Probiotics therapy for adults with diarrhea-predominant irritable bowel syndrome: a systematic review and meta-analysis of 10 RCTs

Int J Colorectal Dis. 2022 Nov;37(11):2263-2276. doi: 10.1007/s00384-022-04261-0. Epub 2022 Oct 17.


Purpose: Accumulating evidence showed that probiotics therapy might be effective in treating diarrhea-predominant irritable bowel syndrome (IBS-D). This study aimed to evaluate the effectiveness and safety of probiotics therapy for the treatment of IBS-D.

Methods: We performed a comprehensive literature search in eight electronic databases, and gray literature from inception to August 4, 2021. Randomized controlled trials (RCTs) of probiotics therapy for the treatment of IBS-D were included and the quality was assessed using the risk of bias tool recommended by the Cochrane Handbook version 5.1.0. RevMan 5.4 software was used to perform the meta-analysis on the outcomes of IBS-D symptoms, abdominal pain, quality of life, and abdominal distension. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of evidence.

Results: Ten RCTs evaluating 943 patients were identified. Only one study had unclear risk of bias, while nine studies had a high risk of bias. The meta-analysis results showed that, compared to the placebo, probiotics therapy significantly decreased the score of IBS-D symptoms (SMD = - 0.55, 95% CI: [- 0.83, - 0.27], P < 0.05), abdominal pain (SMD = - 0.43, 95% CI: [- 0.57, - 0.29], P < 0.05), and abdominal distension (SMD = - 0.45, 95%CI: [- 0.81, - 0.09], P < 0.05). There was no statistical difference in the quality of life. However, all the certainty of evidence was very low.

Conclusion: Very low certainty evidence showed that probiotics might be an effective treatment for improving the IBS-D symptoms, abdominal pain, and abdominal distension, in adult IBS-D patients. However, these conclusions should be supported by high-quality evidence.

Keywords: Diarrhea‐predominant irritable bowel syndrome; Probiotics; Randomized controlled trials; Systematic review.

Publication types

  • Meta-Analysis
  • Systematic Review
  • Review

MeSH terms

  • Abdominal Pain / etiology
  • Abdominal Pain / therapy
  • Adult
  • Diarrhea / etiology
  • Diarrhea / therapy
  • Humans
  • Irritable Bowel Syndrome* / complications
  • Irritable Bowel Syndrome* / diagnosis
  • Irritable Bowel Syndrome* / therapy
  • Probiotics* / therapeutic use
  • Treatment Outcome