Systematic Review and Meta-Analysis: Plant-Based Therapy for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common disorder of brain-gut interaction that presents with abdominal pain, bloating associated with variable stool consistency. Many IBS patients prefer plant-based preparations to pharmacological therapy; however, the utility of this approach is not well established. To address this issue, a systematic review with meta-analysis to assess the efficacy and safety of plant-based therapy in IBS patients was performed. Literature search with 3 electronic databases (Medline via PubMed, Embase via Ovid, and Web of Science Core Collection) from inception to May 2024. Efficacy was assessed using dichotomous ratings of change in IBS symptoms. A random effects model with 95% confidence intervals was used. Through the screening process, 60 eligible studies were identified (6329 patients). Meta-analysis was performed for fiber (8 studies, RR = 1.22; 95% CI: 1.00-1.49), peppermint oil (7 studies, RR = 1.63; 95% CI: 1.33-2.00), Aloe vera (3 studies, RR = 1.25; 95% CI: 0.76-2.06), and Chinese herbal medicine (7 studies, RR = 1.56; 95% CI: 1.27-1.92). For other plant-based substances investigated in at least one randomized controlled trial (RCT) (e.g., St. John's wort, Anise oil), there were insufficient data for a meta-analysis. The quality of many studies was limited. The findings demonstrate that the treatment of IBS patients with peppermint oil and Chinese herbal medicine were more effective than placebo and had a good safety profile. Dietary fiber showed effects that approached significance. Further, well-powered RCTs are needed to establish the place of plant-based preparations in IBS treatment.