Dr. Phillip Tarr is the Melvin E. Carnahan Professor of Pediatrics, and Director of the Division of Pediatric Gastroenterology, Hepatology, and Nutrition at Washington University School of Medicine. He co-directs the Pediatrics Pathobiology Research Unit, and is a Professor of Molecular Microbiology. He obtained his MD degree from Yale University School of Medicine in 1980, and completed clinical training in pediatrics, pediatric gastroenterology and pediatric infectious diseases at the University of Washington/Seattle Children’s Hospital, where he remained on the faculty until 2003 when he assumed his present position. Dr. Tarr has had an abiding interest in many different aspects of enteric infections and gut microbiology, with a focus on pediatrics. His chief contributions have been in the field of diarrheagenic Escherichia coli, especially E. coli O157:H7. His work has helped delineate the epidemiology, pathophysiology, and medical management of illnesses caused by this pathogen. He has long advocated the role of accurate and thorough enteric diagnostics as a mainstay of clinical care. His current research is centered on the role of the gut microbiome in childhood development and growth. The diseases he studies include necrotizing enterocolitis, tropical enteropathy, and inflammatory bowel diseases.