Double-blind randomized controlled trial of glutamine-enriched polymeric diet in the treatment of active Crohn's disease

Background: Glutamine is traditionally considered a nonessential amino acid but may be conditionally essential in patients with catabolic conditions. Glutamine-supplemented foods in these patients have been shown to prevent d eterioration of gut permeability, protect against the development of intest inal mucosal atrophy, and improve nitrogen balance. Animal models of inflam matory bowel disease suggest that glutamine-enriched enteral diets may lead to less severe intestinal damage, less weight loss, improved nitrogen bala nce, and reduced disease activity. The purpose of the current study was to compare the efficacy of a glutamine-enriched polymeric diet with a standard low-glutamine polymeric diet in the treatment of active Crohn's disease. Methods: Eighteen children with active Crohn's disease were randomly assign ed to receive a 4-week course of either a standard polymeric diet with a lo w glutamine content (4% of amino acid composition; group S) or a glutamine- enriched polymeric diet (42% of amino acid composition; Group G). The two d iets were isocaloric and isonitrogenous with an identical essential amino a cid profile. Remission rates were analysed on an intent-to-treat basis. Cha nges in clinical and laboratory parameters of disease activity were also co mpared after 4 weeks of nutritional treatment. Results: Two of the children, both in group G, were withdrawn from the tria l because of nontolerance of the diet. There was no difference between the two groups in proportion of patients achieving remission (intent-to-treat b asis): 5 (55.5%) of 9 in soup S versus 4 (44.4%) of 9 in group G (I, = 0.5) . Improvement in mean paediatric Crohn's disease activity index (PCDAI) was significantly more in soup S (I, = 0.002) but changes' in orosomucoid leve l, platelet count, and weight were nor different between the groups. Conclusions: The findings suggest that a glutamine-enriched polymeric diet offers no advantage over a standard low-glutamine polymeric diet in the tre atment of active Crohn's disease. Rather, it appears to be less effective i n improving PCDAI. The reported beneficial effects of glutamine seen in man y catabolic states must be viewed with caution when extrapolating to the ma nagement of Crohn's disease. (C) 2000 Lippincott Williams & Wilkins, Inc.