ELEMENTAL DIET AND IV-TPN-INDUCED BACTERIAL TRANSLOCATION IS ASSOCIATED WITH LOSS OF INTESTINAL MUCOSAL BARRIER FUNCTION AGAINST BACTERIA

Objective The goal of the current study was to directly assess the rol e of loss of mucosal barrier function in nutritionally induced bacteri al translocation. Background Parenteral and certain elemental enteral diets have been shown to promote bacterial translocation. The mechanis ms underlying this observation, especially the question of whether nut ritionally induced bacterial translocation is primarily related to los s of intestinal barrier function, versus an impaired immune system, re main to be fully elucidated. Methods Bacterial translocation was measu red in vivo, ileal mucosal membranes were harvested, and their electro physiologic properties and barrier function were measured ex vivo in t he Ussing chamber system 7 days after receiving total parenteral nutri tion solution parenterally (IV-TPN) or enterally (elemental diet). Cho w-fed rats served as control subjects. Results The incidence of bacter ial translocation was significantly increased both to the mesenteric l ymph nodes in vivo and across the in vitro Ussing chamber-mounted ilea l mucosal membranes of the elemental diet-fed and IV-TPN-fed rats. The magnitude of Escherichia coli and phenol red transmucosal passage in the Ussing chamber was significantly higher in the IV-TPN-fed rats tha n in the elemental diet-fed or chow-fed animals. The potential differe nces across the ileal membrane were similar between the three groups a t all time points. However, the specific resistances of the ileal memb ranes of the IV-TPN and elemental diet groups were significantly less than the chow-fed animals, indicating increased membrane permeability. Conclusions Loss of intestinal barrier function plays a major role in nutritionally induced bacterial translocation, and the loss of mucosa l barrier function to both E. coil and phenol red appeared greater in the IV-TPN than the elemental diet-fed rats.