There is expanding evidence that colonic health is based on diet and the microenvironment of the colon and its contents. Dr. Stephen O'Keefe, professor of medicine in the division of gastroenterology at the University of Pittsburgh School of Medicine, joins host Dr. Jay Goldstein to discuss the microbiota of the colonic tract. How do these bacteria, many of which are linked to patients' diet and lifestyle, generate byproducts that lead to the health or disease processes of the colon?