Colon to Rectum
Aliment Pharmacol Ther. 2022;56(9):1318–27
Randomized controlled trial: Effects of gluten-free diet on symptoms and the gut microenvironment in irritable bowel syndrome
Background: A gluten-free diet (GFD) reduces symptoms in some patients with irritable bowel syndrome (IBS) through unclear mechanisms.
Aims: To assess the effects of gluten-free versus gluten-containing diet on symptoms and the gut microenvironment, and to identify predictors of response to the GFD in IBS
Methods: 20 patients with IBS and 18 healthy controls followed a GFD during two 14-day intervention periods where they sprinkled either gluten (14 g/day) or rice flour powder over their meals. Primary outcomes included effects of the interventions on IBS symptoms (IBS symptom severity score, IBS-SSS) and bowel habits. Secondary outcomes included effects of GFD on fecal microbiota and metabolite profile.
Results: IBS symptoms improved during the gluten-free (p = 0.02), but not the gluten-containing period, with no difference between the interventions. IBS patients reported fewer loose stools during the gluten-free intervention (p = 0.01). Patients with IBS and healthy controls presented distinct metabolite profiles based on the effects of the GFD (p < 0.001). True responders (reduced IBS-SSS by ≥ 50 solely after gluten-free period) and non-responders were discriminated based on the effects of the GFD on the microbiota (p < 0.01) and metabolite profiles (p < 0.001). The response to the GFD could be predicted by the metabolite profile before the intervention (p < 0.001).
Conclusions: A gluten-free diet (GFD) may influence symptoms in a subset of patients with irritable bowel syndrome, with a particular effect on bowel habits. A GFD seems to impact the gut microenvironment. Responsiveness to the GFD may be predicted by the metabolite profile.