Effectiveness of a Multispecies Synbiotic on Functional Constipation: A Randomized Controlled Trial

Background: Changes in the intestinal microbial flora may contribute to the occurrence and intensification of functional constipation (FC). Probiotics have shown promise as a potential alternative treatment for constipation. Objectives: The main goal of this study is to assess the effects of an Iranian multispecies synbiotic supplement on FC. Methods: This randomized controlled trial (RCT) recruited 115 adult patients who met the Rome IV criteria for FC after fulfilling the inclusion criteria. They were randomly assigned to receive either psyllium (n = 57) or psyllium plus synbiotic (n = 58) daily for 4 weeks. The treatment response was evaluated based on changes in stool consistency (based on the Bristol scale), bloating severity, and constipation intensity (based on the Wexner Constipation Scoring System), and those with a partial to excellent response were considered treatment successes. Results: The two groups did not differ in terms of sex, age, and BMI. The downward trend of stool consistency, bloating, as well as, constipation intensity was significant after 2 weeks of synbiotic-containing intervention. Treatment success after 4 weeks was 75.44% in the synbiotic group, compared to 30.91% in the psyllium-alone group (P < 0.001), indicating the superior efficiency of the synbiotic. Neither treatment exhibited adverse effects (P = 0.924), although psyllium was found to be less tolerable than the synbiotic (P = 0.026). Conclusions: Multispecies synbiotic intake for 4 weeks may be a promising treatment option for FC, given its striking favorable effects on constipation severity, safety, and tolerability.