Colorado researchers think they might be able to help veterans with traumatic brain injury and PTSD by improving the health of their gut microbiome.
Dr. Lisa Brenner, a clinical research psychologist at the Department of Veterans Affairs and the University of Colorado School of Medicine, leads the study. Chris Lowry, of Department of Integrative Physiology at the University of Colorado Boulder, is also involved in the study, which uses the probiotic Lactobacillus rhamnosus to treat the veterans.
Here’s what we learned from Brenner and Lowry about the so-called “gut-brain axis” and about the current study, which is just wrapping up. They say results will be released next year.
Dr. Lisa Brenner on what started her thinking about a connection between veterans with PTSD and their gut microbiome:
“People were coming back from Iraq and Afghanistan with both PTSD and brain injury symptoms often related to being exposed to blasts. One soldier I talked to started talking to me about how in addition to his brain injury symptoms, his guts hurt for several weeks after he was exposed to a blast. And I couldn't help but think about the gut and the brain together after that conversation.”
“We often think about PTSD as being a brain-based condition, but it turns out that lots and lots of veterans and others who have PTSD also have gut problems, including irritable bowel syndrome and the idea for this based on our previous work is if you could take these probiotics that have these very specific effects that you could decrease inflammation, calm the whole system down and perhaps decrease the symptoms.”
Brenner on the current study using a probiotic to treat veterans:
“We've been consistently trying to identify probiotics that can help modulate the immune system and help calm things down a bit. The current probiotic that we're using is Lactobacillus rhamnosus, but I also really want to highlight that you can go to the store and you can buy a lot of different probiotics, but we are setting very specific strains of these specific bacteria that we think have this effect.”
“The concern is when folks go out and buy things, they have maybe four or more strains of probiotic in them, and that makes it even more difficult to actually know what is having an impact, if anything. And so we've been very focused on studying one strain at a time that has specific effects that we think will be useful.”
Christopher Lowry on the definition of a healthy gut microbiome:
“The best estimate of a healthy microbiome that we have to date is a microbiome that has high diversity. When we talk about diversity of the gut microbiome, we're talking about two features. One is the richness. In other words, how many different types of microbes do you have in your gut microbiome? And the other feature is evenness. How evenly distributed are the types of bacteria that are present? Those two features together are what we call alpha diversity. And so higher alpha diversity is considered to be more healthy.”
“Things like exercise, healthy diet consumption of lots of fruits and vegetables are associated with the high diversity of the gut microbiome. So there's a good correlation between high diversity and healthy outcomes, both physical health and mental health.”
Brenner on the definition of a healthy gut microbiome:
“I think at the beginning when we were thinking about healthy and unhealthy gut microbiome and this group of people has this and it's healthy and this group of people has this and it's unhealthy, my sense is we're moving a little bit away from that. I think what we're finding is maybe it looks generally okay except for they may have one or two or three or however many particularly bad actors or absent actors that are not doing the jobs that we need them to do in the gut, that there may be these key players that are missing or in overabundance that actually create specific things that are less healthy rather than your whole gut being unhealthy.”
Lowry on a resource tool for people interested in probiotics:
“I like to point people toward this resource guide to probiotic products in the U.S. and the reason I like it is that it's put together by a consortium of people that don't have any kind of conflict of interest. So they're not selling a product themselves, they're just evaluating the data, and they've undergone a very arduous task of looking at all the clinical trials that have been done and then evaluating the evidence for individuals, whether they're children or women or men with different conditions. So they evaluate conditions like diarrhea and constipation, but they also have a mental health category.”
Brenner on what she recommends for maintaining a healthy gut microbiome:
“A diverse diet with many different vegetables, exercise, sleeping well, all those things are really good for gut health.”
