Randomized clinical trial: Effects of Aloe barbadensis Mill. extract on symptoms, fecal microbiota and fecal metabolite profiles in patients with irritable bowel syndrome.

Abstract

Aloe barbadensis Mill. (Aloe) with potential prebiotic effects has been suggested to reduce symptoms in patients with irritable bowel syndrome (IBS). We therefore aimed to determine the effects of an Aloe extract on symptoms of IBS, and evaluate whether effects may be mediated by fecal microbiota and metabolites in a randomized, double-blind, controlled trial. Patient with IBS diagnosed according to the ROME III criteria (all subtypes), received Aloe or control treatment (inulin) for 4weeks. IBS Symptom Severity Score (IBS-SSS) was assessed, and fecal samples collected before and at end of treatment. Fecal microbiota composition and metabolomic profile were determined. In total, 160 IBS patients completed the study. The overall severity of IBS symptoms was reduced in both Aloe and control treatment groups (P<.001, both groups, comparing baseline vs end of treatment), without difference between groups (P=.62). The frequency of responders (IBS-SSS reduction≥50) did not differ between Aloe treatment (n=33, 39%) and control (n=34, 45%) (P=.49). However, fecal microbiota and metabolite profiles differed between Aloe, but not control treatment responders and non-responders both before and after treatment. In a mixed group of IBS patients, Aloe was not superior to control treatment, although it showed potential to reduce IBS symptom severity in subsets of IBS patients which could be predicted by fecal microbiota and metabolite profiles. ClinicalTrials.gov no: NCT01400048.