ObjectiveEnteral glutamine supplements have been shown to reduce infectious morbidity in trauma patients, but their effect on burn patients is not known. The objective of this study was to measure the impact of enteral glutamine supplementation on infectious morbidity, length of care, and the immune system in burn patients.DesignDouble-blinded, randomized clinical trial.SettingBurn center.PatientsForty-five adults with severe burns.InterventionsPatients were randomized to receive either glutamine or an isonitrogenous control mixture until complete healing occurred. Length of care, incidence of positive blood culture, and mortality were recorded. Phagocytosis by circulating polymorphonuclear cells was measured every 3 days.Measurements and Main ResultsPatient characteristics were similar in both groups. Four patients were excluded from the analysis, because three of them died within 72 hrs and the fourth could not receive enteral nutrition and amino acid supplements for the first 10 days. Of the remaining 41 patients, length of care in the survivors was not different between groups (0.9 vs. 1.0 days/percent total body surface area for glutamine vs. control, respectively), positive blood culture was three times more frequent in control than in glutamine treatment (4.3 vs. 1.2 days/patient,p< .05), andPseudomonas aeruginosawas detected in six patients on control and zero on glutamine (p< .05). Phagocytosis by polymorphonuclear cells was not different between groups. Mortality rate was significantly lower in glutamine than in control: intention to treat, two vs. 12 (p< .05); per protocol analysis, zero vs. eight (p< .01).ConclusionsEnteral glutamine supplementation in adult burn patients reduces blood infection by a factor of three, prevents bacteremia withP. aeruginosa, and may decrease mortality rate. It has no effect on level of consciousness and does not appear to influence phagocytosis by circulating polymorphonuclear cells.