The influence of intestinal microbiota on the development of rheumatoid arthritis: key microorganisms and their role in the regulation of the immune response

Abstract

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by joint inflammation, pain, and systemic manifestations. Increasing evidence suggests a strong link between intestinal microbiota and the pathogenesis of RA. Dysbiosis contributes to immune dysfunction by altering intestinal permeability, modulating sex hormones, and affecting regulatory and effector T-cell balance. Specific microorganisms play a dual role in disease progression and protection: Prevotella copri and Collinsella species are associated with early RA, whereas Bacteroides fragilis, Clostridium, and Bifidobacterium longum demonstrate protective immunomodulatory effects. The microbiota-driven regulation of cytokines such as IL-17, TNF-α, and RANKL underscores its significance in bone resorption and systemic inflammation. These findings highlight the potential of targeting gut microbiota as a preventive and therapeutic strategy in RA.