The Role of the Microbiome in Food Allergies
DR. WEITZ'S BLOG, RATIONAL WELLNESS PODCAST
The Role of the Microbiome in Food Allergies with Dr. Tom Fabian – Rational Wellness Podcast 233
Tom Fabian, PhD speaks about the Role of the Microbiome in Food Allergies with Dr. Ben Weitz. Airdate: 11/17/21
1:30 Food allergies vs Food sensitivities vs Food intolerances. – Food allergies are mediated by Immunoglobulin E and mast cells tend to play a role. Patients with true food allergies may have very severe reactions such as anaphylaxis and they are immediate after eating that food. Food sensitivities are typically mediated by IgG and they tend to be delayed reactions. They can also be mediated by IgM and IgA, though these are less well defined. Secretory IgA, which is reported on the GI-MAP stool test from Diagnostic Solutions, is known to play multiple roles in the gut both in terms of reacting to things thought to be threats, but also a protective role in terms of commensal bacteria in which IgA binds to these commensals and by binding to normal food antigens, it helps to reduce or prevent over-reactivity from the immune system.
7:13 A Food Intolerance is a non-immune mediated reaction to a food, such as a carbohydrate intolerance or a histamine intolerance, which can be mediated by a lack of diamine oxidase enzyme, which keeps you from breaking down histamine.
8:46 A healthy microbiome can play a role in our oral tolerance to foods that might otherwise be harmless. Our immune system has a balance of pro-inflammatory and anti-inflammatory. Immune tolerance is a mechanism by which the immune system restrains overreaction, which applies to food allergies, and involves Treg cells. There are a number of products from the microbiome that promote Treg cells that promote immune tolerance and the one that has been best studied is butyrate. Certain commensal microbes seem to be especially important. In the small intestine, the important microbes are Lactobacillus, Bifidobacterium, and Prevotella, esp. a particular species, Prevotella histicola, which has been shown to protect against food sensitivities.
15:46 Leaky Gut. If you have leaky gut or increased intestinal permeability, then you can more easily get food antigens across the epithelial lining of the gut and react with the immune cells in the intestinal mucosa. If you have overgrowth of inflammatory type bacteria, such as E. coli, Klebsiella, or Citrobacter, this can cause leaky gut. Certain microbes can modify how antigenic a protein is. Pseudomonas, which is common resident of the small intestine, can break down certain proteins, such as gluten in a way that makes it easier for the gluten to get through the leaky gut. Then the gluten doesn’t break down enough till it is broken into individual amino acids, which is the ideal situation, since amino acids usually do not cause immune reactions. It’s the larger proteins that cause immune reactions. This is one of the reasons why hydrochloric acid is so important to break down proteins and a lot of people do not have enough hydrochloric acid.
Presented by Tom Fabian, PhD, CNTP
Tom is a clinical laboratory consultant, translational science expert, functional nutrition practitioner, educator, and speaker. He is a former biomedical research scientist with deep expertise in the role of the human microbiome in health, chronic disease, and aging. As a leading expert in translational applications of microbiome research in functional medicine and integrative health settings, Tom’s primary focus is on providing educational resources and consulting services for practitioners, and consulting and advisory services for clinical testing laboratories. On a limited basis, he also works with individual clients to improve gastrointestinal health and optimize healthspan.