The following is a summary of “A meta-analysis of randomized controlled trials evaluating the effectiveness of fecal microbiota transplantation for patients with irritable bowel syndrome,” published in the July 2024 issue of Gastroenterology by Wang et al.

Studies on fecal microbiota transplantation (FMT) to treat irritable bowel syndrome (IBS) have shown mixed results in RCTs.

Researchers conducted a retrospective study to examine the past effectiveness of FMT for IBS and explore the gut-emotion link.

They thoroughly searched PubMed, Embase, Web of Science, and the Cochrane Library using diverse strategies to identify eligible studies. Criteria for data extraction included RCTs assessing FMT efficacy vs. placebo in adult patients (≥ 18 years old) with IBS. A meta-analysis followed to evaluate the summary relative risk (RR) and corresponding 95% CIs.

The results showed 3,065 potentially relevant records and 10 RCTs involving 573 subjects. Meta-analyses revealed no significant differences in short-term (12 weeks) global improvement (RR 0.20, 95% CI -0.04 to 0.44) and long-term (52 weeks) global improvement (RR 1.38, 95% CI 0.87 to 2.21). Short-term (12 weeks) (SMD − 48.16, 95% CI -102.13 to 5.81, I² = 90%) and long-term (24 weeks) (SMD 2.16, 95% CI -60.52 to 64.83, I² = 68%) IBS-SSS showed no significant differences. Short-term improvement in IBS-QoL (SMD 10.11, 95% CI 0.71 to 19.51, I²= 82%) showed a statistically significant difference despite high bias risk. Long-term improvement (24 weeks and 54 weeks) showed no significant differences between the FMT and placebo groups (SMD 7.56, 95% CI 1.60 to 13.52, I² = 0%; SMD 6.62, 95% CI -0.85 to 14.08, I² = 0%). Sensitivity analysis revealed significant effects based on Rome IV criteria (RR 16.48, 95% CI 7.22 to 37.62) and diagnostic methods. Mixed stool FMT based on data from two RCTs showed no significant difference (RR 0.94, 95% CI 0.66 to -1.34). Remission of depression exhibited no significant difference between the FMT and placebo groups at 12 weeks (SMD − 0.26, 95% CI -3.09 to 2.58) and at 24 weeks (SMD − 2.26, 95% CI -12.96 to 8.45). Transient, self-limiting AEs were associated with FMT.

Investigators concluded that past RCTs on FMT for general IBS were inconclusive, highlighting the need for better patient selection and further research into its effectiveness.

Source: bmcgastroenterol.biomedcentral.com/articles/10.1186/s12876-024-03311-x