The Kasper lab has identified membrane glycosphingolipids from the commensal bacterium Bacteroides fragilis that reduce colonic invariant natural killer T (iNKT) cells – important contributors of inflammatory bowel disease pathogenesis. Exposure to B. fragilis glycosphingolipids at a young age or through administration to mothers during pregnancy protects mice from induced colitis in adulthood. Currently, human milk is the only source of sphingolipids for infants. Infant formula and baby food products containing these unique glycosphingolipids may be used prophylactically in infants and young children to promote long-lasting immune homeostasis in the gut as well as support general early life nutrition requirements. Additionally, formulations for pregnant women may promote long-lasting gut immune homeostasis for their children.