Inflammatory bowel disease

The inflammatory bowel diseases (IBD) are characterized by chronic intestinal inflammation of unknown etiology. There are two main categories of IBD: ulcerative colitis (UC) and Crohns Disease (CD), which are differentiated on the basis of pathologic features (Table 1.) The prevalence in the United States of both forms of IBD appears to be about 200 per 100,000 people (1), and there is geographic variation around the world as well as temporal variation (2). Both forms of IBD can result in substantial impairments in quality of life, with complications including but not limited to malabsorption, intestinal adhesions and perforation, infections and cancer (1). Although the pathogenesis is unclear, factors involving the human intestinal microbiota have long been suspected (3). Indeed, the role of the intestinal microbiota in IBD has been studied in far more depth in this condition than in any other systemic condition. While no solid consensus is observed among the studies, they coincide in the loss of diversity and changes in specific taxa. This chapter will review data on the contents of the microbiota, as well as the relationship between the microbiota and immunity, and the potential for treating IBD through manipulation of the microbiota