Objective: To investigate the clinical efficacy of a multi-strain probiotic product on bowel habits and microbial profile in participants with functional constipation.
Methods: This was a randomized, double-blind, placebo-controlled and parallel-arm study. Altogether 94 otherwise healthy adults aged 18 to 65 years with symptoms of functional constipation were randomized as part of the intention-to-treat population. The participants received a placebo or the probiotic product (1.5 × 1010 CFU/day), consisting of Lactobacillus acidophilus DDS-1, Bifidobacterium animalis subsp. lactis UABla-12, Bifidobacterium longum UABl-14 and Bifidobacterium bifidum UABb-10 over 4 weeks. Outcomes included the patient assessment of constipation-symptom (PAC-SYM) questionnaire, stool frequency and consistency, and microbial profile.
Results: There were no significant between-group differences in the PAC-SYM score, despite significant within-group differences (P < 0.001) over the study period. The probiotic group showed a faster normalization of stool frequency and consistency, with most participants achieving a normalized profile after 1 week. Fecal samples of the probiotic group exhibited higher relative abundance of Ruminococcaceae (P = 0.0047), including the Ruminococcus genus, and lower relative abundance of Erysipelotrichaceae (P = 0.0172) at end-point compared with baseline. Placebo group samples showed similar abundance profiles over the study, with the exception of Clostridiaceae, which was lower at the study end-point (P = 0.0033). Among treated participants, all four probiotic strains were significantly more abundant after the intervention.
Conclusions: No significant differences were observed in symptomology, with both groups showing a more than 20% improvement. However, the probiotic helped modulate bowel function earlier than the placebo, with a corresponding shift to a more fibrolytic microbiota.
Keywords: bowel habit; functional constipation; microbiome; probiotic; randomized controlled trial.
© 2019 The Authors. Journal of Digestive Diseases published by Chinese Medical Association Shanghai Branch, Chinese Society of Gastroenterology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.