Eleven studies (273 patients) were included in the review. There were no randomised controlled trials; data were derived largely from non-controlled observational studies. None of the studies met all of the CRD criteria. None of the studies scored eight using NICE criteria (seven studies scored 4 or more, and four studies scored less than 4). Follow-up ranged from three weeks to eight years.
Faecal microbiota transplantation achieved clinical resolution in 245 out of 273 patients. The weighted pooled resolution rate was 89.1% (95% CI 84.0% to 93.3%; 11 studies; Ι²=33.7%). Success rates were similar when data were re-examined using the review authors interpretation of clinical resolution.
In subgroup analyses, lower gastrointestinal delivery (using colonoscopy/enema) of faecal microbiota transplantation was favoured compared with upper gastrointestinal delivery (un-weighted rate proportion difference 9.1%, 95% CI -0.1% to 22.1%; weighted rate proportion difference was not statistically significant). Higher quality studies showed significantly improved clinical resolution compared with lower quality studies (un-weighted rate proportion difference 11.7%, 95% CI 3.7% to 21.5%; weighted rate proportion difference 12.3%, 95% CI 3.5% to 21.1%). There were no statistically significant differences in clinical resolution rate between patient-selected versus anonymous healthy donors.
There were no adverse events related to faecal microbiota transplantation, but this was not a primary outcome in any of the studies.