In this podcast, I discuss the gut-brain axis with Dr. Jeff Moss. This was a fascinating conversation about the latest research on the connection between gut microflora and it's intimate connection to the brain and nervous system. We talk about this connection with neurotransmitter imbalances, autonomic nervous system dysfunction, Alzheimer's disease, Autism, gut healing strategies and much more.
Here is the transcript of my conversation with Dr. Jeff Moss on the Gut-Brain Axis:
Dr. Hedberg: Okay, well, welcome, everyone. This is Dr. Hedberg, and thanks for tuning into "The Dr. Hedberg Show." I've got a very special guest today, Dr. Jeff Moss. And Dr. Moss is a graduate of the University of Michigan Dental School 1974. He practiced dentistry in Grand Rapids, Michigan until 1985. And he employed clinical nutrition in that practice, and he decided to use that experience and enter the professional supplement industry.
So, for the last 24 years, Dr. Moss has operated Moss Nutrition, which supplies the Moss Nutrition professional line of supplements to practitioners. And, since 2000, he has served as adjunct faculty at the University of Bridgeport Nutrition Institute, starting with the vitamins and minerals class and most recently adding the assessment in nutrition class to his teaching responsibilities.
He's co-authored the textbook, the "Textbook of Nutritional Medicine" by Dr. Melvyn Werbach, and Dr. Moss was president of the International and American Associations of Clinical Nutritionists from August 2000 to June 2001.
Moss Nutrition's website is mossnutrition.com, and those of you who are patients of mine know that I'm a big fan of Moss Nutrition products because of the quality and because of all the research behind their products, and just fantastic customer service, and just a great company to work with across the board. So Dr. Moss has definitely been a mentor of mine. He's one of the only doctors out there in the functional medicine world who I listen to and respect, so I'm really excited to have him on. Jeff, thanks for joining me.
Dr. Moss: Well, thanks so much for having me.
Dr. Hedberg: So today we're gonna be talking about the gut-brain axis. This is a topic that is kind of sweeping the functional medicine landscape with good reason. We've been addressing this issue for a long time, but we're learning more and more about how the gut flora affect extraintestinal aspects of the body, and the brain, and the rest of the body system. So why don't we jump in, and can you just talk a little bit about how the gut microbiota actually interact with our nervous system?
Dr. Moss: Sure, there are really several different ways that it does it, and before I get into all of the ways, I guess the big picture here is that why this is so interesting and why it is important and so exciting is, because of the way we've traditionally viewed any type of central nervous system issue, either behavioral or neurodegenerative, we've kind of viewed as the central nervous system kind of hanging out there in space. We view the blood-brain barrier as basically impermeable to a lot of different things, and because of that the way we viewed it and the way we intervene was basically looking at it directly. There really wasn't connected to anything else in the body.
And I remember I got this very early on as a dentist. You know, the head is just kind of detached from everything else from a physiologic and mostly in terms of a diagnostic and clinical interventional therapeutic standpoint, and so I think that's the big picture here before we get into the complexities even if some of it's a bit difficult to understand. The big picture here is that the brain is incredibly influenced by what else is going on in the body, and particularly what's going on in the gut. So, with that in mind, there are really several different ways.
Number one is what is classically known...we have neuroanatomical pathways, the autonomic nervous system, the vagus nerve, the classic anatomy, and the gut flora can have a direct impact on that, but really that's only the beginning. It also can have impact on stress physiology, what is known as the hypothalamic-pituitary-adrenal axis.
Research shows that gut microflora...and I'll talk about how it does that in just a second, but it has an impact on stress physiology, the endocrinology, and the pathways involved, and how we respond to stressors. There, of course, is the immunologic impact. Gut microflora have a direct impact on the immune system in the gut, and most immune cells are in the gut, but beyond that, there's kind of a ripple effect where it has an impact on systemic immunity.
And the reason that is important, we now understand that behavioral and neurodegenerative illnesses are primarily inflammatory, that there is a neurologic immune system mediated by some cells in the brain called microglia. They're like inflammatory cells, if you will, like an inflammatory cell, like a lymphocyte or a neutrophil, but it's in the brain. They call them microglia, and gut microflora can upregulate activity of this microglia the same way they might do it systemically with the white blood cells we're all familiar with. So that's another way that it can do it.
It also has an impact on the blood-brain barrier. What I mentioned before, this idea that it's kind of impermeable, well, it will have an impact on the blood-brain barrier and may basically make it more permeable. We know that imbalances of gut microflora, for example, will affect the gut barrier, creating leaky gut. Well, the gut microflora can also create leaky brain, for lack of a better term.
The factors that are involved in terms of creating this scenario, gut microflora are responsible for producing short-chain fatty acids, and from a positive aspect, these short-chain fatty acids are well-known to [inaudible 00:06:47] butyric acid can improve the health of the gut lining. But there are other short-chain fatty acids, again, pre-produced, and when there's an imbalance, these short-chain fatty acids can actually get into the brain. If there's a leaky gut, they circulate, go through the leaky blood-brain barrier, get into the brain and cause disturbances in that way.
They also produce something that most of us aren't familiar with, GABA, gamma-Aminobutyric acid, which can have an impact. Another big way that the gut microflora interact, as most of us know, we all know about serotonin, and we tend to think about serotonin as a central nervous system issue. We're all familiar with SSRIs for depression. Well, in actuality, most of the serotonin is not produced in the brain. When you look at the total body production, most of it is produced in the intestine, and gut microflora, when there are imbalances, can affect the serotonin production in the gut. And this is fairly well-known as being related to...contributing to IBS, constipation, different types of IBS manifestations. But we now know that the serotonin produced in the gut, which is influenced by gut microflora, can also affect the central nervous system. It's not just a systemic IBS-type scenario.
Finally, I did wanna talk a bit more about its impact on the vagus nerve. This is significant. And the vagus nerve, of course, as we know from our anatomy days, this is a very large nerve that has several different functions, part of which relate to the gut. But, again, this can have systemic manifestations also.
Dr. Hedberg: Yeah, and one of the things that I see very frequently in practice which ties in with everything you just talked about links to early adverse life events. And if we go back to childhood and we look at antibiotic usage at a very young age, and not just antibiotics, but not being breastfed, C-section, poor diet, and then all those psychological and physical traumas that people can go through as a kid.
There are so many connections there kind of setting someone up for some difficulties later in life, not just with their microflora, but with mood disorders, and irritable bowel, SIBO, inflammatory bowel, and things like that. Did you have anything to add to that regarding early adverse life events and a disrupted gut-brain axis?
Dr. Moss: Yeah, you make a very good point. For about 100 years now, we've been conducting this uncontrolled experiment on manipulation of our microbial environment, both in the world around us and the world inside of us. Antibiotic use is about 100 years now, and it starts, of course, for most people in terms of direct administration, some people, as you say alluded to, very early on. But when you look at the antibiotics in the food supply, it probably starts in utero, before birth.
And so, yeah, you make a very good point, that in our society after a 100 years of antibiotic use, we have created some disturbances in our gut microflora let alone the microflora world around us. Now, unfortunately, this, of course, is not all black and white. Am I saying that we shouldn't have had antibiotics? History of infectious disease suggests that there's a lot of benefit, and I'm not going to argue against that for a minute.
There are certain scenarios of certain types of bacterial infections, and certain populations, certain individuals, particularly very young and the very elderly, where antibiotics have definitely...the benefits have definitely outweighed the risks. What's the problem, I think, is we have seen gross overuse and misuse.
If they were used the way that they intended in the '20s, when penicillin was first discovered, limited occasional use for significant bacterial infections, I don't think we would be having this conversation that we're having today, or we'd have this conversation, but it would've taken a very different path. It's the overuse and the misuse that has really put us where we're at. So I'm not condemning antibiotics. I'm condemning poor decision-making about antibiotic use.
Dr.