Probiotics and synbiotics in chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials

Alice van der Schoot; Carina Helander; Kevin Whelan; Eirini Dimidi

doi:10.1016/j.clnu.2022.10.015

Probiotics and synbiotics in chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials

Clin Nutr. 2022 Dec;41(12):2759-2777. doi: 10.1016/j.clnu.2022.10.015. Epub 2022 Oct 27.

Authors

Alice van der Schoot¹, Carina Helander², Kevin Whelan³, Eirini Dimidi⁴

Affiliations

¹ Department of Nutritional Sciences, King's College London, 150 Stamford Street, London, SE1 9NH, United Kingdom. Electronic address: alice.van_der_schoot@kcl.ac.uk.
² Department of Nutritional Sciences, King's College London, 150 Stamford Street, London, SE1 9NH, United Kingdom. Electronic address: carina.helander@kcl.ac.uk.
³ Department of Nutritional Sciences, King's College London, 150 Stamford Street, London, SE1 9NH, United Kingdom. Electronic address: kevin.whelan@kcl.ac.uk.
⁴ Department of Nutritional Sciences, King's College London, 150 Stamford Street, London, SE1 9NH, United Kingdom. Electronic address: eirini.dimidi@kcl.ac.uk.

PMID: 36372047
DOI: 10.1016/j.clnu.2022.10.015

Abstract

Background & aims: Probiotics and synbiotics have been increasingly investigated for the management of chronic constipation. We aimed to investigate the effect of probiotics and synbiotics on stool output, gut transit time, symptoms and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).

Methods: Studies were identified using electronic databases, backward citation and hand-searching abstracts. The search date was 10 July 2022. RCTs reporting administration of probiotics or synbiotics in adults with chronic constipation were included. Risk of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Meta-analysis was conducted separately for probiotics and synbiotics. Results were synthesized using risk ratios (RRs), mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using a random-effects model.

Results: Thirty RCTs investigating probiotics and four RCTs investigating synbiotics were included. Overall, 369/647 (57%) responded to probiotic treatment and 252/567 (44%) to control (RR 1.28, 95% CI 1.07, 1.52, p = 0.007). Probiotics increased stool frequency (SMD 0.71, 95% CI 0.37, 1.04, p < 0.00001), with Bifidobacterium lactis having a significant effect, but not mixtures of probiotics, Bacillus coagulans Unique IS2 or Lactobacillus casei Shirota. Probiotics did not impact stool consistency (SMD 0.26, 95% CI -0.03, 0.54, p = 0.08). Probiotics improved integrative symptom scores compared to control (SMD -0.46, 95% CI -0.89, -0.04). Synbiotics did not impact stool output or integrative symptom scores compared to control.

Conclusions: Certain probiotics may improve response to treatment, stool frequency and integrative constipation symptoms, providing cautious optimism for their use as a dietary management option. There is currently insufficient evidence to recommend synbiotics in the management of chronic constipation. Caution is needed when interpreting these results due to high heterogeneity and risk of bias amongst the studies.

Keywords: Constipation; Meta-analysis; Probiotics; Synbiotics; Systematic review.

Publication types

Meta-Analysis
Systematic Review
Research Support, Non-U.S. Gov't

MeSH terms

Adult
Bifidobacterium animalis*
Constipation / therapy
Humans
Probiotics* / therapeutic use
Randomized Controlled Trials as Topic
Synbiotics*