Published online Jul 28, 2023. doi: 10.3748/wjg.v29.i28.4451
Peer-review started: June 9, 2023
First decision: June 14, 2023
Revised: June 27, 2023
Accepted: July 11, 2023
Article in press: July 11, 2023
Published online: July 28, 2023
Processing time: 46 Days and 17.4 Hours
Irritable bowel syndrome (IBS) is a disorder of gut-brain interaction characterized by abdominal pain in association with altered bowel habits and further classified by the predominant stool pattern. Global prevalence is high, with diarrhea predominant subtype (IBS-D) considered the most common. IBS-D has a significant impact on quality of life, and clinical management remains challenging due to the variety of symptoms to address.
A recent meta-analysis showed probiotics to be safe and superior to placebo for alleviating global IBS-D symptoms. However, the certainty of evidence is low, due in part to significant heterogeneity between studies. There is therefore a need for well-powered randomized controlled trials on promising probiotic candidates for IBS-D.
To assess the efficacy of a probiotic candidate strain, Lactiplantibacillus plantarum (L. plantarum) Lpla33 (DSM34428), in adults with IBS-D. The primary outcome was the change in the IBS severity scoring system (IBS-SSS) total score after 8 wk. Additional outcomes included the change in abdominal pain severity, IBS-related quality of life, stool and microbial profile, and perceived stress.
Adults meeting Rome IV diagnostic criteria for IBS-D were recruited from 12 gastroenterology specialized centers across India. In this randomized, double-blind, placebo-controlled, multi-center, parallel-arm, and dose-ranging study, a total of 307 adults meeting the inclusion criteria were allocated (1:1:1) to receive placebo or L. plantarum Lpla33 at one of two doses [1 × 109 colony-forming units (CFU)/d (1B) or 1 × 1010 CFU/d (10B)] over 8 wk.
The primary outcome, IBS-SSS total score, was significantly reduced after 8 wk in participants receiving L. plantarum compared to placebo (P < 0.001), with a dose-ranging effect when comparing the two L. plantarum groups (P < 0.05). In total, 59.6% and 72.6% of participants in the L. plantarum 1B and L. plantarum 10B groups, respectively, were considered significant responders based on a 95-point reduction threshold, as compared to 26.3% in the placebo group (P < 0.001). Additionally, 62.5% and 88.4% of participants administered L. plantarum 1B and 10B, respectively, demonstrated a significant reduction in diarrheal stool form as compared to 26.3% in the placebo group (P < 0.001).
L. plantarum Lpla33 is well tolerated and demonstrates dose-ranging efficacy in alleviating IBS symptom severity with a corresponding normalization of bowel habits in adults with IBS-D.
Future research should incorporate multi-omics analyses and associated biomarkers to better understand the mechanisms of action involved.