We investigated the effect of a glutamine-enriched enteral diet on intestinal permeability and infectious morbidity and mortality in critically ill patients who developed systemic inflammatory response syndrome after an acute event. Eleven intensive care units in tertiary-care hospitals participated in a prospective, randomized, single blind, multicenter trial. Eighty-four patients with systemic inflammatory response syndrome of any etiology were randomly allocated to receive a glutamine-enriched enteral diet or a control diet without glutamine.Most patients received the planned caloric intake. The number of infected patients was smaller in the glutamine group than in the control group (11 versus 17 patients, P < 0.05), with a relative risk of 0.5 (95% confidence interval = 0.3-0.9). The most frequent infection was nosocomial pneumonia, with 11 (33%) patients in the control group and 6 (14%) in the glutamine group. There were no differences with respect to other infections, mortality, or length of stay. Intestinal permeability as assessed by the lactulose-mannitol test was unchanged in both groups.Glutamine-enriched enteral diets can decrease nosocomial infections in patients with systemic inflammatory response syndrome.