Background More effective treatments are needed for patients with postinfectious, diarrhoea-predominant, irritable bowel syndrome (IBS-D). Accordingly, we conducted a randomised, double-blind, placebo-controlled, 8-week-long trial to assess the efficacy and safety of oral glutamine therapy in patients who developed IBS-D with increased intestinal permeability following an enteric infection.
Methods Eligible adults were randomised to glutamine (5 g/t.i.d.) or placebo for 8 weeks. The primary end point was a reduction of ≥50 points on the Irritable Bowel Syndrome Severity Scoring System (IBS-SS). Secondary endpoints included: raw IBS-SS scores, changes in daily bowel movement frequency, stool form (Bristol Stool Scale) and intestinal permeability.
Results Fifty-four glutamine and 52 placebo subjects completed the 8-week study. The primary endpoint occurred in 43 (79.6%) in the glutamine group and 3 (5.8%) in the placebo group (a 14-fold difference). Glutamine also reduced all secondary endpoint means: IBS-SS score at 8 weeks (301 vs 181, p<0.0001), daily bowel movement frequency (5.4 vs 2.9±1.0, p<0.0001), Bristol Stool Scale (6.5 vs 3.9, p<0.0001) and intestinal permeability (0.11 vs 0.05; p<0.0001). ‘Intestinal hyperpermeability’ (elevated urinary lactulose/mannitol ratios) was normalised in the glutamine but not the control group. Adverse events and rates of study-drug discontinuation were low and similar in the two groups. No serious adverse events were observed.
Conclusions In patients with IBS-D with intestinal hyperpermeability following an enteric infection, oral dietary glutamine supplements dramatically and safely reduced all major IBS-related endpoints. Large randomised clinical trials (RCTs) should now be done to validate these findings, assess quality of life benefits and explore pharmacological mechanisms.
Trial registration number NCT 1414244; Results.
- irritable bowel syndrome
- enteric infections
- intestinal permeability
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Contributors All authors contributed to the design and draft of the paper.
Funding This study was supported by the National Center for Complementary and Integrative Health (AT005291); National Institute of Diabetes and Digestive and Kidney Diseases (DK099052) and the Department of Veterans Affairs (CX001477-01). Supported in part by 1 U54 GM104940 from the National Institute of General Medical Sciences of the National Institutes of Health, which funds the Louisiana Clinical and Translational Science Center. ClinicalTrials.gov number, NCT1414244.
Competing interests None declared.
Patient consent Obtained.
Ethics approval Institutional Review Board.
Provenance and peer review Not commissioned; externally peer reviewed.
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