Can Probiotic Supplements Improve Outcomes in Rheumatoid Arthritis?

Purpose of Review The purpose of this review is to frame the discussion of the potential use of probiotics for the management of rheumatoid arthritis (RA) in the historical and scientific context linking the human microbiota to the etiology, pathogenesis, and treatment of RA. Given this context, the review then details the clinical trials that have been carried out so far that have tried to address the question. Recent Findings A variety of laboratory and clinical observations link the flora of the oral cavity and lower gastrointestinal tract with citrullination, as well as immunological alterations that may contribute to the risk of developing RA. Clinical trials to date have been small and mostly short term. Summary Statistically significant change in certain disparate clinical endpoints has been reported, but these endpoints have varied from study to study and have been of limited clinical significance. No consistent, robust impact on patient reported, or laboratory outcome measures has emerged from clinical trials so far. There remain theoretical reasons to further investigate the use of probiotics as adjunctive therapies for autoimmune disease, but changes in trial design may be needed to reveal the benefit of this intervention.