Intestinal Permeation and Gastrointestinal DiseaseDeMeo, Mark T.; Mutlu, Ece A.; Keshavarzian, Ali; Tobin, Mary C.Journal of Clinical Gastroenterology: April 2002 - Volume 34 - Issue 4 - p 385-396 Alimentary Tract: Clinical Reviews: The Small Intestine and Nutrition Abstract Author Information The gastrointestinal tract constitutes one of the largest sites of exposure to the outside environment. The function of the gastrointestinal tract in monitoring and sealing the host interior from intruders is called the gut barrier. A variety of specific and nonspecific mechanisms are in operation to establish the host barrier; these include luminal mechanisms and digestive enzymes, the epithelial cells together with tight junctions in between them, and the gut immune system. Disruptions in the gut barrier follow injury from various causes including nonsteroidal anti-inflammatory drugs and oxidant stress, and involve mechanisms such as adenosine triphosphate depletion and damage to epithelial cell cytoskeletons that regulate tight junctions. Ample evidence links gut barrier dysfunction to multiorgan system failure in sepsis and immune dysregulation. Additionally, contribution of gut barrier dysfunction to gastrointestinal disease is an evolving concept and is the focus of this review. An overview of the evidence for the role of gut barrier dysfunction in disorders such as Crohn's disease, celiac disease, food allergy, acute pancreatitis, non-alcoholic fatty liver disease, and alcoholic liver disease is provided, together with critical insight into the implications of this evidence as a primary disease mechanism. From the Divisions of Gastroenterology and Nutrition (M.T.D., E.A.M., A.K.) and of Allergy and Immunology (M.C.T.), Rush University, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, U.S.A. Address correspondence and reprint requests to Dr. Mark T. DeMeo, Rush-Presbyterian-St. Luke's Medical Center, Professional Building, 1725 West Harrison, Suite 206, Chicago, IL 60612, U.S.A. E-mail: firstname.lastname@example.org © 2002 Lippincott Williams & Wilkins, Inc.