Mounting evidence suggests that particular aspects of human health and disease may be attributable to the trillions of microbes that inhabit our gastrointestinal tract, collectively referred to as the gut microbiota. As part of the mini-symposium entitled "Manipulating the Gut Microbiome for Human Health," Drs. McCormick and Blanchard introduce the symposium, which will offer session lectures and a follow-up interactive, discussion-based workshop on topics related to attempts to manipulate the gut microbiota to improve health.