Studies demonstrating gut-brain dysfunction and its effects on health
There was one published last year in the National Review of Gastroenterology & Hepatology and I’ll quote from the conclusion. It said “IBS is thought to be the result of disturbed neural function along the gut-brain axis.” So that makes it pretty clear.
DANNY RODDY: That’s big news.
CHRIS KRESSER: Yeah, there’s an interesting thing here where for a lot of years doctors told people with IBS it was all in their head. And that’s really not a nice thing to say, but it’s true. The thing is it’s not true in the way that the doctors meant it. You know what I’m saying? They meant you just need to get over this, or you’re just imagining it is what they meant. But what is true is that it is in your head, cause that’s where your brain is. And if the gut is malfunctioning then the brain is involved, and vice-versa. So it is all in our head but not in the sense that we’re to blame for it or we’re just making it up.
Another study in 2005 found that IBS patients have increased activation of pain circuits and decreased activation of pain inhibition circuits. So this is interesting cause, I don’t know if you remember this but when we had Kurt Harris on we were talking about fructose malabsorption and the gas that produces, and the difference in the way that’s experienced with people with IBS and people without IBS. And they found in that study that people with IBS and without IBS had the same amount of gas produced with fructose malabsorption, but it didn’t even bother the people who didn’t have IBS. It only was painful and uncomfortable in people with IBS. And so that’s what this is about here, people with IBS have a decreased pain threshold, increased activation of pain circuits and then decreased ability to turn off the pain circuits.
DANNY RODDY: So they’re just in a hyper-sensitive state?
CHRIS KRESSER: Exactly. Yeah, so it’s not even necessarily the amount of gas that’s produced, it’s how they experience it. And again it’s not their fault, it’s not something that they are imagining it’s a real neuro-physiological pathway. Journal of Clinical Psychiatry 2001, this is crazy, 50-90% of IBS patients seeking treatment have a psychiatric disorder. Woah. This includes panic disorder, anxiety, social phobia, PTSD or a major depressive disorder. I mean, if that doesn’t sum it all up, give you some strong evidence for an association between the gut-brain connection I don’t know what does.
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We also know that depressed people secrete greater quantities of inflammatory cytokines than normal people and this has been extensively studied by… Dr. Michael Maes and his colleagues in Belgium, and they’ve published like 40 papers demonstrating that chronic immune activation and the associated increase in cytokine production is characteristic of depression. So you have all those different ways that the gut can affect the brain and particularly inflammation in the gut can cause inflammation in the brain. So the takeaway here is that anxiety and stress and IBS and IBD, the gut and the brain, they’re all part of the same axis, they always go together. Every stressful event that we experience in life increases the plasticity of stress pathways in the brain which means it makes the brain essentially more efficient at running stress pathways. And there’s a saying in functional medicine, fire in the gut, fire in the brain. Which sums it up pretty well. Digestive function will start to fail immediately after the brain starts to fail, and the inter intestinal gut mucosa in the brain themselves don’t have any pain fibers which is why brain-gut, you don’t see people coming into the clinic going my brain hurts. My brain feels really inflamed can you help me? They come in saying I can’t eat any foods, I’ve got gas and bloating, I can’t remember anything, I used to be able to concentrate for long periods and now I can’t, I’ve got cold hands and feet, and I’ve got this toenail fungus and it won’t go away, this is what people say when they’ve got a gut-brain issue. And as a patient or a clinician if you ignore the role of the brain in addressing gut issues, success is definitely gonna be limited. Probiotics, and HCL, and diet are all very important of course. But it’s possible to do all of that right and still have gut symptoms as I’ve experienced directly myself, and as a lot of my patient’s have experienced. So this is one of the reasons that I’m always harping on the importance of sleep, and stress management, and cultivating pleasure, because these are all things that we can do to help our brain function better.