The incidence of Inflammatory Bowel Disease is increasing worldwide in lockstep with modernization and worldwide ‘Westernization’ of lifestyles. One of the most important aspects of Westernization for human health is the adoption of a diet high in fat and sugar and low in fiber. Relatively little is known about how dietary sugar specifically affects the incidence and severity of IBD, though increased intake has been associated with disease, and diets low in simple sugars have shown promise in combating IBD in the clinic. Our preliminary data has indicated that a short course of dietary sugar supplementation is sufficient to induce a lethal syndrome characterized by profound intestinal pathology in mice undergoing a common colitis protocol. Additionally we have associated increased sugar in the diet to population shifts in intestinal immune cells. Here we propose to study how sugar mediates changes to the immune system and colon resident bacteria and how they might lead to a breakdown of the intestinal epithelium. At the conclusion of this work we hope to define novel sugar-modified mechanisms of the intestinal immune response with the hope that these will aid in efforts to design diets for IBD patients that will reduce inflammation and disease flares.