Epithelial barrier hypothesis and the development of allergic and autoimmune diseases

Abstract The “epithelial barrier hypothesis” proposes that genetic predisposition to epithelial damage, exposure various barrier–damaging agents and chronic periepithelial inflammation are responsible for the development of allergic autoimmune diseases. Particularly, introduction more than 200,000 new chemicals our daily lives since 1960s has played a major role in pandemic increase these constitutes first line physical, chemical, immunological defence against external factors. A leaky initiates translocation microbiome from surface affected tissues interepithelial even deeper subepithelial areas. In with defective barrier, colonization opportunistic pathogens, decreased microbiota biodiversity, local inflammation, impaired regeneration remodelling takes place. dysregulated immune response commensals pathogens starts. Migration inflammatory cells other their contribution tissue injury key events exacerbation many Understanding underlying factors affect integrity barriers is essential find preventive measures or effective treatments restore its function. aim this review assess origins diseases within framework hypothesis.