Glutamine Improves Intestinal Barrier Function in Experimental Biliary Obstruction

Abstract

Objective: To determine the effects of enteral administration of glutamine on intestinal barrier function in experimental biliary obstruction. Background: Extrahepatic biliary obstruction is associated with the failure of intestinal barrier function, allowing bacteria and other substances from the intestine to enter the circulation and initiate a systemic inflammatory response, causing impairment of multiple organs. The amino acid glutamine has been shown to improve intestinal barrier function in other conditions, but its effects in biliary obstruction have not been fully examined. Methods: This study examined the effects of enteral administration of glutamine on intestinal permeability and on bacterial translocation from the intestine in a rodent model of biliary obstruction. Results: Glutamine was shown to reduce intestinal permeability measured as percentage excretion of ¹⁴C 7 days after biliary obstruction (0.35 ± 0.03 vs. 0.56 ± 0.085% in controls, p = 0.028), and glutamine administration was also associated with a decreased incidence of bacterial translocation to extra-intestinal sites (p = 0.03). Radiolabelled bacterial studies also demonstrated reduced translocation of bacterial fragments to extra-intestinal sites in glutamine-treated animals (p = 0.01). There was also some evidence of decreased exposure to endotoxin, reduced systemic inflammation and increased bacterial killing by the immune system in glutamine-treated animals. Conclusions: Glutamine modulates intestinal permeability and reduces bacterial translocation in an animal model of experimental biliary obstruction and may increase bacterial killing by the immune system.