Epithelial barrier theory claims the origin of several allergic and chronic noncommunicable diseases is due to local inflammation that propagates systemically and damages epithelial barrier layers.
I found a paper that claims modern environmental exposures compromise skin and mucosal surfaces, initiating local inflammation that propagates systemically, leading to damaged epithelial barriers, and immune responses to the microbiome.
I've been circling similar ideas in this subreddit. Mainly involving a deficiency in epithelial and myelin protective butyrate. However, a viscous cycle of inflammation originating from any source could be responsible for barrier layer damage with and without specific deficiencies.
This paper is sponsored by special interests, including several companies selling commercial probiotics and prebiotics. That can be a source of skepticism. Still, there is a lot of information in the paper and its citations, and little mention of probiotics and prebiotics.
Recent research from ME/CFS teams demonstrate bacterial endotoxins can trigger immune responses that lead to fatigue. I have to assume that the primary way these toxins get to immune cells is by crossing barrier layers. So, this epithelial barrier theory isn't without evidence. Even if you are skeptical about its sponsors, it might be worth a read.
Posted Jan 3, 2026, 5:59 AM UTC