A candidate probiotic with unfavourable effects in subjects with irritable bowel syndrome: a randomised controlled trial

Solveig C Ligaarden,Lars Axelsson,Per G Farup,Stian Lydersen,Kristine Naterstad

doi:10.1186/1471-230x-10-16

Abstract

BackgroundSome probiotics have shown efficacy for patients with irritable bowel syndrome (IBS). Lactobacillus (L.) plantarum MF1298 was found to have the best in vitro probiotic properties of 22 strains of lactobacilli. The aim of this study was to investigate the symptomatic effect of L. plantarum MF1298 in subjects with IBS. Primary outcome was treatment preference and secondary outcomes were number of weeks with satisfactory relief of symptoms and IBS sum score.MethodsThe design was a randomised double blind placebo-controlled crossover trial. 16 subjects with IBS underwent two three-week periods of daily intake of one capsule of 1010 CFU L. plantarum MF 1298 or placebo separated by a four-week washout period.ResultsThirteen participants (81%; 95% CI 57% to 93%; P = 0.012) preferred placebo to L. plantarum MF1298 treatment. The mean (SD) number of weeks with satisfactory relief of symptoms in the periods with L. plantarum MF1298 and placebo were 0.50 (0.89) and 1.44 (1.26), respectively (P = 0.006). IBS sum score was 6.44 (1.81) in the period with L. plantarum MF1298 treatment compared with 5.35 (1.77) in the period with placebo (P = 0.010). With a clinically significant difference in the IBS sum score of 2 in disfavour of active treatment, the number needed to harm was 3.7, 95% CI 2.3 to 10.9.ConclusionsThis trial shows for the first time an unfavourable effect on symptoms in subjects with IBS after intake of a potential probiotic.The trial registration numberClinical trials NCT00355810.

Highlights

Some probiotics have shown efficacy for patients with irritable bowel syndrome (IBS)
Thirteen participants (81%; confidence interval (CI) 57% to 93%; P = 0.012) preferred placebo to L. plantarum MF1298 treatment
The number of weeks with satisfactory relief of symptoms was statistically significantly higher in the placebo period compared with the L. plantarum MF1298 period (Table 1 and 2) and the IBS sum score and the score for diarrhoea were significantly higher in the period of L. plantarum MF1298 treatment than with placebo (Table1)

Summary

Introduction

Some probiotics have shown efficacy for patients with irritable bowel syndrome (IBS). Lactobacillus (L.) plantarum MF1298 was found to have the best in vitro probiotic properties of 22 strains of lactobacilli. Primary outcome was treatment preference and secondary outcomes were number of weeks with satisfactory relief of symptoms and IBS sum score. Irritable bowel syndrome (IBS) is the most frequent functional gastrointestinal disorder, with a prevalence of 5-11% in most countries [1]. The human gut contains over 1000 different bacterial species and an indeterminate number of strains of which a minority of the strains is cultivable [4] Probiotics are defined as “live microorganisms which when administered in adequate amounts confer a health benefit on the host” [5].

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