A new study published Gut assessed the efficacy and safety of oral glutamine therapy in patients who developed irritable bowel syndrome-diarrhea (IBS-D) with increased intestinal permeability following an enteric infection. This was a randomized, double-blinded, placebo-controlled trial, spanning eight weeks, wherein the primary end point was a reduction of ≥ 50 points on the Irritable Bowel Syndrome Severity Scoring System (IBS-SS). Overall 54 glutamine and 52 placebo subjects completed the study. The primary endpoint occurred in 79.6% in the glutamine group and 5.8% in the placebo group. In addition, glutamine reduced IBS-SS score at 8 weeks, daily bowel movement frequency, Bristol Stool Scale, and intestinal permeability. While Intestinal hyperpermeability (elevated urinary lactulose/mannitol ratios) was normalized 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 in either of the subjects. The findings suggested that in patients with IBS-D with intestinal hyperpermeability following an enteric infection, oral dietary glutamine supplements remarkably and safely reduced all major IBS-related endpoints. Large randomized clinical trials were recommended to validate these findings, assess quality of life benefits, and to explore pharmacological mechanisms of these supplements.