The following is a summary of “Efficacy of Probiotics in Irritable Bowel Syndrome: Systematic Review and Meta-analysis,” published in the NOVEMBER 2023 issue of Gastroenterology by Goodoory, et al.

Irritable bowel syndrome (IBS) is a prevalent condition that exhibits potential improvement through the use of specific probiotics. However, identifying the most effective species and strains of probiotics for IBS management remained challenging due to variations in reported data and endpoints across studies. For a study, researchers sought to present an updated meta-analysis aiming to shed light on the matter.

They conducted a comprehensive search of MEDLINE, EMBASE, and the Cochrane Controlled Trials Register, spanning studies up to March 2023. Their inclusion criteria encompassed randomized controlled trials (RCTs) involving adult IBS patients administered probiotics compared to a placebo. They analyzed dichotomous symptom data to calculate the relative risk of continued IBS symptoms, specifically global symptoms, abdominal pain, and abdominal bloating or distension post-treatment, with a 95% CI. They also employed standardized mean differences with a 95% CI to assess continuous data and compiled data related to adverse events.

In the analysis, they identified 82 trials involving 10,332 patients. Still, it’s important to note that only 24 of these randomized controlled trials (RCTs) were considered to have a low risk of bias across all key domains. We evaluated the impact of probiotics on various aspects of irritable bowel syndrome (IBS) and found varying levels of certainty in the evidence. Regarding global IBS symptoms, we found moderate certainty in the evidence supporting the effectiveness of Escherichia strains. However, the certainty decreased to low when considering Lactobacillus strains and Lactobacillus plantarum 299V. For combination probiotics, LacClean Gold S, Duolac 7s, and Bacillus strains, the evidence was associated with very low certainty. In alleviating abdominal pain, there was low certainty in the evidence for the effectiveness of Saccharomyces cerevisae I-3856 and Bifidobacterium strains.

Nevertheless, when assessing a combination of probiotics and specific strains such as Lactobacillus, Saccharomyces, and Bacillus, the certainty dropped to a very low level. For addressing abdominal bloating or distension, the certainty in the evidence remained very low, regardless of the specific probiotics used, including combination probiotics and Bacillus strains. Importantly, when evaluating the safety of probiotics, we found that the relative risk of experiencing any adverse event was not significantly higher among patients who received probiotics. This suggests that probiotics are generally well-tolerated, as indicated by our analysis of 55 trials involving over 7,000 patients. 

The findings indicated that while certain combinations of probiotics or specific strains may offer benefits in managing IBS, the level of certainty in the evidence, as per GRADE criteria, was generally low to very low for most of their analyses. It suggested further research to establish definitive recommendations regarding probiotic use in IBS management.

Source: gastrojournal.org/article/S0016-5085(23)04838-2/fulltext