The role of the intestinal microbiome in ocular inflammatory disease

Purpose of review: The intestinal commensal microbiota are important in shaping immune cell repertoire and are influenced by host genetics. Because of this intricate interaction, an intestinal dysbiosis has been associated with multiple immune-mediated polygenic diseases. This review summarizes the literature on how alterations in the intestinal microbiota contribute to immune-mediated ocular disease, and how to potentially target the gut microbiome for therapeutic benefit. Recent findings: Several groups have demonstrated the importance of the intestinal microbiome in uveitis pathogenesis. Two groups showed that altering the microbiota with oral antibiotics results in reduced uveitis severity, and another group demonstrated that a commensal bacterial antigen activates retina-specific autoreactive T cells, potentially indicating a commensal trigger for uveitis. We have found that commensal bacterial metabolites, short chain fatty acids, can suppress autoimmune uveitis. Age-related macular degeneration is associated with an intestinal dysbiosis, which can be influenced by genetic risk alleles and age-related eye disease study (AREDS) supplementation. Strategies that might be effective for targeting the intestinal microbiota might involve several approaches, including the use of antibiotics, drugs that supplement beneficial bacterial components or target inflammatory bacterial strains, dietary strategies or microbial transplantation. Summary: The intestinal microbiota are potentially crucial in propagating inflammatory diseases of the eye, and can be targeted for therapeutic benefit.