Efficacy in bowel movement and change of gut microbiota on adult functional constipation patients treated with probiotics-containing products: a systematic review and meta-analysis.

2024-01
BMJ open 14(1)

PubMed: 38238054
DOI: 10.1136/bmjopen-2023-074557

Study Design

Type: Meta-Analysis
Sample size: n = 1,256
Population: adult functional constipated patients
Methods: Systematic review and meta-analysis of randomised controlled trials up to November 2022; intervention was probiotics-containing product, either probiotics or synbiotics, while the control was placebo

Objectives

This study aimed to pool the efficacy in bowel movement and explore the change of gut microbiota on adult functional constipated patients after probiotics-containing products treatment.

Design

Systematic review and meta-analysis.

Data sources

PubMed, Cochrane Library for published studies and ClinicalTrials.gov for 'grey' researches were independently investigated for randomised controlled trials up to November 2022.

Eligibility criteria, data extraction and synthesis

The intervention was probiotics-containing product, either probiotics or synbiotics, while the control was placebo. The risk of bias was conducted. The efficacy in bowel movement was indicated by stool frequency, stool consistency and Patient Assessment of Constipation Symptom (PAC-SYM), while the change of gut microbiota was reviewed through α diversity, β diversity, change/difference in relative abundance and so on. The subgroup analysis, sensitivity analysis and random-effect meta-regression were conducted to explore the heterogeneity. The Grading of Recommendations Assessment Development and Evaluation was conducted to grade the quality of evidence.

Results

17 studies, comprising 1256 participants, were included with perfect agreements between two researchers (kappa statistic=0.797). Compared with placebo, probiotics-containing products significantly increased the stool frequency (weighted mean difference, WMD 0.93, 95% CI 0.47 to 1.40, p=0.000, I^²=84.5%, 'low'), improved the stool consistency (WMD 0.38, 95% CI 0.05 to 0.70, p=0.023, I²=81.6%, 'very low') and reduced the PAC-SYM (WMD -0.28, 95% CI: -0.45 to -0.11, p=0.001, I²=55.7%, 'very low'). In subgroup analysis, synbiotics was superior to probiotics to increase stool frequency. Probiotics-containing products might not affect α or β diversity, but would increase the relative abundance of specific strain.

Conclusions

Probiotics-containing products, significantly increased stool frequency, improved stool consistency, and alleviated functional constipation symptoms. They increased the relative abundance of specific strain. More high-quality head-to-head randomised controlled trials are needed.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Bifidobacterium bifidum UABb-10	—	Improved Bowel Movement Frequency	Beneficial	Moderate	View source Compared with placebo, probiotics-containing products significantly increased the stool frequency (weighted mean difference, WMD 0.93, 95% CI 0.47 to 1.40, p=0.000, I²=84.5%, 'low')
Bifidobacterium bifidum UABb-10	—	Improved Constipation Symptoms	Beneficial	Small	View source and reduced the PAC-SYM (WMD -0.28, 95% CI: -0.45 to -0.11, p=0.001, I²=55.7%, 'very low')
Bifidobacterium bifidum UABb-10	—	Improved Stool Consistency	Beneficial	Small	View source improved the stool consistency (WMD 0.38, 95% CI 0.05 to 0.70, p=0.023, I²=81.6%, 'very low')
Bifidobacterium longum UABl-14	—	Improved Bowel Movement Frequency	Beneficial	Moderate	View source Compared with placebo, probiotics-containing products significantly increased the stool frequency (weighted mean difference, WMD 0.93, 95% CI 0.47 to 1.40, p=0.000, I²=84.5%, 'low')
Bifidobacterium longum UABl-14	—	Improved Constipation Symptoms	Beneficial	Small	View source and reduced the PAC-SYM (WMD -0.28, 95% CI: -0.45 to -0.11, p=0.001, I²=55.7%, 'very low')
Bifidobacterium longum UABl-14	—	Improved Stool Consistency	Beneficial	Small	View source improved the stool consistency (WMD 0.38, 95% CI 0.05 to 0.70, p=0.023, I²=81.6%, 'very low')