Postbiotics and the gut–joint axis: emerging therapeutic strategies in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by systemic inflammation and progressive joint destruction. Recent evidence implicates the gut microbiota as a critical factor in RA pathogenesis through mechanisms such as intestinal barrier disruption, molecular mimicry, and immune modulation. This review examines the emerging role of gut dysbiosis in RA development and progression, highlighting how imbalances in microbial communities may trigger or exacerbate autoimmune responses via increased intestinal permeability, shared epitopes, and Th17/Treg cell dysregulation. Particular attention is given to the therapeutic potential of postbiotics as novel interventions in RA. Postbiotics, including short-chain fatty acids (SCFAs), exopolysaccharides, and microbial-derived vitamins, exhibit anti-inflammatory, immunoregulatory, and barrier-protective effects with favorable safety profiles. These compounds influence immune tolerance, modulate cytokine production, and reinforce gut integrity, offering promising microbiome-targeted strategies for managing RA. This review advocates for the continued investigation of postbiotics as adjunct or alternative therapeutics in autoimmune diseases, especially RA.