Dietary fibre blend improves gut health in patients with irritable bowel syndrome following a low FODMAP diet: a randomised, double-blind control trial.

PURPOSE: A diet low in FODMAP may negatively affect the gut microbiota of some Irritable Bowel Syndrome (IBS) patients, despite alleviating symptoms. This pilot study comprehensively explores the effects of a 3-week ur gut® supplementation on gut microbiota, gut health, dietary intake, sleep, mental health and quality of life (QOL) in individuals with IBS following a low FODMAP diet. METHODS: Adult participants (n = 26, 3 males) completed a randomised, double-blind controlled study. Participants were provided with either ur gut® (n = 13) or placebo (n = 13) for 3 weeks after a 1-week baseline. At baseline and end of intervention, blood, 24-h faecal samples and 3-day weighed-food diaries were collected. Validated questionnaires were used to evaluate mental health, sleep, QOL and gut symptoms. Participants reported daily IBS symptoms and wore a wrist-based actigraphy to capture daily sleep. RESULTS: During the intervention, both groups maintained baseline stable gut symptoms and sleep patterns. After the intervention, the ur gut® group had lower energy (P < 0.05) and protein (P < 0.01) intake compared to the placebo group, and increased resistant starch intake (P < 0.001) compared to baseline. Changes in overall genus-level gut microbiota composition (P < 0.01), including Ruminococcus E (5.5-fold increase, P < 0.01), were observed. ur gut® improved GI-specific anxiety (P = 0.01) and sexual subscale of QOL (P < 0.05). CONCLUSION: Compared with placebo, ur gut® increased dietary fibre intake, improved gut microbiota and gastrointestinal-specific anxiety without negatively impacting sleep, despite no changes observed in faecal and blood biomarkers. This provides a dietary strategy to support gut health without compromising symptom control in IBS. Australia and New Zealand Clinical Trial Registry http://www.anzctr.org.au/ , ACTRN12620000032954.