Tehran University of Medical Sciences Acta Biochimica Iranica 0001-5261 2026 4 2026 06 25 53 62 Ali Abedian Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Siavash Amiri Department of Clinical Biochemistry, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran Maryam Nobakht Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran. Faezeh Talari Student Research Committee, Kashan University of Medical Sciences, Kashan, Iran. Esmat Aghadavood Research Center for Biochemistry and Nutrition in Metabolic Diseases, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran. Mohamad Esmaeil Shahabodin 2Research Center for Biochemistry and Nutrition in Metabolic Diseases, Kashan University of Medical Sciences, Kashan, Iran 2026 02 26 2026 05 17 Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by persistent synovial inflammation, progressive joint destruction, and systemic complications. Although genetic susceptibility and environmental factors contribute to disease development, the precise mechanisms underlying RA pathogenesis remain incompletely understood. Increasing evidence suggests that the gut microbiota plays a critical role in regulating host immune responses and maintaining immune homeostasis. Alterations in the composition and function of gut microbial communities (dysbiosis) have been associated with immune dysregulation and the development of autoimmune diseases, including RA. Recent studies indicate that modulation of the gut microbiome through probiotics, prebiotics, dietary interventions, and microbiota-targeted therapies may alleviate inflammation and improve clinical outcomes in RA patients. This review summarizes the current understanding of RA pathogenesis, highlights the role of gut microbiota in immune regulation, and discusses the therapeutic potential of microbiome-based interventions in the management of RA. https://abi.tums.ac.ir/index.php/abi/article/view/183 https://abi.tums.ac.ir/index.php/abi/article/download/183/137