Fecal Microbiota Transplantation and Health Outcomes: An Umbrella Review of Meta-Analyses of Randomized Controlled Trials.
Level 1 - systematic review of randomized trials
Umbrella review synthesizing meta-analyses of randomized controlled trials
PubMed 35832379 · doi:10.3389/fcimb.2022.899845
What was done
Authors searched PubMed, Embase, and Cochrane Library through August 6, 2021, for meta-analyses of randomized controlled trials (RCTs) evaluating fecal microbiota transplantation (FMT) across various health outcomes. Pooled effect estimates were recalculated using random-effects models. Methodological quality was evaluated using AMSTAR 2, and the certainty of evidence for each unique outcome association was graded using GRADE.
What was found
The umbrella review included 7 meta-analyses comprising 26 RCTs (median [IQR] primary studies: 6 [2-7]; median [IQR] sample size: 267 [147-431] participants) reporting on 45 unique associations. There were 22 statistically significant associations (49%) showing beneficial outcomes for FMT in Clostridioides difficile infection, inflammatory bowel disease, functional constipation, and antibiotic resistance burden. FMT showed no positive associations for irritable bowel syndrome or metabolic syndrome. Among the 22 significant associations, 8 (36%) were supported by moderate-quality evidence, 9 (41%) by low-quality evidence, and the remaining 5 (23%) by very low-quality evidence; zero associations achieved high-quality evidence. Specific pooled numerical effect sizes were not provided in the abstract.
Why it matters
This review clarifies the landscape of FMT efficacy across clinical indications, confirming benefit for specific conditions like recurrent C. difficile and IBD while demonstrating that much of the broader evidence base remains constrained by moderate to very low certainty.
Limits
The abstract reports a limited number of primary RCTs per condition with small median sample sizes. Overall methodological quality of included meta-analyses and evidence certainty were generally low, specific numerical effect sizes and confidence intervals were omitted from the abstract, and long-term safety data were not evaluated.
Cited by
- supports Clinical trials of fecal microbiota transplantation for irritable bowel syndrome have generally failed to show strong positive patient outcomes.