SLE is a complex and heterogeneous disease in which both genetic and environmental factors are contributory. While current attention is heavily focused on genome wide association studies, emerging data suggest that our own bacterial flora, and in particular the gut microbiome, are contributors to a range of autoimmune and inflammatory diseases. The gut microbiome refers to the vast collection of symbiotic microorganisms in the human gastrointestinal system and their collective interacting genomes, which perform numerous key biochemical functions for the host. Accordingly, our research project will investigate the hypothesis that disease onset and clinical flares in SLE are associated with preferential representation (or absence) of certain gut microbial species. We will also examine whether the expression of the interferon signature, which is found in many adult SLE patients, is linked to specific gut microbial species. Together, our studies will provide the foundation for the development and testing of new hypotheses regarding the roles of the microbiota in lupus pathogenesis.