Glutamine may not be useful for induction of remission in Crohn's disease
Available evidence on the efficacy and safety of glutamine for inducing remission in patients with Crohn’s disease is insufficient, according to a recent Cochrane review, leading researchers to call for adequately powered randomized controlled trials.
“Considering that glutamine may have positive nutritional, metabolic and immunologic benefits with respect to [CD], it has been trialed for the treatment of people with the disease,” the researchers wrote. “The aim of this systematic review is to summarize the current evidence on the use of glutamine for induction of remission in [CD].”
Relevant literature was searched through Nov. 15, 2015, and ultimately two small randomized controlled trials involving 42 patients were included in the review.
The first was a double blind trial performed at a single center in the United Kingdom in which 18 patients with active CD younger than 16 years were randomly assigned standard polymeric diet with low glutamine content (4% amino acid composition) or a glutamine-enriched polymeric diet (42% amino acid composition) for 4 weeks as their primary therapy. If the diet could not be consumed orally it was administered via nasogastric tube. Clinical remission at 4 weeks served as the primary outcome.
The second trial, performed at a single center in Germany, involved 24 adults with acute exacerbation of inflammatory bowel disease (19 with Crohn’s) who were being considered for total parenteral nutrition. Participants received 0.3 g/kg per day alanyl-glutamine added to a standard amino-acid solution or a standard amino-acid solution without glutamine. Researchers, nurses, physicians and patients were all masked to treatment assignment. Glutamine plasma concentrations and intestinal permeability after 1 week served as the primary outcomes.
In the pediatric study, there was no significant difference in clinical remission at 4 weeks, with 44% of the glutamine group achieving remission vs. 56% of controls (RR = 0.8; 95% CI, 0.31-2.04). However, the researchers determined “the overall quality of evidence for this outcome was low due to serious imprecision.”
Both studies showed no significant changes in intestinal permeability between groups. Data on endoscopic remission, clinical response, quality of life and growth in children were not reported, and adverse events were not well documented. However, there were no serious adverse events in the pediatric study, and in the adult study, three central catheter infections with positive blood cultures occurred in the glutamine group vs. none in controls (RR = 7; 95% CI, 0.4-122.44).
“Currently there is insufficient evidence to allow firm conclusions regarding the efficacy and safety of glutamine for induction of remission in [CD]. Data from two small studies suggest that glutamine supplementation may not be beneficial in active [CD], but these results need to be interpreted with caution as they are based on small numbers of patients,” the researchers wrote. “This review highlights the need for high-quality, adequately powered randomized controlled trials to investigate the efficacy and safety of glutamine for induction of remission in [CD].” – by Adam Leitenberger
Disclosure: One of the researchers reports receiving travel grants from Abbot Nutrition, Biogai, Clinova, Danone, Ferring, Tillotts, Vifor and Warner Chilcott.