Recent insights into the protective effects of lactic acid bacteria on rheumatoid arthritis

Rheumatoid Arthritis (RA) greatly affects patient's life. Systematic reviews of recent epidemic trend and the pathogenesis of RA are inadequate. Although multiple health benefits of lactic acid bacteria (LAB) were reported, comprehensive reviews addressing the mechanisms by which LAB alleviate RA remain limited. This review systematically examines the epidemiology and pathogenesis of RA, emphasizing the potential modulatory role of LAB in maintaining intestinal homeostasis. Drawing on both animal and clinical evidence, the review critically evaluates the molecular mechanisms by which LAB may alleviate RA, thereby offering a theoretical foundation for microbiota-based therapeutic interventions. Meanwhile, it highlighted the challenges and opportunities of LAB for RA. Genetic predisposition, environmental factors, and immune system dysfunction play very important roles in causing RA. LAB provided numerous advantages and had great potential for improving RA as its ability to regulate intestinal barrier, modulate related enzyme activity, inhibit oxidative damage, restore unbalanced gut microbiota, produce bioactive metabolites, and regulate gut-joint immune axis. In addition, this review advice to screen effective LAB by cell models and metabolites, to determined the optimal intake dose of LAB through dose-effect relationship studies, to promote the understanding of LAB by investigating the mechanism, and to improve the design of the clinical study to improve the lives of RA patients. This will contribute to understanding the epidemiological characteristics, pathogenesis, and treatment of RA, and promote the development of targeted therapeutic RA products such as LAB.