Steven D. Townsend Department of Chemistry Vanderbilt University Thursday, November 29 2018, 11am Chemistry Building, Room 400 Organic Seminar As bacteria play essential roles in maintaining human health and contributing to human illness, the establishment and maintenance of a symbiotic microbiome is key to metabolic, immunologic, and hormonal homeostasis. At no time is this more important than during infancy which is a critical period of growth and immune system development. Human milk contributes substantially to the establishment of a healthy gut microbiome in breastfed infants by providing an inoculum of >400 symbiotic and commensal bacterial species and supplying components that promote or suppress the growth of select bacteria. Yet, our mechanistic understanding of how a host responds to or modulates a bacterial challenge is deficient. This talk will focus on describing how HMOs maintain microbiome homeostasis over dysbiosis.