Influence of gut microbiota on autoimmunity: A narrative review

Abstract

Gut microbiota consists a majority of bacteriodetes, firmicutes, actinobacteria, proteobacteria, fusobacteria, verrucomicrobiota which has evolved a long way alongside humans where it helps in digestion and even other complex functions which include development of gut lymphoid tissue, vitamin synthesis, polarization of specific immune responses, prevention of colonization by pathobionts. Innate and adaptive immunity has been set in the body in contrast to gut microbiota involving helper T cells and cytotoxic cells along with immunoglobulins. Hence immunomodulatory action of gut microbiota is already been studied and explained along with mast cell degranulation. A few factors like age, diet, antibiotics, and others shape normal gut flora into dysbiosis possibly through translocation of microbes, molecular mimicry, and altered metabolite production bringing unfavoured immunological actions like imbalance in helper T cells and improper gut permeability in the body causing, autoimmunity. Changes in microbes from phylum like bacteriodetes, firmicutes, actinobacteria, and proteobacteria bring the changes that lead to various autoimmune diseases like multiple sclerosis, type 1 diabetes mellitus, rheumatoid arthritis etc. This review explains the possible mechanisms along with causes leading to autoimmunity.