10/04/2024

How Gut Microbes Are Linked To Stress Resilience

17:20 minutes

A gastrointestinal tract surrounded by graphics of microbes.
Image collage by Emma Gometz

The phrase “go with your gut” is often used to say one should follow their intuition in the face of a big decision. Recent research in the journal Nature Mental Health shows the gut really could have a big impact on mental health and decision-making.

This study shows a clear link between people who handle stressful situations well and certain biological signatures in their microbiomes. Certain metabolites and gene activity in study participants were associated with high emotional regulation and cognition. These more resilient participants also had reduced inflammation and improved gut barrier integrity.

The study builds on previous research that shows the brain and the gut are closely linked, and that a dysregulation in one can lead to a dysregulation in the other. Lead author Dr. Arpana Church, co-director of UCLA’s Microbiome Center and associate professor of medicine, joins Ira to talk about the study. They also discuss how probiotics could someday be a promising treatment for mental health conditions.


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Segment Guests

Arpana Church

Dr. Arpana Church is a neuroscientist and the co-director of UCLA’s Goldman-Luskin Microbiome Center in Los Angeles, California.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. There’s been a growing body of research that connects what happens in our gut to what happens in our brain. Our gut contains a huge bundle of nerves, one major one, the vagus, leading right up to our gray matter. The gut microbiome is, to me, one of the most interesting frontiers of medicine. You’ll know that if you listen to this program.

And recent research builds on this field showing a clear distinction between the microbiomes of people who are resilient to stress and those who are not. Joining me to talk about this work published in the Journal Nature Mental Health, is the lead author of the study, Dr. Aparna Church, co-director of UCLA’s Goodman Luskin Microbiome Center, based in Los Angeles. Dr. Church, welcome to Science Friday.

ARPANA CHURCH: Thank you for having me on here.

IRA FLATOW: How did you get involved in this?

ARPANA CHURCH: So I was actually– my path to poop was actually from the top versus top down versus bottom up.

IRA FLATOW: Very nice. Very nicely put.

ARPANA CHURCH: So I am actually a psychologist with neuroscience expertise. And I started in the psychology world. And when I came to UCLA, started working in the Division of Digestive Diseases and just realizing like we’re just so interconnected. As a medical field, we are so siloed. And we tend to– for example, if you have a cardiac condition, you go to a cardiologist. If you have a lung condition, you go to a pulmonologist. We’re just so siloed.

But that’s not the way everything works. And as I said, I started from the brain down and realizing that brain was this computer system, this hard drive that controlled all these other organs really was how it started. And then looking at how everything is interconnected. And then being a psychologist, realizing like when people started to talk about mental health and started to use phrases like, I feel sick to my stomach. My head hurts. And just realizing how everything was just interconnected. And so it just seemed like a natural path for me to look at the whole body as a system.

And I don’t just only look at the whole body as a system, but I also look at the environment, because fortunately or unfortunately, we don’t live in bubbles. We’re interconnected to each other. We’re connected to what’s happening in our environment. That’s why I kind of got into this.

IRA FLATOW: Let’s talk about what you found in the study. Tell us.

ARPANA CHURCH: Sure. So, I mean, I think it’s important, first of all, for us to talk about stress. When you think about stress, it’s an inevitable part of life. So studying how we handle stress can really help us understand how to prevent developing diseases. If you think about it, 77% of Americans report physical symptoms caused by stress. And 33% of Americans report that they’re living with extreme stress. So that accounts for over $300 billion that are lost annually in stress related health care costs or even missed work.

And if you think about it, stress is linked to the onset and progression of disease. It can be mental health illnesses like anxiety, depression, or even physical health, issues like obesity, irritable bowel syndrome, cardiovascular disease. In fact, if you think about stress, it’s almost equal to smoking five cigarettes per day.

IRA FLATOW: Is that right?

ARPANA CHURCH: And also think about stress, it’s not just when you’re an adult. It can happen in any form. It can happen any point in the life span from infant to adulthood. Think about a child that’s left in the crib crying. That’s stressful. Think about kids going to school. That’s stressful, making friends, being bullied. That’s all stressful. And then you’re an adult. Economic hardships, and then all the way into old age, you lose a loved one, death of a spouse or a family member.

So stress is just part of our life. It’s inevitable. So for this study, that’s what really was the impetus of looking at the study. I really wanted to know what it was about stress and why is it, because we all experience stress? Every one of us, in some form or another experiences stress. So why is it that some people who experience stress do really poorly? And what is it about those resilient individuals, those individuals who have this grit.

What is it about them that who, despite experiencing stress, are really highly resilient. And so that really was the question. And honestly, in medicine and in research, we’re always looking at the negative, we’re always looking at disease. So I really wanted to flip the script and say like, what is it about the people that do really well? How about studying those individuals and maybe that might give us some insight?

IRA FLATOW: And you went by looking into people’s guts to find the answer.

ARPANA CHURCH: We actually– we did a lot of things. So we had 116 adult individuals. And we gave them a whole bunch of questionnaires and physical and psychological exams. So we measured things like anxiety, depression. We also measured resilience. And the way we measured resilience was using something known as the Connor Davidson Resilience Scale, which is basically this 10-item scale that measures things like positive acceptance of change, tolerance of negative affect, tenacity, the ability to recover after stressful events.

| there are really five factors of resilience. One is personal competence, trust in one’s instincts, positive acceptance of change, sense of control, spiritual influences. And we also measured cognitive functioning. Then we also put them in the MRI scanner and we basically looked at not only their brain structure, but also the connectivity of different brain regions. So how one brain region is connected to another. And then we collected their stool in order to look at their microbiome abundance and function.

IRA FLATOW: That was a great windup. Here’s the pitch. What did you find that was different in one person or one kind of stress handler than another?

ARPANA CHURCH: Yeah, so the highly resilient individuals, the ones that did really well with stress, if you looked at the brain, we found that there were brain features or brain signatures, features and functions that were related to improved emotional regulation and cognition. So what that means is if you think about the brakes in your car, right, if you tap the brakes a little bit, your car stops, great working brakes. But you’re in in a near car collision and your brakes are not working that well, and you’re jamming down your brakes and you’re pressing really hard, that basically shows that those brakes are not working that great. So that’s the same thing.

So those cognitive, those control regions of the brain were working really well. They were able to modulate like these emotional or these hyperarousal regions in the brain. And then we also saw that at the gut level, there were these metabolites and these transcriptomes that were linked to reduced inflammation and also were related to better gut barrier integrity. We also saw that these individuals were very extroverted, they were very mindful. And this was really interesting. I was blown away with this, but they were also kinder and non-judgmental.

IRA FLATOW: We could all use some of that now.

ARPANA CHURCH: Oh my god, I mean, it says something. I talk about this, just being very easygoing and grateful and accepting really means something. So maybe not being that reactive or my God, I can’t believe somebody did that to me or maybe just like, OK

IRA FLATOW: Well, my question is the chicken or the egg? I mean, are they kinder because of what’s going on in their guts or is that influenced the other way?

ARPANA CHURCH: People always ask this question, whether they’re talking about whether it’s the brain that’s messed up or if it’s the microbiome that’s messed up, or is it our personalities that need adjusting. Who knows. This chicken and egg question always comes up in science. And to be honest, we don’t really know whether it’s the chicken or egg. And I like to say, does it really matter? That the important thing to remember is that because everything is connected, we can stop the cycle and we can influence. Because if you think about it, everything is connected. It’s bi-directional. It’s like the cyclical loop.

So what I like to say, who cares what comes first or after? The point is that we can break the cycle and intervene and change things. That’s what we really need to be asking is, can we change it? And how can we change it?

IRA FLATOW: Well that’s– you anticipated my next exact question. Can we change it? And how can we change it? I mean, from what you’ve learned in your study, you found biological markers. You found regions in the brain that act differently, regions in the gut that act differently. How do you use that knowledge?

ARPANA CHURCH: It’s very exciting because your brain is very malleable. Your microbiome is very malleable. And guess what, even your personalities are very malleable. So I love this kind of integrated, what I call whole person or systems biology work because it shows that we can come up with these multi-modal, these multi-pronged interventions that are designed to provide targeted support, whether we’re talking about– at the brain level.

So it could be more resilience training, it could be stress reduction. But even at the behavioral level, think about, OK, maybe teaching people to be more grateful, more easygoing, getting along with people, being more extroverted, maybe not being so as neurotic. Just those kinds of things, being more mindful and non-judgmental.

And then at the microbiome level, people always talk about my God, how can I change my microbiome. And I always tell people, guess what, the microbiome is the easiest thing to change. You can do things today that will change your microbiome within 24 hours, even by tomorrow. So I know when people think about changing the microbiome, they talk about, fecal microbiome transplants or taking crapsules. And I’m like, let’s not even go there. Let’s just talk about easy things, things that we know that work.

So we can talk about probiotics or prebiotics that can change your microbiome, but even something easier than that, your diet, it’s the most accessible, easiest thing to change your diet. And I like to tell people, think about when you’re stressed. Some of us, either eat a lot and we tend to go for those high calorie foods or some of us, just don’t eat, like we go into this kind of I don’t feel like eating, I’m too stressed.

But really just targeting your diet and eating a healthy diet, a diet that’s balanced, that’s diverse, that’s rich in fiber fermented foods, I think that that’s the easiest way to do it. And I always talk about eating diets rich in diverse fruits and vegetables and I call them ABCs, always be counting. And I don’t mean counting calories. I mean counting at least 30 different vegetables and fruits per week.

IRA FLATOW: Wow.

ARPANA CHURCH: Really help maintain your healthy microbiome. If there’s anything that you take away from today, take that away. ABCs always be counting, 30 different fruits and vegetables per week.

IRA FLATOW: Wow, that’s not the American diet. But I want to know.

ARPANA CHURCH: But people always say that, that’s so hard. How can I do 30? Oh my god, I can’t do that. You’re crazy. I have a hard time just getting two vegetables per week. And I tell people, it’s really easy once you start counting. Let me give you an example, if you end up having a bowl of soup or a bowl of stew, think about what you’re putting in that stew, right.

You’re putting tomatoes, onions, garlic, maybe some kind of herb, maybe some kind of spice, like turmeric or pepper, that’s already five or six right there. You add some carrots, maybe. That’s seven. That’s seven already in one meal. So 30 per week, that’s easy.

IRA FLATOW: Wow. You mentioned the term very quickly that I have to go back. I have to replay the tape in my mind. You talked about when we were talking about changing your gut health and you talked about probiotics and crapsules, crapsules. I think I know what that is. But you have to tell me.

ARPANA CHURCH: It’s just a made up word.

IRA FLATOW: I love it.

ARPANA CHURCH: So there’s something known as fecal microbiome transplant, where you basically taking the microbiome of somebody else and you’re ingesting it, whether you’re ingesting it through a capsule. There have been stories of people like making milkshakes. I mean, this I know is disgusting, but people have talked about making milkshakes and having it that way or even put it up through your colon.

So those are ways that you can have these microbial transplants. But if you’ve heard stories of people who have tried to do these kinds of things, it’s not only first of all, it’s not regulated. It’s very risky. It can be very complicated. But secondly, whatever that other person ends like has, you will end up getting that. So you might end up treating one thing, but then you might end up getting for example, like say, for example, I decided to take my husband’s poop and somehow ingest it, whether it’s through a capsule or whatever.

If he has acne, I will end up getting acne.

IRA FLATOW: No.

ARPANA CHURCH: If he has depression, I will end up getting depression. So it’s really very

IRA FLATOW: Unintended consequences.

ARPANA CHURCH: Yes, unintended. And it’s not regulated, and it’s just very complicated. So I really– I really think they’re crap. They’re crapsules. I really don’t advise.

IRA FLATOW: So you don’t recommend a fecal microbiome transplant from the stress resilient people into people who might need it because there’s unintended consequences of that.

ARPANA CHURCH: Unintended, and I just don’t think the research is there. I think if we really need to be doing more research, maybe we need to be doing more research on creating targeted probiotics or even prebiotics or synbiotics. So, for example, like we could take the microbial markers from this study looking at the bacteria or the metabolites that are impacted and creating a supplement from that and then testing that to see if that works. That to me, is safer. It’s more regulated.

IRA FLATOW: Is that on the horizon, you think, to do that?

ARPANA CHURCH: This is where the whole motive of the Goodman Luskin Microbiome center is to be able to develop these targeted either brain or gut microbiome targeted treatments. That’s the whole point of the center, is that we do these large studies and we find these signatures. And then. OK, so people are then. OK, now what? OK, fine. Great, you found this signature. How does this help me?

Sure we can give them interim solutions like, hey maybe change your diet. But I think these kind of tested and engineered supplements are definitely on the horizon. In fact, we have one clinical trial that we’re doing right now based upon a patented probiotic blend that actually came out of a study from the lab.

IRA FLATOW: Interesting. I mean, I hear you saying that we are really so connected to our poop, aren’t we? Yeah, more than people realize.

ARPANA CHURCH: Yes.

IRA FLATOW: Well, there you have it. This has been highly fascinating, Dr. Church. This is– I think I’m certainly a better person for learning about poop and the microbiome and all the things you brought with you to share with us today. Thank you for taking time to be with us today.

ARPANA CHURCH: Thank you for having me.

IRA FLATOW: Dr. Arpana Church, co-director of UCLA’s Goodman Luskin Microbiome center, based in Los Angeles.

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