Scientists have known for quite some time that bacteria that occur in the gut affect a person’s health, from digestion to allergies. More recently, studies are finding that the microbes that colonize the gut also have an effect on the brain, and can play a role in conditions such as autism, depression and anxiety.
Here to explain more is Dr. Jesse Corry, neurologist at Allina Health’s United Hospital.
Selected Podcast
Your Brain 101: Think With Your Stomach – The Gut Microbiome
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Learn more about Jesse Corry, MD
Jesse Corry, MD
Jesse Corry, MD, is board certified in critical care and neurology, and serves as a neurologist at Allina Health’s United Hospital in St. Paul. His clinical interest is in the stroke continuum of care.Learn more about Jesse Corry, MD
Transcription:
Melanie Cole (Host): Scientists have known for quite some time that bacteria that occur in our gut affect a person’s health from digestion to allergies. More recently, studies are finding that the microbes that colonize the gut also have an effect on the brain and can play a role in conditions such as autism, depression, and anxiety. Here to explain more is my guest, Dr. Jesse Corry. He’s a Neurologist at Allina Health’s United Hospital. Welcome to the show, Dr. Corry. First, let’s explain a little bit about the gut microbiomes and what are those? What do they typically do?
Dr. Jesse Corry (Guest): The gut microbiome is this fascinating thing that we’ve been learning more and more about over the last decade or so. When I was in school, there was – you were told that the gut bacteria help make Vitamin D, and maybe some digestion – that was really about it. As we learn more and more about this fascinating force in our body -- we now know there’s about a hundred trillion bacteria in our gut. That’s more than our body, and there’s about a hundred different species. These bacteria actually have a larger genome, as much as 150 times as large as our own personal genome, so we’re learning more and more that there’s this symbiotic relationship between the bacteria in our gut and or body. The gut bacteria, depending upon if your body is stressed, or depending upon what our diet is, can affect how we’re thinking, how healthy we are, how well we’re absorbing vitamins, things of that nature.
Melanie: How are these bacteria – and people think of their gut and their colon are way down there, and their brain is way up here – but these bacteria also have their own brains. They think a little bit for themselves and do what they’re supposed to do, so how are these things all connected?
Dr. Corry: Okay, so, you first have to -- I think of it as a top-down and a bottom-up approach. Starting in the gut you have a number of different types of bacteria, and depending upon the type of bacteria you’re having, it can affect how you digest certain foods. We know that a lot of bacteria will help make the precursors for various types of neurotransmitters, so if you’ve got one particular pattern of bacteria, let’s say, you’ll be better at making the parts you need to make that serotonin – that feel-good chemical we all have. Or, if you have a certain pattern of bacteria, you’re going to have a better ability to make what’s called brain-derived neurotrophic factor. This is basically a compound that helps your brains’ neurons form impulsive synapses, or how they connect to other neurons.
This is the bottom-up approach where they’re going to be very good at making the precursors to various compounds. That is also going to be really good at helping us – how we sense that we’re full. If you have a certain bacterial pattern, it’s going to tell your brain, “Hey, I’m full. Don’t eat anymore.” So then, obviously, if you’re not eating as much you’re not going to have to worry about things like diabetes or hyperlipidemia, and that sort of stuff.
There’s also this bottom-down [sic] approach, so if the body is stressed, it will go ahead and send its signals to the gut and say, “Hey, I’m nervous,” and this will affect the bacteria in the gut. Certain bacteria work better or are more likely to make other bacteria if the body is healthy and low-stress. If the body is too stressed, then bad bacteria tend to overpopulate. On top of that, then, the gut also has this – it’s like the first line of defense for inflammation. If the gut bacteria is healthy, it’s going to identify various viruses and bacteria that may injure us through all sorts of inflammatory processes -- infections, that sort of stuff. It’s this back-and-forth between the brain making sure the gut is in a happy state and the gut making the things to keep the brain in a happy state.
Melanie: Are there specific diets – as we’re hearing about his connection – what can people do that can promote that healthy gut bacteria or that microbiome.
Dr. Corry: Great question. There’s been more and more work with certain types of diets, the biggest one being the Mediterranean Diet. We all hear about this – people making sure that they have plenty of fruits and vegetables, the good kind of fats – the polyunsaturated fats we see in things like olive oil. There’s also increasing information on what’s called the Nordic diet or the diet of folks in Scandinavia, which is essentially, again, another diet that’s based heavily on more canola oil, also lots of ryes, and good fibers, vegetables, and whatnot.
What these diets seem to have in common is two-fold. First, they have just the right amount of dairy and fermented-type foods. These, then, provide the nutrition the gut microbiome needs – things like leeks and garlic -- the gut microbiome loves this type of fiber, but it also provides the gut microbiome with the right bacteria -- things like yogurt, or kefir – kind of like a natural smoothie. These provide the gut with the proper bacteria we need to help us improve digestion, improve the compounds our gut makes. That’s what seems to be common in these two diets. There are also high amounts of what we call the polyunsaturated fats or the fats we find from fish, from certain nuts, that help lower our overall inflammation in our body, and also help improve our cholesterol profile.
Melanie: Wow, there’s so many things that are going on, and people don’t even realize it. Now, stress plays another important role because we hear about cortisol, and we hear about these gut healthy bacteria that can help our immune system, and thereby, keeping our stressors from breaking down our immune system. The brain, then, also takes in those stressors, and sometimes we focus on these things. Speak about stress and what that could do to the whole system that should be working efficiently, but sometimes, that can put the brakes on a little.
Dr. Corry: Yeah, absolutely. As our body become stressed, those things like cortisol – these bad hormones – take over. Think of it as a two-fold thing. First of all, what do we do when we’re stressed? We eat bad food, right? We’re hitting the piece of pizza. We’re hitting the chips, and the burgers, and stuff, and so you’re not getting the proper nutrients into the gut. You’re not eating the good quality fats, the fats that put you at risk for atherosclerosis, that sort of stuff. You’re eating foods that aren’t necessarily full of the most natural things. You’re eating lots of things that you can’t pronounce on those labels, and so, the body doesn’t know how to digest these things. What you end up doing is you end up promoting the gut to have the bad types of bacteria -- the bacteria that doesn’t necessarily make good vitamin, that don’t necessarily tell your brain, “Hey, I’m full,” that don’t necessarily break down the food into the precursors to things like serotonin and whatnot.
That’s the first part. The next part is when the body is stressed, and our insulin isn’t quite ready – isn’t quite produced as well. The overall milieu – the environment in the gut isn’t really good, so you’re not necessarily going to have a happy environment for those bacteria to reproduce as well as they should. They’re not going to send the signals to the brain as they should. When they make the precursors for things like serotonin, they’re producing less of those types of compounds, so it’s a two-way street.
Melanie: Okay, so we want to try and keep that good, healthy bacteria. We want to make sure to eat these diets that you’ve been discussing, get those good probiotics – prebiotics, the Nordic Diet, the Mediterranean Diet, our DHAs and our Omega-3s, and all of these things that are so healthy. Do you see, Dr. Corry, that there’s a time when bacteria can be used to treat some psychiatric disorders in the same way that doctors have used Prozac and Valium, and because new gut understandings, as this is coming on, equal new treatment opportunities, I would suspect?
Dr. Corry: Absolutely, and this is what I think is one of the most fascinating fields of this emerging data with gut microbiome. There have been a couple of studies now that have looked at the effects of pre- and probiotics on depression, and the thought is less inflammation and less stress maybe makes more serotonin. In some very early, small trials – in a couple dozen patients – they’re finding that, in fact, after about three to eight weeks, of a diet that’s more along the lines of that Nordic and Mediterranean diet where there’s more good quality dairy, good quality fermented foods, that people actually report improved moods and less anxiety.
Similar things have been found with things like bipolar disorder where they do certain dietary interventions, and again, in three to eight weeks, we see there’s a shift in the pattern of the gut flora more along the lines of what we see with healthy people. We see people are reporting to have less symptoms. A similar thing is ADHD, some types of schizophrenia; we’re seeing that if you improve the quality of the gut microbiome, people report that they’re doing better.
Now, this needs to be reproduced in large, multicenter trials, where it’s more real-world environment and not so micromanaged, but I do believe that as time goes on, we’re going to start seeing that you’re not only-- when you go to your psychiatrist, you’re not only going to have a discussion of what medication you need to be on, but also what diet you should be on at the same time.
Melanie: That’s absolutely really fascinating information, and as these treatment opportunities arise, we will talk about them, Dr. Corry, because it’s really so interesting how the brain – and you’re a neurologist – is now affecting the gut, and vice-versa. It’s something that really people can take, and take this information that you have given us today, and use it tonight by taking those probiotics, by getting that healthy flora in a good, strong way. Thank you, so much, for being with us, today.
Dr. Corry: It’s great to be here. Thank you, so much.
Melanie: You’re listening to The Well Cast with Allina Health, and for more information, you can go to AllinaHealth.org, that’s AllinaHealth.org. This is Melanie Cole. Thanks, so much for listening.
Melanie Cole (Host): Scientists have known for quite some time that bacteria that occur in our gut affect a person’s health from digestion to allergies. More recently, studies are finding that the microbes that colonize the gut also have an effect on the brain and can play a role in conditions such as autism, depression, and anxiety. Here to explain more is my guest, Dr. Jesse Corry. He’s a Neurologist at Allina Health’s United Hospital. Welcome to the show, Dr. Corry. First, let’s explain a little bit about the gut microbiomes and what are those? What do they typically do?
Dr. Jesse Corry (Guest): The gut microbiome is this fascinating thing that we’ve been learning more and more about over the last decade or so. When I was in school, there was – you were told that the gut bacteria help make Vitamin D, and maybe some digestion – that was really about it. As we learn more and more about this fascinating force in our body -- we now know there’s about a hundred trillion bacteria in our gut. That’s more than our body, and there’s about a hundred different species. These bacteria actually have a larger genome, as much as 150 times as large as our own personal genome, so we’re learning more and more that there’s this symbiotic relationship between the bacteria in our gut and or body. The gut bacteria, depending upon if your body is stressed, or depending upon what our diet is, can affect how we’re thinking, how healthy we are, how well we’re absorbing vitamins, things of that nature.
Melanie: How are these bacteria – and people think of their gut and their colon are way down there, and their brain is way up here – but these bacteria also have their own brains. They think a little bit for themselves and do what they’re supposed to do, so how are these things all connected?
Dr. Corry: Okay, so, you first have to -- I think of it as a top-down and a bottom-up approach. Starting in the gut you have a number of different types of bacteria, and depending upon the type of bacteria you’re having, it can affect how you digest certain foods. We know that a lot of bacteria will help make the precursors for various types of neurotransmitters, so if you’ve got one particular pattern of bacteria, let’s say, you’ll be better at making the parts you need to make that serotonin – that feel-good chemical we all have. Or, if you have a certain pattern of bacteria, you’re going to have a better ability to make what’s called brain-derived neurotrophic factor. This is basically a compound that helps your brains’ neurons form impulsive synapses, or how they connect to other neurons.
This is the bottom-up approach where they’re going to be very good at making the precursors to various compounds. That is also going to be really good at helping us – how we sense that we’re full. If you have a certain bacterial pattern, it’s going to tell your brain, “Hey, I’m full. Don’t eat anymore.” So then, obviously, if you’re not eating as much you’re not going to have to worry about things like diabetes or hyperlipidemia, and that sort of stuff.
There’s also this bottom-down [sic] approach, so if the body is stressed, it will go ahead and send its signals to the gut and say, “Hey, I’m nervous,” and this will affect the bacteria in the gut. Certain bacteria work better or are more likely to make other bacteria if the body is healthy and low-stress. If the body is too stressed, then bad bacteria tend to overpopulate. On top of that, then, the gut also has this – it’s like the first line of defense for inflammation. If the gut bacteria is healthy, it’s going to identify various viruses and bacteria that may injure us through all sorts of inflammatory processes -- infections, that sort of stuff. It’s this back-and-forth between the brain making sure the gut is in a happy state and the gut making the things to keep the brain in a happy state.
Melanie: Are there specific diets – as we’re hearing about his connection – what can people do that can promote that healthy gut bacteria or that microbiome.
Dr. Corry: Great question. There’s been more and more work with certain types of diets, the biggest one being the Mediterranean Diet. We all hear about this – people making sure that they have plenty of fruits and vegetables, the good kind of fats – the polyunsaturated fats we see in things like olive oil. There’s also increasing information on what’s called the Nordic diet or the diet of folks in Scandinavia, which is essentially, again, another diet that’s based heavily on more canola oil, also lots of ryes, and good fibers, vegetables, and whatnot.
What these diets seem to have in common is two-fold. First, they have just the right amount of dairy and fermented-type foods. These, then, provide the nutrition the gut microbiome needs – things like leeks and garlic -- the gut microbiome loves this type of fiber, but it also provides the gut microbiome with the right bacteria -- things like yogurt, or kefir – kind of like a natural smoothie. These provide the gut with the proper bacteria we need to help us improve digestion, improve the compounds our gut makes. That’s what seems to be common in these two diets. There are also high amounts of what we call the polyunsaturated fats or the fats we find from fish, from certain nuts, that help lower our overall inflammation in our body, and also help improve our cholesterol profile.
Melanie: Wow, there’s so many things that are going on, and people don’t even realize it. Now, stress plays another important role because we hear about cortisol, and we hear about these gut healthy bacteria that can help our immune system, and thereby, keeping our stressors from breaking down our immune system. The brain, then, also takes in those stressors, and sometimes we focus on these things. Speak about stress and what that could do to the whole system that should be working efficiently, but sometimes, that can put the brakes on a little.
Dr. Corry: Yeah, absolutely. As our body become stressed, those things like cortisol – these bad hormones – take over. Think of it as a two-fold thing. First of all, what do we do when we’re stressed? We eat bad food, right? We’re hitting the piece of pizza. We’re hitting the chips, and the burgers, and stuff, and so you’re not getting the proper nutrients into the gut. You’re not eating the good quality fats, the fats that put you at risk for atherosclerosis, that sort of stuff. You’re eating foods that aren’t necessarily full of the most natural things. You’re eating lots of things that you can’t pronounce on those labels, and so, the body doesn’t know how to digest these things. What you end up doing is you end up promoting the gut to have the bad types of bacteria -- the bacteria that doesn’t necessarily make good vitamin, that don’t necessarily tell your brain, “Hey, I’m full,” that don’t necessarily break down the food into the precursors to things like serotonin and whatnot.
That’s the first part. The next part is when the body is stressed, and our insulin isn’t quite ready – isn’t quite produced as well. The overall milieu – the environment in the gut isn’t really good, so you’re not necessarily going to have a happy environment for those bacteria to reproduce as well as they should. They’re not going to send the signals to the brain as they should. When they make the precursors for things like serotonin, they’re producing less of those types of compounds, so it’s a two-way street.
Melanie: Okay, so we want to try and keep that good, healthy bacteria. We want to make sure to eat these diets that you’ve been discussing, get those good probiotics – prebiotics, the Nordic Diet, the Mediterranean Diet, our DHAs and our Omega-3s, and all of these things that are so healthy. Do you see, Dr. Corry, that there’s a time when bacteria can be used to treat some psychiatric disorders in the same way that doctors have used Prozac and Valium, and because new gut understandings, as this is coming on, equal new treatment opportunities, I would suspect?
Dr. Corry: Absolutely, and this is what I think is one of the most fascinating fields of this emerging data with gut microbiome. There have been a couple of studies now that have looked at the effects of pre- and probiotics on depression, and the thought is less inflammation and less stress maybe makes more serotonin. In some very early, small trials – in a couple dozen patients – they’re finding that, in fact, after about three to eight weeks, of a diet that’s more along the lines of that Nordic and Mediterranean diet where there’s more good quality dairy, good quality fermented foods, that people actually report improved moods and less anxiety.
Similar things have been found with things like bipolar disorder where they do certain dietary interventions, and again, in three to eight weeks, we see there’s a shift in the pattern of the gut flora more along the lines of what we see with healthy people. We see people are reporting to have less symptoms. A similar thing is ADHD, some types of schizophrenia; we’re seeing that if you improve the quality of the gut microbiome, people report that they’re doing better.
Now, this needs to be reproduced in large, multicenter trials, where it’s more real-world environment and not so micromanaged, but I do believe that as time goes on, we’re going to start seeing that you’re not only-- when you go to your psychiatrist, you’re not only going to have a discussion of what medication you need to be on, but also what diet you should be on at the same time.
Melanie: That’s absolutely really fascinating information, and as these treatment opportunities arise, we will talk about them, Dr. Corry, because it’s really so interesting how the brain – and you’re a neurologist – is now affecting the gut, and vice-versa. It’s something that really people can take, and take this information that you have given us today, and use it tonight by taking those probiotics, by getting that healthy flora in a good, strong way. Thank you, so much, for being with us, today.
Dr. Corry: It’s great to be here. Thank you, so much.
Melanie: You’re listening to The Well Cast with Allina Health, and for more information, you can go to AllinaHealth.org, that’s AllinaHealth.org. This is Melanie Cole. Thanks, so much for listening.