Meta-analysis of randomized controlled trials of the effects of probiotics on functional constipation in adults
Zhang C
Published in Clinical Nutrition
Methodology
Systematic review and meta-analysis of randomised controlled trials from Medline, the Cochrane Library, Web of Science and Google Scholar to April 2019; two authors independently handled selection, risk-of-bias assessment and extraction; outcomes of stool frequency, gut transit time, stool consistency and bloating pooled as weighted or standardised mean differences using a random-effects model.
Key Findings
This meta-analysis of 15 randomised controlled trials in adults with functional constipation found that probiotics reduced whole gut transit time by 13.75 hours (95% CI -21.93 to -5.56) and increased stool frequency by 0.98 bowel movements per week (95% CI 0.36 to 1.60). The benefit came from multispecies products (at least two bacteria; 1.22 extra bowel movements per week, 95% CI 0.50 to 1.94), while Bifidobacterium lactis alone (95% CI -0.27 to 2.94) and B. longum alone (95% CI -0.56 to 0.53) showed no significant effect. Multispecies probiotics also improved stool consistency and reduced bloating (-0.49, 95% CI -0.85 to -0.13), whereas single-species products did not.
Conclusions
Consumption of probiotics, in particular, multispecies probiotics, may substantially reduce the GTT, increase the stool frequency, and improve the stool consistency.
Limitations
Performance bias was high across the included trials and detection bias unclear due to inadequate reporting; products, strains, doses and durations varied widely, so results cannot be transferred to any specific commercial product.
Supplements Studied
Consumption of probiotics, in particular, multispecies probiotics, may substantially reduce the GTT, increase the stool frequency, and improve the stool consistency.
Related Health Concerns
Study Details
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This information is for educational purposes only. Always consult a healthcare professional before starting any supplement regimen.