Effectiveness and Safety of Probiotics for Patients with Constipation-Predominant Irritable Bowel Syndrome: A Systematic Review and Meta-Analysis of 10 Randomized Controlled Trials

Abstract

To perform a systematic review and meta-analysis to evaluate the effectiveness and safety of probiotics in the treatment of constipation-predominant irritable bowel syndrome (IBS-C), we searched for randomized controlled trials (RCTs) comparing probiotic care versus placebos for patients with IBS-C in five comprehensive databases (March 2022). The risk of bias was assessed using the Cochrane Collaboration Risk of Bias Tool. RevMan 5.3 was used to perform a meta-analysis on stool consistency, abdominal pain, bloating, quality of life (QoL), fecal Bifidobacterium and Lactobacillus counts, and adverse events. The GRADE approach was used to evaluate the certainty of the evidence. Ten RCTs involving 757 patients were included. Only three studies were rated as having a low risk of bias. The meta-analysis results show that, compared to the placebo, probiotics significantly improved stool consistency (MD = 0.72, 95% CI (0.18, 1.26), p < 0.05, low quality) and increased the number of fecal Bifidobacteria (MD = 1.75, 95% CI (1.51, 2.00), p < 0.05, low quality) and Lactobacillus (MD = 1.69, 95% CI (1.48, 1.89), p < 0.05, low quality), while no significant differences were found in abdominal pain scores, bloating scores, QoL scores, or the incidence of adverse events (p > 0.05). The low-to-very low certainty evidence suggests that probiotics might improve the stool consistency of patients with IBS-C and increase the number of Bifidobacteria and Lactobacilli in feces with good safety. However, more high-quality studies with large samples are needed to verify the findings.

Non-prescription Therapeutics

“…The included studies were notable for significant heterogeneity and confounding. A meta-analysis limited to constipation-predominant IBS found that probiotics improved stool consistency, but there were no significant differences in abdominal pain, bloating, or quality of life (52).…”

Depression and lifestyle: Focusing on nutrition, exercise, and their possible relevance to molecular mechanisms

“…131 In addition, many patients with depression have IBS, which presents with chronic abdominal pain, diarrhea, and constipation of unknown cause (approximately 30% in the authors' cases above [Aizawa et al 132 ]). Since the efficacy of probiotics on IBS has been demonstrated by multiple meta-analytic studies, 135,136 for these cases, in particular, probiotics and fermented food containing beneficial microbes should be utilized and recommended.…”

Probiotics in irritable bowel syndrome and inflammatory bowel disease: review of mechanisms and effectiveness

“…Details of many older trials that are not the focus of the current review can be found in that report. At least six systematic reviews have since been published on probiotics in IBS, examining the effects of probiotics at different levels of specificity [23 ▪ –28 ▪ ]; the considerable variation in reported effectiveness between different genera, species and strains is summarized in Table 1.…”

“…However, aggregating the effects of different probiotics into a meta-analysis should be undertaken with caution as different probiotics have different characteristics that will inevitably impact on their efficacy. Indeed, network meta-analyses at genus and species levels showed differential effects across specific probiotics in IBS-C and IBS-D [24 ▪ ,27 ▪ ]. At a strain level, the effects were even more specific, with only four of six probiotics meta-analysed shown to be effective for improving global symptoms ( Bacillus coagulans MTCC5260, Bifidobacterium infantis 35624, two multistrain mixtures), and only four of 12 probiotics effective for reducing abdominal pain ( B. coagulans MTCC5260, Lactobacillus rhamnosus GG, two multistrain mixtures) [23 ▪ ].…”