Efficacy and dose response of Lactiplantibacillus plantarum in diarrhea-predominant irritable bowel syndrome

BACKGROUND Probiotics have shown promise in alleviating symptoms of diarrhea-predominant irritable bowel syndrome (IBS-D); however, the certainty of evidence is low. Wellpowered randomized controlled dose-ranging trials are warranted on promising single-strain candidates. AIM To investigate the clinical efficacy of Lactiplantibacillus plantarum (L. plantarum) Lpla33 (DSM34428) in adults with IBS-D. METHODS This is a randomized, double- blind, placebo-controlled, multi- center, and doseranging study. Three hundred and seven adults, 18-70 years of age, with IBS-D, according to Rome IV criteria, were allocated (1:1:1) to receive placebo or L. plantarum Lpla33 at 1 x 10(9) (1B) or 1 x 10(10) (10B) colony-forming units/d over an 8wk intervention period. The primary outcome was the change in IBS severity scoring system (IBS-SSS) total score after 8 wk, while secondary and exploratory outcomes included abdominal pain severity, IBS related quality of life, stool and microbial profile, and perceived stress. RESULTS IBS- SSS was significantly reduced, after 8 wk, in participants receiving L. plantarum 1B (-128.45 +/- 83.30; P < 0.001) and L. plantarum 10B (-156.77 +/- 99.06; P < 0.001), compared to placebo (-58.82 +/- 74.75). Further, a dose- ranging effect was observed, with a greater absolute reduction in the L. plantarum 10B group (P < 0.05). A reduction in sub-scores related to abdominal pain, abdominal distension, bowel habits, and quality of life was observed in both L. plantarum groups compared to placebo (P < 0.001). Further, 62.5% and 88.4% of participants administered L. plantarum 1B and 10B, respectively, were classified as stool consistency responders based on a reduction in diarrheal stool form, as compared to 26.3% in the placebo group (P < 0.001). In contrast, no significant shifts were observed in microbial diversity. CONCLUSION L. plantarum Lpla33 (DSM34428) is well tolerated and improves IBS symptom severity with a dose- ranging effect and a corresponding normalization of bowel habits in adults with IBS-D.

Automated summary

This study found that Lactiplantibacillus plantarum (L. plantarum) Lpla33 (DSM34428) significantly improved symptoms in patients with IBS-D, reducing abdominal pain and bloating, and restoring normal bowel habits.