The role of enteric microflora in inflammatory bowel disease

Enteric microflora play an important role in the development and course of ulcerative colitis (UC) and Crohn’s disease (CD), the two major forms of inflammatory bowel disease (IBD). No infectious agent has been proved as a causative factor of IBD, although in numerous studies Mycobacterium avium sub-species paratuberculosis has been proposed to be an inciting agent of CD. Indigenous intestinal microorganisms have a significant impact on normal host physiology. In normal conditions commensal bacteria remain in a state of homeostasis with the gastrointestinal immunological system. Disturbances of protective functions or regulatory mechanisms can lead to inappropriate activation of the mu-cosal immune system and inflammation resulting in tissue injury. The composition and function of enteric microflora in patients with IBD reveal substantial changes as compared to healthy persons. Therapeutic manipulation of intestinal microorganisms offers great potential for the treatment of active disease and maintenance of remission in IBD.