Oral glutamine supplementation in Inflammatory Bowel Disease patients: Quality of life matters

Abstract

INTRODUCTION: Ulcerative colitis (UC) and Crohn's disease (CD) are inflammatory bowel diseases (IBD), which mostly appear in a relapsing remitting form. During acute episodes, patients' quality of life is often highly deteriorated, as bloody diarrhea and abdominal pain are common symptoms. Despite improvements in diagnostic and therapeutic strategies, the treatment of IBD is still unsatisfactory, as conventional therapy to induce and maintain remission mainly works in a symptomatic style, merely suppressing the immune response. Within nutritional therapy, L-glutamine (GLN) is a promising candidate to exert a protective function on altered intestinal mucosa. AIMS & METHODS: In this randomized, double-blind, placebo-controlled pilot study, we investigated the effects of an 8-week application of a GLN-containing oral nutrition supplement in 22 corticosteroid-treated IBD patients (8 UC, 14 CD) with moderate and severe inflammatory episodes, on health-related quality of life, judged by the intestinal bowel disease questionnaire (IBDQ, McMaster University, Canada) and on disease activity, measured by the Crohn's disease activity index (CDAI) and the colitis activity index (CAI), respectively. Patients received either an oral nutritional supplement containing 10 grams of GLN, vitamins, electrolytes and trace elements or an equal composition devoid of GLN (placebo). IBDQ, CAI, CDAI, and the amount of required corticosteroids were assessed at baseline, and after 2, 4, 6, 8, and 12 weeks of investigational product administration. For group comparisons of metric and ordinal variables the Mann-Whitney-U-test was used. All tests are two-tailed with a confidence level of 95%; no adjustment for the type-I-error was made. RESULTS: 18 of the 22 recruited patients completed the study according to the protocol. Although there were no marked group differences in the overall IBDQ-score, the bowel sub-score, reflecting bowel specific issues, improved more in the GLN group than in the placebo group (after 8 weeks: p=.032) .This observation was similar for UC and CD patients. Presumably due to the low numbers of patients, the clear tendencies towards a GLN-specific IBDQ bowel sub-score improvement could be reproduced only partially in the disease-specific scores (CDAI, CAI). Regarding corticosteroid medication during GLN-application, no relevant differences were seen in both, duration and quantity of corticosteroid-usage. CONCLUSION: The application of GLN in IBD-patients tends to improve the healthrelated quality of life, and might exert beneficial effects on disease activity. However, as the results of our study are merely descriptive, follow-up studies with higher case numbers and a confirmatory design are needed