Combination of Dietary Fibers From Different Food Origins as a Treatment for Adults With Functional Constipation: A Randomized Clinical Trial

ABSTRACT

Laxatives are the primary treatment for functional constipation (FC), but they are not always effective and well‐tolerated. Dietary fiber can represent a valid alternative. This study aimed to determine whether combining dietary fibers from different origins could be a valuable strategy for FC. Thus, the efficacy of a fiber‐based formulation (MNS‐36), composed of resistant dextrin from wheat starch ( Triticum aestivum L.), pectin, and insoluble fibers from Citrus spp., and oat fibers ( Avena sativa L.) was tested in a monocentric, double‐blind, randomized, placebo‐controlled clinical trial with 54 adults with FC. Participants received two sachets of MNS‐36 or a placebo daily for 28 days, with weekly visits and a follow‐up. Compared to the placebo group, bowel movements, used as the primary outcome of the study, increased significantly between baseline and week 4 ( β  = 2.43 ± 0.23, p  < 0.001). Similarly, Bristol Stool Form Scale scores significantly improved in the treatment group ( p  < 0.001), being normalized from week 2 onwards ( p  ≤ 0.008). In the treatment group, significant reductions were also observed in abdominal bloating ( β  = 1.21 ± 0.17, p  < 0.001), abdominal distension ( β  = 1.66 ± 0.18, p  < 0.001), heaviness ( β  = 1.39 ± 0.21, p  < 0.001), and flatulence ( β  = 1.51 ± 0.26, p  < 0.001), whereas abdominal pain did not differ significantly between groups. No adverse events were reported, and treatment adherence was high. These findings highlight the efficacy of combining soluble and insoluble fibers from different food origins in improving gut function, addressing both symptoms and tolerability, and underscore this strategy as a natural alternative approach to laxatives for managing FC.