What’s up with our gut? A Mayo Clinic gastroenterologist has answers

CATHY WURZER: I know you've been on the internet, and I know you've probably seen that gut health is all the rage. There are tons of prebiotics, probiotics, and gut health drinks that can claim to help with everything from puffy faces to mental health. There's even been ads recently to revitalize your gut in 2024. But we're wondering how to separate fact from fiction and whether our gut microbiomes actually need this much help.

Joining us right now is a leading gut microbiome researcher and gastroenterologist at Mayo Clinic in Rochester. Dr. Purna Kashyap. Doctor, welcome.

DR. PURNA KASHYAP: Thank you. Thanks for having me.

CATHY WURZER: We should be clear on what we're talking about here. What is the microbiome?

DR. PURNA KASHYAP: The microbiome is a collection of microbes, which are present in different locations in our body, the majority or the most diverse set being in the intestines or the gut, which is what we refer to as the gut microbiome. And they're essentially an extension of our own genetic makeup, because the genes that these microbes have encode enzymes and allow us to digest some of the foods that we normally cannot digest by ourselves.

CATHY WURZER: So we'll focus our attention here on the gut microbiome. What can the microbiome reveal about our health?

DR. PURNA KASHYAP: The microbiome is really an overall reflection of who we are. I've always believed healthy people have healthy gut microbiome, but they're often a reflection of what we eat, where we live, what our lifestyle is, as all of these factors can dictate what kind of microbes are present in our gut.

CATHY WURZER: How do the gut microbiomes affect other parts of the body? I'm thinking joints, the liver, immune system.

DR. PURNA KASHYAP: So the gut microbiome is really present there to help us, because we provide it with nutrition. So the majority of the times it's doing things, which is maintaining the health of our intestine and overall our health, but it can produce things, just like I mentioned, they have genes, which break down food products which we eat into compounds, which can then get absorbed into the bloodstream. And they can travel away from the intestine and they can affect distant parts like our joints or the brain, or other parts of the body.

CATHY WURZER: Interesting. So can an imbalance in the microbiome lead to say autoimmune diseases? Or do we not know that at this point?

DR. PURNA KASHYAP: We do think that the microbes contribute to autoimmune diseases. And one thing to keep in mind is that these are complex diseases, which have multiple different things going wrong at the same time. So we can't pinpoint and say, this is it and we found the cause for autoimmune diseases. I think it's a combination of things of which microbiome is one of them.

CATHY WURZER: I'm wondering, this is a fairly new field, what do you think about the explosion of gut health drinks and that kind of thing and information on the internet?

DR. PURNA KASHYAP: Well, I mean, I definitely welcome the attention to gut health, because I think that is an important part of our body. And it makes an important-- It's important for our overall health, but I think the attention is misplaced, because it's more commercially driven and it's often putting the cart in front of the horse. I mean, like you said, it's a recent science.

We're still learning about the microbiome. We think it plays an important role, both in maintaining our health and in driving disease states, a lot of them which you mentioned previously. But we don't know enough that we can start treating this with probiotics or prebiotics. In fact, I think it was opportune because they were already there before the microbiome science took off.

So oftentimes, it's just putting two and two together and trying to say, we can just treat it. But I don't think it's that simple. I think we need some patience and we have to wait for the science to catch up before we start developing treatments to improve gut health.

CATHY WURZER: I'm sure then that you look probably skeptically at some of the tests available to tell if you have a healthy microbiome. I know you've probably seen those tests.

DR. PURNA KASHYAP: Yeah, because we really don't have a definition for healthy microbiome. We can't pinpoint and say this is a healthy microbiome. Like you just mentioned, each individual havors a set of microbes, which really define them based on what they eat and where they live. And so that is their healthy microbiome. The tests really are against-- similar to what I mentioned, is putting the cart before the horse.

I think they will be useful in the future, once we figure out what we're looking for. Right now, they're just there and we can't act on them. I think, if we were to follow an individual and we see start seeing a change in that individual's microbiome, that might be an indication or a sign that they might be moving into a disease category. We don't know that yet. So till we know that, I don't think these tests are useful.

And that's why you'll see none of these are really endorsed by any of the regulatory agencies. So I think we should really be wary of these tests.

CATHY WURZER: Do you recommend, though-- you can feed your microbiome in a sense, right? That's what I've heard anyway. Do you just try to eat healthfully and just call it a day in that respect? Or do you-- even yourself, do you take any probiotic? Is that worth anything at all?

DR. PURNA KASHYAP: So, you know, probiotics are tricky, because they're part of a lot of people's culture to start with. I grew up eating yogurt with every meal. And you know, I still continue to do that, but I don't do that thinking that I'm having a probiotic. It's a part of our culture. And similarly people eat sauerkraut or kimchi. And these are cultural foods, fermented foods, which contain microbes and they generally were considered good for our health.

But taking it as a way to improve your health, there's not data around that. So we can't say that should do it. Like you mentioned, what you eat is what your microbes will eat. So if you eat junk, they will really not get much to eat and they're not going to be happy. And if they're not happy, they will respond to that. If you're eating a balanced diet, which is a mix of fruits and vegetables and has dietery fiber and has a variety of food, that gives a lot of options for the bacteria and it allows a diverse range of bacteria to flourish in your gut, which makes it much less likely that you can damage it easily. So you're right. If you eat a healthy balanced diet, that will keep your microbes happy.

CATHY WURZER: Just curious, do unhappy microbes-- how do they act? How would you know perhaps that you have some unhealthy microbes in your gut?

DR. PURNA KASHYAP: You know, I mean, what we think is if you starve the bacteria, so if you're eating things like just simple sugars, which our intestines are very good at absorbing, then there is not a whole lot left to go down to the lower parts of the intestine, where the majority of the bacteria are still waiting for the food to show up. And if they don't get that food, then they'll start feeding on the lining of our intestine, which has mucus along it.

And this mucus has a lot of nutrients. And it's a barrier. It prevents bacteria from passing that barrier into, unless they have nothing to eat and then they'll start feeding on that mucus layer and depleting it little by little. There is no way for you to tell, because you won't feel any different till a lot of that may be damaged.

And that's where we think there might be ways by which bacteria can then start exerting harmful effects, because now the bacterial products can much more easily go across the intestine and get absorbed and drive a lot of health problems across the body. So that's why we recommend eating a healthy balanced diet.

CATHY WURZER: That makes sense. And if you start eating healthfully, some of us are trying to do that, can you, in a sense, heal some of that damage?

DR. PURNA KASHYAP: Yes. I think, to some extent, we think that we can restore the damage. It's not going to be instantaneous. We're in the Amazon Prime era. It won't happen overnight. So if you eat a bowl of vegetables today, it's not going to be by tomorrow. But if you adopt a healthy lifestyle, over a period of time it should improve.

CATHY WURZER: All right. Really enjoyed the conversation, doctor. Thank you so much.