Human Milk Oligosaccharides Support Normal Bowel Function and Improve Symptoms of Irritable Bowel Syndrome: A Multicenter, Open-Label Trial

INTRODUCTION: Treatment options for irritable bowel syndrome (IBS) are limited, causing many patients to remain symptomatic. This study assessed the potential of human milk oligosaccharides (HMOs) to normalize bowel habits. Secondary outcomes included IBS severity and health-related quality of life. METHODS: This multicenter, open-label trial recruited patients with IBS from 17 sites across the United States. Patients received daily orally administrated 5-g intervention of the HMOs 2'-fucosyllactose and lacto-N-neotetraose in a 4:1 mix. Bowel habits, IBS symptoms, and quality of life were assessed at baseline and every 4 weeks during the 12-week intervention. RESULTS: A total of 317 patients (70.7% women; mean age of 44.0 years, range 18–93 years) received the trial product, and 245 patients completed the trial according to protocol. Patients had a significant improvement from baseline to 12 weeks in total percentage of bowel movements with abnormal stool consistency (mean and [95% confidence interval]: 90.7 [88.9–92.9] vs 57.2% [53.9–60.5], P < 0.0001), overall IBS Symptom Severity Score (323 [314–332] vs 144 [133–155], P < 0.0001) and health-rela,ted quality of life (50.4 [48.0–52.8] vs 74.6 [72.3–76.9], P < 0.0001). Improvement was similar across IBS subtypes. Symptoms improved most in the first 4 weeks of intervention. The most common side effects were mild gastrointestinal symptoms such as flatulence, abdominal pain and discomfort, and distension. DISCUSSION: Supplementation with 2 selected HMOs improves IBS symptoms and quality of life without substantial side effects. These promising results suggest that this novel approach to IBS should be confirmed in a randomized, placebo-controlled trial.