Strain-specific and outcome-specific efficacy of probiotics for the treatment of irritable bowel syndrome: A systematic review and meta-analysis

Abstract

Background: Consistent guidance for choosing an appropriate probiotic for the treatment of irritable bowel syndrome is lacking. Methods: Literature databases searched included: PubMed, Google Scholar and NIH registry of clinical trials from inception to June 2021. Inclusion criteria: randomized controlled trials (RCTs) enrolling adult or pediatric IBS patients comparing probiotics against controls and 2 RCTs with common IBS outcome measures within each type of probiotic. Five common measures of IBS symptoms (changes in global Irritable Bowel Syndrome Severity Scoring System or IBS-SSS scores, frequency of global responders, changes in bloating or abdominal pain scores and frequency of abdominal pain relief) were used. This study was registered at Prospero (#CRD42018109169). Findings: We screened 521 studies and included 42 randomized controlled trials (45 treatment arms, N = 3856). Four probiotics demonstrated significant reduction in abdominal pain relief: B. coagulans MTCC5260 (RR= 4 . 9, 95% C.I. 3 . 3, 7 . 3), L. plantarum 299v (RR= 4 . 6, 95% CI 1 . 9, 11 . 0), S. boulardii CNCM I-745 (RR= 1 . 5, 95% C.I. 1 . 1, 2 . 1) and S. cerevisiae CNCM I-3856 (RR= 1 . 3, 95% C.I. 1 . 04, 1 . 6). Mild-moderate adverse events were reported in 51% of the trials, none were more associated with the probiotic compared to controls. Interpretation: Although the analysis of probiotic efficacy was limited by the diversity of IBS outcomes used in trials and lack of confirmatory trials for some strains, six single-strain probiotics and three different types of probiotic mixtures showed significant efficacy for at least one IBS outcome measure. These results might be relevant to clinical practice and policy.

Probiotics in the Management of Mental and Gastrointestinal Post-COVID Symptomes

“…Marlicz et al further analysis of the effectiveness of individual strains of lactobacilli in IBS showed the greatest effectiveness of L. plantarum 299v, the strain for which the largest number of RCTs were conducted [ 146 ]. These observations were also confirmed by McFarland et al in the latest meta-analysis on the effectiveness of individual probiotic strains in patients with IBS [ 147 ]. The effectiveness of L. plantarum 299v was also confirmed in a large study, carried out in 25 medical centers in Germany, for a period of 12 weeks, comprising 221 patients with IBS.…”

Administration of probiotics to healthy volunteers: effects on reactivity of intestinal mucosa and systemic leukocytes

“…It is important to study the effect of probiotic strains separately since the health effect can differ between strains. For example, recent meta-analyses have shown that there is strain-specific efficacy of probiotics in preventing gastrointestinal tract infections among infants and children attending childcare centres and in the treatment of irritable bowel syndrome [ 25 , 26 ]. The scientific and clinically interesting question is if you can induce a strengthening of the mucosa before a potential insult, therefore we think that the relevant comparison is to compare before and after administration of the same probiotic bacterium.…”

Modulating the gut microenvironment as a treatment strategy for irritable bowel syndrome: a narrative review

“…Here we focus on placebo-controlled studies that have investigated the effect of probiotics on gut microenvironment and their interaction with IBS symptoms. To date, studies assessing the effects of probiotics on IBS symptoms as well as published meta-analyses provide mixed results regarding the clinical efficacy of probiotic products in IBS (Ford et al, 2018; McFarland et al, 2021).…”