Purpose of review: Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown cause. In recent years, with the emergence of microbiome research, changes in the gut microbiota composition have been correlated with a variety of autoimmune disorders, and several mechanisms linking these together have been suggested, including the hygiene theory, immune system activation and hormonal effects. It has therefore been suggested that gut microbiota may play a role in SLE. In this review, we summarize recent findings on the SLE-related microbiota compositions in both humans and rodents. Evidence linking microbiome with SLE opens a new avenue in researching the cause of SLE as well as improved future treatments.
Recent findings: Although two studies found a lower Firmicutes/Bacteroidetes ratio in SLE patients vs. controls, there were inconsistencies regarding significant differences in the abundance of specific genera or species. Studies of mouse disease models have shown some correlations between microbial compositions and disease states, also indicating differences between males and females.
Summary: Current data support an association between microbiota composition and SLE. Further research is needed to fully unravel this connection, potentially shedding light on mechanisms in SLE development and on the female bias of the disease, improving diagnosis and treatment.