Do I Need to Take Probiotics? with Dr. Daniel Freedberg

Faith: Welcome to Health Matters, your weekly dose of the latest in health and wellness from NewYork-Presbyterian. I’m Faith Salie.

Trillions of microbes live in and around us, with many thriving in our gut microbiome. These microbes are important to our health. So how do we keep the gut microbiome healthy? To answer questions on everything from probiotics to the importance of fiber, I talked with Dr. Daniel Freedberg, a gastroenterologist at NewYork-Presbyterian and Columbia. 

He joined me to clear up some common misunderstandings about what’s going on in our gut, how the microbes we need got there in the first place, and what we can do to keep them happy, so we stay healthy. 

Faith: Dr. Daniel Freedberg, thank you so much for joining us today.

Dr. Freedberg: My pleasure. Glad to be here.

Faith: We’re here today to talk with you about the mysterious world of the gut microbiome. These days people seem really invested in gut health and we hear about probiotics and prebiotics. So I am excited to get a deeper understanding of all of that. So to start: let’s make sure we all know what exactly constitutes the gut.

Dr. Freedberg: In the medical sense, the gut is everything between your mouth and your anus.

Faith: Esophagus, stomach, large and small intestines, right?

Dr. Freedberg: You got it. Yep. That’s it.

Faith: OK. All right. So what is the gut microbiome? What does that mean in your work?

Dr. Freedberg: The gut microbiome is all of the stuff, all of the bacteria that live in that whole big, big area and all of the stuff that they make; and the stuff that we eat that they may eat. So it’s the fiber that we eat, it’s the chemicals that the gut bacteria make, and it’s the gut bacteria themselves. Now when most people talk about the gut microbiome, really what they are talking about is the colon is where the bulk of these organisms are. The colon is big, uh, physically large. It’s larger than these other areas. And there’s many, many more bacteria, more things that the bacteria make, more things that the bacteria eat in the colon compared to the stomach or the esophagus, which are relatively sterile.

Faith: There’s a lot of good bacteria, right? I think, I think we’re here to celebrate it today.

Dr. Freedberg: Absolutely. One thing that the gut does generally is it, and this too kind of blows my mind. When you’re eating, essentially, you’re, you’re taking things, you’re putting them into your gut and your body needs to be able to take out the good parts of those things you’re eating and put it into your blood and then not put other parts of it into your blood. And the bacteria are actually helping in that selection process, that your body is able to sense what’s inside it, take out the nutrients and the good stuff, and not take out the bad stuff. And the bacteria are crucial in helping us do this.

Faith: What does a healthy gut microbiome look like?

Dr. Freedberg: There is no single sort of the best or the healthiest microbiome. However, there are still some generalities we can say about what constitutes a good or a healthy microbiome. And one of the things is definitely diversity. So diversity, meaning having a lot of different kinds of bacteria seems to be really important. If you look at microbiomes that are not diverse, they’re usually more associated with the diseased state than with the healthy state.

Faith: Where do these microbes come from?

Dr. Freedberg: Well, it’s, it’s there in our gut. It’s on our foods. It’s on our skin. Microbes are everywhere. If you culture bacteria off your desk surface right now, your desk is teeming with bacteria. Every surface in your home is teeming with bacteria. And most of these bacteria, they are fecal bacteria. So these are the same bacteria that, I’m sorry, but they are.

Faith: You did not give everyone a warning for that!

Dr. Freedberg: Our world is covered in what people in this field call a fecal veneer. That small, small amounts of fecal bacteria are everywhere.

Faith: Dr. Freedberg, you buried the lede. 

Dr. Freedberg: A fecal veneer, that’s correct, yes.

Faith: OK.   

Dr. Freedberg: The fecal bacteria are the most numerous kind of bacteria. These are organisms like E. coli, Enterococcus…There’s a war taking place in your gut right now. Every day, the bacteria are dying by the thousand and being born again in huge numbers. 

Faith: And what can we do to nourish our gut microbiome and, and keep it healthy? Are there particular foods we should eat or avoid?

Dr. Freedberg: Fiber is good, because much fiber is prebiotic, meaning that it nourishes the gut bacteria, it encourages the growth of more different kinds of gut bacteria, and especially gut bacteria that don’t cause disease, meaning they don’t cause bloodstream infections and things like that. Uh, and they probably produce good small molecules, things like short chain fatty acids, other uh, small molecules that have various benefits in the human body. And the studies show this again and again, that if you put someone on a high fiber diet, you see this huge shift in their gut bacteria, within a day.

Faith: Oh my gosh, that is, that is so, actually so inspiring for people who want to know, like, how long does it take to make a good change? 

Dr. Freedberg: Very quickly. In fact, they’ve done other sort of interesting microbiome studies showing that if you change your environment, you know, you, you move to a new apartment or you get a new roommate that also changes your gut bacteria. You start sharing your gut bacteria with that new roommate. If you get a pet, you share your gut bacteria with the pet. 

Faith:  So, let’s get into probiotics: how helpful are probiotic supplements and when are they recommended? 

Dr. Freedberg: They may not be, be beneficial. The American Gastroenterologic Association, the AGA, has just three categories that it recommends probiotics for, and even those recommendations are very weak. They’re conditional recommendations in the terminology of the AGA. Those three conditions are, uh, something called pouchitis, which is a condition when your colon is taken out and you just have a, you have a pouch. People who have, uh, Crohn’s disease could have this. Um, so some people do have it, but probably most of the listeners don’t. They recommend it for, preterm infants to prevent something called necrotizing enterocolitis, which can be a very, uh, very serious problem, and, uh, they recommended for prevention of antibiotic associated diarrhea, especially prevention of a condition called C. diff. that is a kind of a poster child of the microbiome diseases. And those are the three, those are the only three conditions that they recommended it for because evidence for anything else really has not been great and  there are now quite a few trials that have shown no benefit, when, uh, probiotics are compared to placebo.

Faith: I think that’s surprising to a lot of people who thought they were just being, you know, healthy by taking probiotics.

Dr. Freedberg: Yeah, I think a lot of people take probiotics for general health and if they feel better on their probiotic, uh, OK, fine. Um, some probiotics are very expensive. They’re not medicines, so they don’t need to prove that they have health benefits. They also don’t have super rigorous criteria in terms of what they contain, meaning that some of these bacteria may be difficult to package without killing the bacteria, and so they may not be alive still by the time the person takes them.

Faith: So, in other words, they are not a necessary part of everyone’s supplement regime.

Dr. Freedberg: You don’t need to take a probiotic. You can be healthy without it. 

Faith: What about fermented foods like yogurt and kimchi? Is it helpful for our gut to be eating and, and drinking these fermented foods? 

Dr. Freedberg: The fermented foods do contain the bacteria that we usually think of as good. Uh, things like lactobacillus. We don’t know exactly what they may be doing for us that’s good. There probably aren’t that many disease categories where they’ve been proven to be good. That said, they seem to make the small molecules that we think are beneficial. And they don’t cause disease. So, yeah, they’re probably good, just like fiber.

Faith: As a doctor, are there any foods that you strongly recommend to keep our guts very healthy?

Dr. Freedberg: I don’t tend to push very specific diets because I don’t think the data is there to suggest that that’s really going to be what makes a difference in people’s health. Um, sometimes also I meet people who are on these very restrictive diets and I worry that it can actually be harmful; that it creates anxiety. It diminishes rather than increases their quality of life. 

Faith: You mentioned prebiotics being in fiber. What, what are prebiotics and why are they so good for us?

Dr. Freedberg: Prebiotic fiber, it’s not the bacteria itself, but it’s going to change the bacteria and that, that is another thing I like about fiber. It does change the gut microbiota quite profoundly. And when people take probiotics, I think their goal is to change their gut bacteria. So sometimes I try to redirect them towards that overall goal by saying, if you wanted to change the ecology of a region, you wouldn’t just go on putting in like a bunch of little plants. You would change the soil conditions generally.  And in a sense prebiotic fiber is doing that. You’re changing the conditions of the microbiome as a whole to encourage different bacteria to grow.

Faith: What are some of the ways that our gut flora can get out of whack?

Dr. Freedberg: The worst is antibiotics and antibiotics are unquestionably bad for your microbiome. Now, I’m not trying to slam antibiotics. Antibiotics are life saving. They’re one of the best interventions we have in medicine when they’re used appropriately. But oftentimes, antibiotics could be avoided. They’re given for a viral condition where they’re not gonna make the symptoms any better. Um, or they are necessary, but they could be given at a lower strength or for fewer days. And less is more with antibiotics because they are bad for your gut bacteria. They kill the good bacteria and they breed resistance. They’re still one of the best things we’ve got. So that’s the challenge. 

Faith: So if someone wants to check on the health status of, of their gut microbiome, um, what should they do?

Dr. Freedberg: I probably focus on their symptoms. Are they eating well? Do they have diarrhea? Do they have constipation? Do they have abdominal discomfort? If they don’t have these symptoms and they feel well, then they’re probably doing OK. If they have these symptoms, things that are bothering them, things that are interfering with their daily life, I focus on the symptoms themselves and there are good medicines for some of those symptoms, some of which may also impact the gut bacteria or which may work in part via their impact on the gut bacteria.

Faith: Dr. Daniel Freedberg, I have learned so much today about my gut and gut health. Thank you so much for joining us!

Dr. Freedberg: Thank you for having me.

Faith: Our many thanks to Dr. Daniel Freedberg. I’m Faith Salie. 

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