Project Summary: The Gnotobiotics, Microbiology and Metagenomics Core (Core D), supports investigators studying functional roles of the microbiota in health and disease. Core D has supported >100 groups interested in evaluating mechanisms of action by which the host’s microbiota affects host physiologic and pathophysiologic processes. Our resources include a Microbiology Unit for microbiologic culturing, phenotyping, analysis of primary samples for microbial metabolite profiles, and develop defined consortia for functional studies, a Clinical Lab (CLIA) Unit to support microbiome-focused clinical trials, a Molecular Unit for sequence-based analyses, a Gnotobiotic (germfree) mouse facility for in vivo studies in animal models, a Metabolic Unit to support mouse metabolic cage, body composition and metabolism studies, and a Computational Unit which undertakes novel algorithmic development to evaluate longitudinal dynamics of the microbiota and assist users in experimental design for host-microbiota studies. Core D provides support to multiple academic centers in the greater Boston area.