists to focus on people most likely to benefit from treatment such as statins.

But analyzing medical records of 465 people, 65 years old or younger, who had experienced a heart attack showed that only 10% of them fit the high-risk category before the event. A newer, different risk calculator called PREVENT would have identified only 3% as high-risk, although 23% were at intermediate risk. Most patients experience symptoms such as chest pain or shortness of breath only shortly before the event. If they’d been evaluated more than two days before their heart attack, the doctor would not have predicted the pending event.

According to the authors, these risk assessment tools are good at the population level, but they may not help doctors treat individual patients more effectively.

Joe

04:47-05:55

Doctors often perform surgery or place stents in patients with blocked carotid arteries. The surgical procedure is called an endarterectomy. It’s frequently performed on patients who have not experienced symptoms even though the blockage is visible on scans. Two large studies published in the New England Journal of Medicine compared stenting and surgery to medical therapy.

Both trials lasted four years, and each contained over 1,200 patients with asymptomatic but substantial blockage in their neck arteries. Patients who received stents had significantly fewer strokes than those who received medications, but there was no significant difference in stroke outcomes between surgery and medical therapy.

An editorial that accompanied the research concluded that there is no longer a role for routine carotid endarterectomy in persons with asymptomatic stenosis.

And that’s the health news from the People’s Pharmacy this week.

Terry

06:14-06:17

Welcome to the People’s Pharmacy. I’m Terry Graedon.

Joe

06:17-06:32

And I’m Joe Graedon. Why did some people seem especially vulnerable to COVID-19 while others barely experienced any symptoms? What factors determine who’s susceptible to various infections and who is resistant?

Terry

06:33-06:44

Our immune systems play a crucial role in establishing our vulnerability. But what influences our immunity? How do our diet and lifestyle impact our immune systems?

Joe

06:45-07:20

To learn more about the immune system and how it’s affected by our GI tract, we are talking with Dr. Robynne Chutkan. She’s a gastroenterologist and a faculty member at Georgetown University Hospital. Dr. Chutkan is the founder of the Digestive Center for Wellness, an integrative gastroenterology practice located in Washington, D.C.

Dr. Chutkan is the author of the digestive health books, “Gutbliss,” “The Microbiome Solution,” “The Bloat Cure,” and most recently, “The Antiviral Gut: Tackling Pathogens from the Inside Out.”

Terry

07:22-07:25

Welcome back to the People’s Pharmacy, Dr. Robynne Chutkan.

Dr. Robynne Chutkan

07:26-07:28

Thank you so much for having me. It’s great to be back.

Joe

07:29-08:23

Dr. Chutkan, we just love your new book, The Antiviral Gut. And I have to say, when I was in graduate school, I remember one lecture in particular on immunology. And the professor said, well, if we were to infuse rhinoviruses into the heating and air conditioning system of this room so that those viruses were spread out across the entire room, everybody was breathing in rhinoviruses. Not everybody would catch a cold.

Our immune systems are amazing, but some people are more vulnerable than others. Can you tell us about this idea of why some people rarely get sick or barely have symptoms and others seem to catch just about everything that comes down the pike?

Dr. Robynne Chutkan

08:24-09:51

Well, you hit the nail on the head with the entire theme of the book. And if I could sum it up in one sentence, it would be that host health matters, that we as the hosts who are hosting these viruses, our health, the strength of our immune system and other things going on in our body, many of them located in our gut, actually determine who gets sick when exposed to a virus. And that’s true of rhinovirus, it’s true of SARS-CoV-2, it’s true of HIV, Ebola, our immune system and other host defenses determine whether we’ll even become infected when we get exposed. And if we do get infected, also determine whether we’ll be mildly [symptomatic], have no symptoms, have severe symptoms, or possibly even succumb, and who will end up with post-viral symptoms.

So all of this isn’t random. And it’s not due to the virulence of the virus. In your professor’s case with that experiment, he’s talking about the same rhinovirus that everybody would be exposed to. And we see within populations, everybody exposed to the same SARS-CoV-2, the same variant with the same degree of virulence, but we see widely varying degrees of host resilience and host susceptibility.

And so really the whole point of this book was to highlight for people that there are things that we can do to be healthier hosts and to be more resilient to viruses.

Terry

09:53-10:04

Dr. Chutkan, I wonder if we have any idea what the most important factors are to determine who is resilient and who is really susceptible.

Dr. Robynne Chutkan

10:06-15:04

Terry, it’s such a great question. And a lot of the answers lie within that gut immune connection.

So when I was in medical school, I didn’t really have a very good sense of what the immune system was. It was a sort of ethereal concept of like immune factors and cells floating around somewhere in the body. But I don’t think any of us were really sure where that was. It turns out that the vast majority of the immune system, about 70 to 80% of it is located in the gut. It is literally along the gut lining.

So you have the trillions of microbes on the inside of the gut, which of course is outside of the body. And then just across that razor thin lining, one cell thick, you have all these immune cells and processes.

And it really is a hand and glove relationship. Those microbes are communicating with the immune cells across the gut lining. And they’re literally guiding and modulating the immune system. They’re telling them when to react, when to stand down, when to mount a big response versus a little response.

And so you start to see that if you have a disruption in the microbiome or a disruption in the gut lining across which they’re communicating, you’re going to end up with a disrupted immune system.

And so that gut-immune connection is really key. There are other important host defenses, stomach acid that doesn’t just help digest food. It also unravels viral protein that gets into the body. We often, we swallow these viruses as a very common, you know, we can breathe them in and they get into our lungs or we can swallow them.

And in fact, we have about 100 times more of those ACE2 receptors that bind SARS-CoV-2 in our GI tract compared to in our lungs. So it’s a common, the GI tract is a common portal of entry, if you will. And it explains why so many people with COVID have GI symptoms. So if you have stomach acid, that affords you an additional layer of protection.

There was a study that came out in 2020, a population-based study looking at 53,000 people. And that study asked a simple question. Does being on an acid-blocking drug like a proton pump inhibitor increase your risk of COVID? And the overwhelming answer was yes. And in fact, people taking a proton pump inhibitor once a day had double the risk. And people taking a proton pump inhibitor twice a day, as many people do, had three to four times the risk.

And while that seems sort of like, you know, wow, hot off the press, we’ve known for decades that these drugs, these acid blocking drugs, and the three of us have had many conversations about acid blocking drugs.

So we’ve known for decades that they increase the risk of certain infections, enteric infections, meaning infections that affect the gut. So not just SARS-CoV-2, but other viral infections, foodborne bacterial infections, because that stomach acid is really a critical host defense for unraveling viral protein, for killing unwanted bacteria that can get into our bodies through our GI tract. So there are other considerations like that.

The gut lining, you know, it’s this one cell thick lining, but it’s really the only thing protecting us from the outside environment because our GI tracts, and you know, this is such an interesting concept. I didn’t think about this at all when I was in my GI training. I have to admit, it was only about a decade or so ago that I began to realize that when you eat food and it travels down through, you know, down that digestive superhighway, those products of digestion that are in our gut are not in our body. They’re in this hollow tunnel that runs from our mouth all the way down to our anus. And food has to get absorbed through the gut lining to get into our bodies, to get assimilated inside.

And so the point of that gut lining is to act as a selective barrier to allow those important nutrients, once they’re properly broken down, to be assimilated into our body. Waste from cells gets excreted through the gut lining in the other direction. And of course, dead red blood cells, bacteria, et cetera, everything gets excreted out. And so toxins, viruses, pathogens from the environment that we swallow are in that gut lining. And a big role of the gut lining is to keep them out of the body, to keep them just there in the GI tract so they can be excreted.

And we know that we excrete SARS-CoV-2. In fact, we see fecal shedding of the virus, meaning we’re excreting it in stool, much, much long after we are able to detect it from the nose. So it continues to be excreted in the stool in people who have COVID after a nasal swab, et cetera, would be negative. And so we want that intact gut lining to make sure that these pathogens that we swallow end up in the toilet bowl and not inside our bodies.

Joe

15:05-15:48

You know what I found so interesting in reading your book, because you described the immune system so beautifully, the adaptive versus the innate immune system. But I begin to think about it a little as threading a needle or Goldilocks, not too hot, not too cold, because if your immune system isn’t up to snuff, you’re going to get sick.

But if it’s too active, you’re going to also get sick, you may have immune reactions. It’s like, how does it know just the right amount of reaction and not too much or too little?

Dr. Robynne Chutkan

15:49-17:48

Well, I’m so glad you mentioned that concept because I think that if you understand that concept, you probably understand 75% of immunology. And I think it’s so important that I just want to go over it a little bit more, and then we’ll talk about how to get the Goldilocks immune system.

So I like to divide it up just as you did, Joe. So overactive immune system versus underactive immune system. But I like to divide it further.

So think of that as there’s a line on a piece of paper and everything above that line is an overactive immune system and everything below that line is an underactive immune system. But I want you to draw another line in the paper, this one, a vertical line, not a horizontal line. And everything to the left of that line is internal threats in our body and everything to the right of the line is external threats.

So now we have four quadrants. But let’s start with the internal-external discussion. Internal threats with an overactive immune system. So you’re in that top left-hand quadrant of your grid now of the four boxes we’ve drawn. So overactive immune system, internal threats. We’re our body responding inappropriately, overreacting to our body’s own normal tissue. In the case of rheumatoid arthritis, it’s the joints. In the case of psoriasis and eczema, it’s the skin. In the case of Crohn’s and ulcerative colitis, it’s our gut bacteria.

So our body is mounting an abnormal high immune response to our own normal tissue. It’s treating our normal tissue as foreign, as a foreign invader and attacking it. And we have over 100 different autoimmune diseases now. One in four Americans, more than 50 million people. And many people have more than one because, of course, there’s sort of a common cause of these things.

So autoimmune diseases are sort of modern day diseases, if you will, and they really are a sign of dysregulation of the immune system. It’s an overactive immune system responding to internal threats.

Joe

17:48-17:58

Now, Dr. Chutkan, I’m going to ask you to hold that thought. We’re going to take a break, and when you come back, we’re going to talk about the under-reacting immune system.

Terry

17:59-18:07

You’re listening to Dr. Robynne Chutkan. She’s the author of “The Antiviral Gut: Tackling Pathogens from the Inside Out.”

Joe

18:08-18:14

After the break, we’ll find out more about what happens when the immune system is under- or over-active.

Terry

18:14-18:21

Too much and too little are both problems. How can we help our bodies get this just right, like Goldilocks?

Joe

18:21-18:27

We’ll also learn how a patient with Crohn’s disease tackled her condition with food.

Terry

18:39-18:42

You’re listening to The People’s Pharmacy with Joe and Terry Graedon.

Joe

18:51-18:54

Welcome back to The People’s Pharmacy. I’m Joe Graedon.

Terry

18:54-19:50

And I’m Terry Graedon. How can you fine-tune your immune system so that it neither runs too hot nor too cold? In other words, is there something you can do to find the sweet spot where you’re protected from pathogens but not suffering from autoimmune attacks?

Joe

19:50-20:22

We are talking with Dr. Robynne Chutkan. She’s a gastroenterologist and a faculty member at Georgetown University Hospital. Dr. Chutkan is the founder of the Digestive Center for Wellness, an integrative gastroenterology practice located in Washington, D.C.

Dr. Chutkan is the author of the digestive health books: “Gutbliss,” “The Microbiome Solution,” “The Bloat Cure,” and most recently, “The Antiviral Gut: Tackling Pathogens from the Inside Out.”

Terry

20:24-20:59

Dr. Chutkan, you’ve just described a graph in which we have a horizontal line and above the line, the immune system is overactive. Below the line, the immune system is underactive. And we have a vertical axis, which divides our immune system from internal threats to the left, external threats to the right.

We’ve just talked about the upper left quadrant in which we get autoimmune diseases because the immune system is overreacting to what it perceives as internal threats. So tell us about the other three quadrants, please.

Dr. Robynne Chutkan

21:00-29:17

What a beautiful summary. Thank you so much for that. So if we go to the other side of the overactive immune system, so now we’re talking about external threats. We’re talking about allergies, allergies to bees or wasps or seasonal allergies. And I think back to when I was in elementary school, there was one kid in my entire school who had a food allergy. Everybody knew him. He was kind of famous because he was allergic to peanuts and nobody else was allergic to anything. Now it’s rare to find a kid who isn’t allergic to something.

So we’ve seen this explosion of allergies. And again, that is a sign of immune dysregulation, dysregulated immune system overreacting, but to external threats in the environment, whether it’s an insect to food, et cetera. So now let’s travel down to the underactive immune system. And on the left side, internal threats, we’re talking about cancer, because our immune system doesn’t just protect us from infection and pathogens. It’s also our cancer surveillance system. It goes about our body and it weeds out cells that are starting to divide a little precariously where the genetic material is not being reproduced properly. Maybe it’s starting to develop a malignant cell line.

And a big job of our immune system, a big role is to weed out those cells and make sure they’re destroyed. So when you have an immune system that’s underactive, it means that that cancer surveillance isn’t happening and we’re at risk for cancer.

On the other side of the vertical axis for external threats, this is where we’re talking about infection, an immune system that is not strong enough to clear infection. So the really interesting thing here is that if we look at deaths during the COVID pandemic, we see that a large percentage of them weren’t really due to the virus itself, They were due to the immune response. People suffering from what we call ARDS, acute respiratory distress syndrome, where they had an overblown response to the virus.

The immune response was so active that it destroyed normal lung tissue in the process. And people ended up on ventilators. Tragically, people ended up dying. But again, as a result of the immune dysregulation, we saw other people who weren’t able to clear the virus. And we worried a lot about people on immune suppressive drugs like steroids and biologics because those drugs suppress the immune system.

The interesting thing is those people didn’t seem to do as badly. People who were immune suppressed and, you know, all of us in the medical community typically have patients who are on immunosuppressive medication. We worried about those patients, but they seemed to do okay. It was really the patients who had the overblown immune response who seemed to do worse.

So to get back to your really important question, how do we cultivate a Goldilocks immune system? It turns out, again, that these gut bacteria are essential. They’re a critical part of the response. So you want to maintain a healthy microbiome. How do you do that? Well, you make sure you’re not killing off your microbes with unnecessary antibiotics and other medications that are disruptive to the microbiome. You eat a high fiber diet because what are those healthy microbes like to eat? They like to eat plant fiber.

And you know, you don’t have to be a vegan, but you got to get those fruits, vegetables, whole grains, nuts, seeds, you want to get all of that in. And we know from a very important study in 2018 by the American Gut Project, a nonprofit doing wonderful microbiome research, their study in 2018 was the largest microbiome study done globally. They looked at over 10,000 people in more than 40 different countries. And they found that the most reliable predictor of a healthy microbiome was the number of different plants people ate, with the magic number being more than 30 per week.

And so when I say plants, not just vegetables or fruits, but also whole grains, legumes, beans, nuts, seeds, herbs, spices, you get credit for all of it. And so that really was one of the most potent indicators of a healthy microbiome.

So that’s something that, you know, people listening can do right away. You can start thinking about those 30 different plants. And it might sound daunting, but I like to take a bowl of oatmeal as an example and say, okay, let’s say you use some almond milk to make your oatmeal. That’s one. The oats, two. Walnuts, three. Pumpkin seeds, four. Raisins, five. Blueberries, six. Little maple syrup, seven. You get credit for that, too. I love to add a little shaved coconut, eight. Cinnamon, nine. You can get nine different plant foods in a bowl of oatmeal.

You can easily get another 10 in a salad. You can throw in your lettuce, tomato, cucumber, olives, cabbage, broccoli, chickpeas. Just start throwing it in. So if you try hard, you can get to 30 in a day, but 30 per week.

And one of the really important things about that concept is I have patients who are vegans but they’re only eating four or five different plants a week. They’re stuck in that same peas, carrot, broccoli, and sweet potato rotation. So variety is very important.

But when you increase your consumption of plant fiber, what happens is that you increase the amount of certain healthy bacteria in your gut. F. prausnitzii is one of those important species. It’s important because it is one of the main producers of short chain fatty acids, things like butyrate, sometimes called butyric acid, propionic acid, acetate, acetic acid. And what these short chain fatty acids do is they regulate the immune system. They help you get to that Goldilocks immune response. And they also keep the gut lining healthy. And they also feed the gut bacteria themselves that are producing them. So it’s this incredibly synergistic cycle of events.

And so patients come to see me and they want to know, what can I do to improve my gut immune connection? Is there a supplement? What should I do? What complicated steps do I need to take? And I remind them, you just need to eat more plants as the number one step that you need to do. And then you need to have a careful look in your medicine cabinet and think about medications you might be taking that could be harmful to either the microbiome or the gut lining or stomach acid.

So are you taking non-steroidal anti-inflammatory drugs that are making little holes in your gut lining? Are you taking not just antibiotics, but any of the list of more than 42 different classes of medications that have been shown to be disruptive to the microbiome?

Antidepressants, artificial sweeteners, laxatives, there are many of them. So you’ve got to be judicious about what you’re taking from a medication point of view. And then the other thing I like to remind people is where do we get our microbes from? Well, after we’re born and we get them from our mothers, particularly those of us who are lucky enough to be born coming out through the birth canal rather than a C-section, after that, we get them from our environment. We get them from soil.

So exposure to nature is a really, really important way for us to replenish our microbes and have a healthy microbiome. So that refers to us being out in nature as well as eating food that’s grown in nature, not food that’s grown in a warehouse somewhere, not the sort of industrial organic food.

So the steps to have a Goldilocks immune system are fairly straightforward. And then there are some other add-ons that are important too, like sleep, because we know sleep reboots the immune system like a computer and that it’s really essential.

We have a very important study from the British Medical Journal that showed that people who were chronically sleep deprived had an 88% increase in risk of COVID. So sleep is essential. We know that controlling stress is important. We see stress as a risk factor for morbidity and mortality with this pandemic. So there are other things too that are maybe not directly related to the gut, but that are really important for keeping it all humming along and functioning well.

Terry

29:17-29:42

And of course, getting out in nature might help you control your stress. I do want to ask about medications. You said you need to pay attention to what’s in your medicine cabinet. And I want to ask you about a patient that you treated early in your career, a woman with severe Crohn’s disease.

She came to you and you prescribed medications because that’s what you would learn to do. Can you tell us what happened?

Dr. Robynne Chutkan

29:43-36:47

Yes, yes. I remember her so well. And gosh, it’s so great that you’re bringing up her story. So I was a young gastroenterologist just in my first or second year on faculty at Georgetown. And as you said, doing what I was trained to do, which is to prescribe medication.

She was around my age, and she actually worked at the hospital in the radiology department. And she left, she moved to New Jersey for a couple years. And then she decided to come back. She came back to the Washington area. And she came to see me. And as you said, she’d had Crohn’s disease and quite severe Crohn’s disease. And I had been up close and personal with her Crohn’s disease doing her colonoscopy several times in the past.

So she came to see me in the clinic. And I remember we caught up. And I asked her, okay, ‘So tell me, you know, what are you on?’ And I got out my pen, because at that time, we didn’t have an electronic medical record, got out my pen to write a note. And she said, ‘Nothing.’ And I remember I froze. I was like, ‘What do you mean, nothing?’ And she said, ‘I’m not taking anything.’ And I gave her my little spiel about, oh, that’s like driving a car with no insurance. You know, things could go terribly wrong.

And I was literally frightened for her because the idea that you could treat or control a serious autoimmune disease like Crohn’s without medication was just, I mean, that was frightening. It was a frightening idea to me.

And she told me what she was doing. And at the time, you know, the diet didn’t necessarily have a formal name, but it was a variation of a diet called the Specific Carbohydrate Diet, which is a low complex carb diet, but not a low carb diet specifically, but it takes out a lot of the processed carbohydrates, like, you know, the baked goods and so on. The dairy other than on that diet, people can make their own yogurt, but takes out the processed dairy and the refined sugars and a lot of the processed grains. And she was having great results with it clinically.

So I said to myself, okay, well, she’s feeling good, but that’s probably placebo effect. Let’s see what’s really going on in her colon. And I did her colonoscopy a few weeks later, and it was normal. Her severe ulceration from her Crohn’s disease had healed completely, completely.

I mean, I remember thinking, this is magic. Like, how can this be? And I think back now, you know, 25 years later, and I think, no, it’s magic the other way. It’s magic to not consider the role of what we eat and how we feel and specifically on what’s going on in our guts. But I had been so trained and indoctrinated, quite frankly, to think that medication was the only path.

And to be clear, the medications are fabulous. I’m glad we have them. We’re in an era of really effective medications for these diseases, but here’s a problem: when you treat a disease that is an overactive immune system, like Crohn’s, it’s an autoimmune disease, you treat it by suppressing the immune system.

So now you’re down in that, below that horizontal line. And now you’re at risk for cancer and infection. And that is indeed exactly the risk factors of these medications. They all carry the risk of serious infection, viral, bacterial, fungal, et cetera, as well as cancer. And autoimmune diseases affect a wide range of people, but the ones I treat primarily, Crohn’s and ulcerative colitis, affect young people.

And so we’re talking about putting people in their teens and early 20s and 30s on medications for life that have these potentially very deleterious side effects. So this patient was the first person who really opened my eyes to what was possible and sort of, you know, began my journey to see how we could treat these diseases with a food as medicine approach.

And I’ll tell you, I saw a young man yesterday in my office, a new patient with ulcerative colitis, really lovely young man. And his mother was with him. He’s in law school. And he had been on these drugs for a long time. And he said, ‘You know, the drugs really helped me, particularly in high school when I was diagnosed. I just wanted to be a kid and, you know, do what the other kids were doing. And I didn’t want to be having 20 bloody bowel movements a day and, you know, having accidents.’ So he said, ‘I was very grateful to the drugs.’ He was on Remicade initially, infliximab, one of the first monoclonal antibody biologic drugs that we had for inflammatory bowel disease.

So he said he was very grateful. But what he has noticed over the last decade is that he’s just not well. He’s sick all the time. I mean, yes, his colitis has improved a lot, but he’s sickly. He has colds, his skin, he’s gotten really bad acne. He’s sick all the time. He had COVID twice, serious episodes both times.

And so he can feel that his immune system is suppressed, where he’s sort of half-masked. And one of the things, it’s really important to make sure people are good candidates for a food as medicine approach. Some people, quite frankly, are just too sick. There are many patients who I say, you know, you actually would probably benefit from going on a bigger gun medication like a biologic to get your disease inactive enough to a point where we can treat it nutritionally.

Or sometimes people have strictures. If you have Crohn’s, you can have narrowing in the intestine. And so it’s a mechanical narrowing. And I explain, you know, no amount of kale is going to open this back up. You probably need to have this addressed surgically. And then we can really think about nutritional therapy to prevent recurrence. So just as we need to be judicious with our pharmaceuticals, we need to be judicious and realistic about what food can do.

Food can do a lot, but it is also not magic. And in this particular case with this young man, he was a great candidate. He was already a pretty good eater. He was very committed to making some changes to his diet. And his disease at this point was just at the bottom part of the colon and not in terrible shape. So he’s a really good candidate. And I’m so excited to be working with him to see if we can get him off the biologic.

But I never want people to feel like there’s a wrong or right path. There’s a path that’s right for them. And if you’re at the point in your life where you sort of, you know, you just need the quick fix to get this taken care of, you can’t maybe make that commitment to diet and lifestyle, that’s not wrong.

But it is also important for people to know that there are other paths out there for treating these diseases without the immunosuppression. We have other medications for autoimmune diseases that don’t suppress the immune system. They tend to be not as efficacious, but sometimes using one of those medications with the diet and lifestyle can really get people where they need to go.

So I always want people to know there are lots of options out there. We have a lot of tools in our toolbox and trying to find the right tool for people and particularly the tools where the side effects aren’t worse than the actual disease. That’s important.

Terry

36:47-37:01

You’re listening to Dr. Robynne Chutkan. She’s a gastroenterologist and a faculty member at Georgetown University Hospital. Her most recent book is “The Antiviral Gut: Tackling Pathogens from the Inside Out.”

Joe

37:01-37:09

After the break, we’ll find out  why the mucin lining your digestive tract is critical in protecting you from viruses.

Terry

37:09-37:16

How do microbes interact with mucus? And how do medications affect our digestive lining?

Joe

37:16-37:30

When the gastrointestinal tract loses integrity, the leaky gut that results can have serious consequences. Dr. Chutkan shares her plan for supporting an antiviral gut. She also tells us about some of her favorite foods to help.

Terry

37:39-37:55

You’re listening to The People’s Pharmacy with Joe and Terry Graedon. Welcome back to The People’s Pharmacy. I’m Terry Graedon.

Joe

37:55-38:17

And I’m Joe Graedon.

Joe

38:31-38:46

Today, we are talking about supporting your digestive tract so that it can protect you from invading pathogens. The lining of your digestive tract is especially important, but we don’t often think about it. What should we be doing differently?

Terry

38:46-39:16

For answers, we’re talking with Dr. Robynne Chutkan, a board-certified gastroenterologist. She’s a faculty member at Georgetown University Hospital and is the founder of the Digestive Center for Wellness, an integrative gastroenterology practice in Washington, D.C.

Dr. Chutkan is the author of the digestive health books, “Gutbliss,” “The Microbiome Solution,” “The Bloat Cure,” and “The Antiviral Gut: Tackling Pathogens From the Inside Out.”

Joe

39:18-40:48

Dr. Chutkan, you’ve just been explaining the benefits and risks of some of the most popular pharmaceuticals in the pharmacy. I mean, we’re talking about billion-dollar drugs, Enbrel, Humira, these biologics, and they do work very well, but they do have an impact on the immune system. And so we hear on those commercials things like lymphoma, and we hear about other infections, and watch out for tuberculosis.

And so I guess they’re double-edged swords, as are so many of the medications that we rely on on a daily basis, like the NSAIDs, ibuprofen, naproxen that people take for their aches and pains. But I’ve got a different question for you. When I was in graduate school, the head of the physiology department at the University of Michigan was a famous researcher by the name of Davenport. And he was particularly interested in the gastrointestinal system.

And I remember he was really focused on mucus. And he asked us, as pharmacology graduate students, well, why doesn’t the stomach digest itself? It’s like battery acid. It’s so powerful. And there it is just sitting in your stomach and it’s not doing any damage. It’s all about mucus and the mucin lining. It is all about mucus. Tell us about it.

Dr. Robynne Chutkan

40:50-45:17

Mucus is like a cross between jello and glue. And it’s this sticky polymer. And people think of mucus, first of all, as coming from the lungs. But the reality is most of the mucus in our body is made in our GI tract, about one and a half liters a day.

And mucus serves a couple functions. One of them is just as a lubricant. So it lines all those organs that are in contact with the environment, our mouth, our nose, our upper, our oropharynx, if you will, our mouth and airway, our reproductive organs like the vagina, even the inside the urethra, and of course, the GI tract. So it helps to lubricate things. And in the case of the GI tract, it helps to lubricate the gut so that the products of digestion can move smoothly from north to south.

But it also has another purpose. One purpose is a barrier. So between the microbes that are floating around in the gut and the gut lining is a thick layer of mucus. And so that helps to protect the gut lining. And the other is that mucus has enzymes in it that can actually degrade viruses that get in.

So mucus traps viruses like SARS-CoV-2 in its sticky matrix. And then it has enzymes that will degrade and sort of dissolve the virus. And then, of course, you have those cilia, those finger-like projections in the lungs that can move the virus up and out. And if you swallow it, ideally stomach acid works on it some more.

So you see how this is all designed to work together. So it’s like your body’s internal flypaper that catches these viruses. And, you know, there’s this, when we think about this concept of super spreaders, we know that super spreader events aren’t explained by differences in the virus. They’re not based on viral behavior. You can have a large gathering where few people, if any, get a virus, or you can have a small event where everybody gets it.

And of course, there are things like how close you’re in contact with people, whether you’re indoors or outdoors. But it turns out that when some people sneeze on you and transmit a virus versus somebody else who’s infected sneezes on you and doesn’t, it has to do with the mucus of the person who’s sneezing on you. Because if you have somebody whose mucus is very potent and it has trapped the virus and the mucins, the proteins in their mucus, have killed the virus, they’re going to sneeze on you and they’re going to transmit dead virus and you’re not going to get infected.

But if somebody sneezes on you whose mucus is a little less potent and the mucins in their [mucus] may not have done as good a job as trapping and killing the virus, they are going to infect you.

And what’s really interesting is that we, in addition, so the mucus can physically trap viral invaders. It has enzymes that degrade viral proteins and it has antibodies that can neutralize them. And mucins in saliva and breast milk also have antiviral activity that can inhibit even potent viruses like HIV.

So again, you know, the quality of these host defenses is really important. And so when we think about something like mucus, we know that people who smoke, for example, have mucus that is much, much less potent in terms of its ability to protect us from pathogens. Being dehydrated would also affect your mucus.

And so, again, there are, you know, there are some genetic factors with all of these things that many of these things are things that we can improve ourselves. We can drink more water. We can stop smoking. These are really important things. And along the line of mucus and pharmaceuticals, we know that cough syrups and these cough suppressants are really problematic because they prevent you from being able to expel these pathogens.

We want to produce mucus and we want to cough it up so we can get rid of the pathogens. And so when you take these different cough syrups that suppress your cough reflex and or things like antihistamines that can dry you out and decrease your mucus production, you’re really sabotaging your host defenses.

Terry

45:17-45:33

So Dr. Chutkan, if most of the mucus is actually in your digestive tract, it’s in there interacting with all the microbes in your digestive tract. What’s the impact of the microbes?

Dr. Robynne Chutkan

45:33-47:23

Well, the microbes have to, you know, we don’t want those microbes to penetrate through the gut lining. They’re in the gut lumen for a reason. That’s where we want to keep them. And so it provides, you know, the intestinal epithelial barrier is only one cell thick.

So the mucus really buffs up that barrier and provides an additional zone of protection. Because when we look at, for example, there was a study, a microbiome study done at University of Massachusetts in 2021. And that study found that the most important predictor of outcome from COVID was actually the composition of the microbiome.

They found high levels of a bacteria called Enterococcus faecalis was associated with worse outcomes and death. And high levels, conversely, of the bacteria referred to earlier, Faecalibacterium prausnitzii was associated with good outcomes. Enterococcus faecalis is a bacteria that is also associated with post-op infections, and it can penetrate the gut lining and get into the body and get into the bloodstream and cause problems.

So that protective barrier that mucus provides, I have an analogy in the book that I’ll share with you. It’s 5,000 times the diameter of a viral particle like SARS-CoV-2. So the analogy is a human wading through 150 gel-filled football fields to reach the end zone and score a touchdown.

So it creates that buffer so that bacteria like Enterococcus faecalis have a difficult time penetrating that intestinal epithelial barrier, that gut lining. So it’s so beautifully and cleverly designed. And the main thing we have to do is not mess it up.

Terry

47:24-47:38

And if we do mess it up somehow, then we run into problems with what the gastroenterologists like to call intestinal permeability and what the rest of us call leaky gut, right?

Dr. Robynne Chutkan

47:39-48:36

That’s right. That’s right. And one of the most important points I want to make to people is that these are not things that you fix by taking a supplement. These are things that you primarily fix by not taking things. You know, people want a pharmaceutical fix, whether that’s a prescription, over-the-counter, or a supplement. But these are things that are mostly created as a result of too many of these pharmaceuticals, whether a prescription, over-the-counter, or supplement.

So rather than, you know, telling people or people want advice about what probiotic, what supplement, I get them to bring all their pharmaceuticals and lay them out on my office table. And then I pull out my rubbish bin and one by one, I usually drop them in and explain, you know, why they shouldn’t be taking this. And of course, particularly for a prescription drug, this needs to be done in concert with your healthcare provider. Please don’t just start getting rid of, you know, putting medications in the rubbish bin without checking with your physician.

Joe

48:37-49:15

Dr. Chutkan, and a lot of people like to, dare I say it, play doctor by going to the pharmacy and buying over-the-counter medications. And now, of course, NSAIDs, non-steroidal anti-inflammatory drugs, are incredibly popular because everybody seems to have an ache or a pain or a fever or a headache. And so they’re taking Aleve. They’re taking Advil. They’re taking ibuprofen over the counter generically or naproxen. And then their doctors are prescribing these. So tens of millions of people are taking these drugs on a daily basis. And they’re affecting intestinal permeability.

Dr. Robynne Chutkan

49:16-50:57

Yeah, they are. It’s not just the NSAIDs. It’s also you think about the antipyretics. So the things we take for fever, which would be NSAIDs, but also Tylenol. It turns out fever is one of our body’s most important host defenses. So if we look at poliovirus, poliovirus replicates 250 times faster at normal body temperature compared to when we have a fever.

So a fever is our body’s way of trying to slow down viral replication, trying to keep us safe. But what do we do? We suppress a fever. And so, you know, the pediatric guidelines for a while now have talked about, you know, not using cough suppressants, not using antipyretics, fever medication, but we still intrinsically reach for them.

And we reach for them because we don’t understand the feedback our body’s giving us. So we confuse a physiological response like a fever. We think it’s an illness. We confuse a physiological response like a hangover, a physiological response like reflux. Reflux is our body’s way of telling us you have overfilled your stomach, you have eaten too late, you have eaten too much fatty food, whatever it is. And that’s why this stuff is coming up. And I’m giving you feedback.

And so again, we’ve got to understand the feedback our body’s trying to give us and not just suppress all these symptoms with pharmaceuticals without understanding the messages, the important information that’s contained in them. I mean, I said to a friend the other day, imagine if people didn’t get a hangover, how many people would die from alcohol poisoning because they just keep drinking.

Terry

50:57-50:58

Right.

Dr. Robynne Chutkan

50:58-51:07

And they wouldn’t get that terrible, you know, headache and you feel horrible and you’re like, oh, oh, that’s what happens when I do that. Maybe I should do less of that.

Terry

51:07-51:24

Not do that in the future. Dr. Chutkan, we have just a few minutes and I’m hoping that you’ll walk us through, briskly, your plan for an antiviral gut to protect us from infections.

Dr. Robynne Chutkan

51:26-53:34

Absolutely. The difference with this book, and I’m proud of all of them, all four of them, but the difference with this book is that the plan is really a little over half the book because I wanted to be sure to give people the information, the practical steps, not just to say here’s what can go wrong, but to tell them here’s what you can do about it.

So the plan is really divided into several chapters, the antiviral gut plan, and I consider sort of “strengthening-from-within” plan. So in the first chapter of the plan is called Securing Defenses. And it talks about how you can optimize your body’s innate capacity to neutralize viruses with stomach acid, to trap with mucus, to burn with fever, to wall off viruses with your gut lining, while simultaneously improving your reflux, your digestion, your overall gut health.

The second chapter in the plan is called Mastering Your Mind. And that really focuses on stress and sleep and what you can do to improve those things, improve your sleep hygiene, improve your stress response so that you can be more resilient. The next chapter is Changing Your Environment.

And I talk about the Japanese practice of shinrin yoku or forest bathing and how that can reduce stress hormone production, enhance your immune system, and what we touched on earlier, the importance of exposure to soil microbes.

Chapter 12 in the plan is being Thoughtful About Therapeutics. So I go through each of the classes of medications that is sort of a threat to your gut health, I talk about potential alternatives, and I give people questions to ask their doctor. So I literally have the list of questions. You know, if you’re on this drug, here are the five questions you should ask your doctor, here are four or five alternatives.

And then chapter 13 is a plan at a glance. It’s putting it all together with a kind of snapshot glance at what your daily antiviral gut routine would look like. And then the last section is recipes with some really simple, delicious food. Nothing in there is difficult to make and it’s all really quite delicious. So that’s a plan in a nutshell.

Joe

53:35-53:49

In the minute we have left, Dr. Chutkan, some of your favorite foods. If we were to go out to lunch with you today, if we were to have dinner with you on Saturday night, what would be on the menu?

Dr. Robynne Chutkan

53:50-54:14

I, you know, beans and greens are two of the things I really focus on. So, and I have to admit that my husband is a lentil maker in the house. So he makes delicious curry lentils and there’s lots of onion and garlic and different spices and curry and coconut milk would be lentils, curry lentils, some brown rice, and I would probably do some sauteed spinach with that.

Terry

54:14-54:18

You’re already getting halfway to your 30 plants a week.

Dr. Robynne Chutkan

54:18-54:31

Yeah, and exactly. So with the lentils, again, there’s ginger and onion and garlic and leeks and curry powder and bay leaves. So there’s probably six or seven different plants in there along with the lentils.

Terry

54:31-54:39

It sounds nutritious as well as delicious. Dr. Robynne Chutkan, thank you so much for talking with us on The People’s Pharmacy today.

Dr. Robynne Chutkan

54:40-54:46

Always such a pleasure to be with you on The People’s Pharmacy. I love the work you do. Wonderful to be a part of this.

Terry

54:47-55:14

You’ve been listening to gastroenterologist Robynne Chutkan. She’s a faculty member at Georgetown University Hospital and is the founder of the Digestive Center for Wellness, an integrative gastroenterology practice in Washington, D.C.

Dr. Chutkan is the author of the Digestive Health books, Gutbliss, The Microbiome Solution, The Bloat Cure, and “The Antiviral Gut: Tackling Pathogens from the Inside Out.”

Joe

55:15-55:23

Lyn Siegel produced today’s show. Al Wodarski engineered. Dave Graedon edits our interviews. B.J. Leiderman composed our theme music.

Terry

55:23-55:30

This show is a co-production of North Carolina Public Radio, WUNC, with The People’s Pharmacy.

Joe

56:09-56:19

Today’s show is number 1,336. You can find it online at peoplespharmacy.com. That’s where you can share your comments.

Terry

56:20-56:26

Our interviews are available through your favorite podcast provider. You’ll find the show on our website on Monday morning.

Joe

56:27-56:48

At peoplespharmacy.com, you can sign up for our free online newsletter to get the latest news about important health stories. By subscribing to our newsletter, you will also have regular access to our weekly podcast and find out ahead of time which topics we’ll be covering. In Durham, North Carolina, I’m Joe Graedon.

Terry

56:48-57:28

And I’m Terry Graedon. Thank you for listening. Please join us again next week. Thank you for listening to the People’s Pharmacy Podcast. It’s an honor and a pleasure to bring you our award-winning program week in and week out. But producing and distributing this show as a free podcast takes time and costs money.

Joe

57:29-57:38

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Terry

57:39-57:43

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Joe

57:44-57:57

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