Systematic review with meta-analysis: review of donor features, procedures and outcomes in 168 clinical studies of faecal microbiota transplantation

Background Faecal microbiota transplantation (FMT) is effective for Clostridium difficile infections (CDI) refractory to standard treatment and is being studied in other diseases. Aim To evaluate donor characteristics, procedures and clinical outcomes of FMT. Methods We systematically reviewed FMT studies published up to 29 August 2018 using MEDLINE (R) and EMBASE and identified clinical studies with FMT donor information. We reported data on donor characteristics, screening criteria, administration, clinical outcomes and adverse events. Results Among 5267 reports, 239 full-text articles were screened and 168 articles were included. FMT was performed commonly for CDI (n = 108) and inflammatory bowel disease (IBD) (n = 31). We reported characteristics of 1513 donors [58% male; mean age, 34.3 years; mean body mass index, 21.6]. Donors in Asia were younger than the West (mean age 30.7 vs 32.9, P = 0.00075). Less than 50% of studies screened donors for transmittable pathogens. Final cure rate for CDI was 95.6% (95% confidence interval [CI], 93.9%-97.1%) and final remission rates for ulcerative colitis (UC) and Crohn's disease (CD) were 39.6% (95% CI, 25.4%-54.6%) and 47.5% (95% CI, 29.4%-65.8%), respectively. Cure rates in CDI and final remission rates for CD and UC were comparable across all routes of FMT administration. Overall adverse event incidence was <1%, mostly GI-related. Adverse event rates did not differ significantly between routes of FMT administration or indication. Conclusions In a systematic review assessing donor characteristics and FMT efficacy, we observed heterogeneity in donor selection, application and outcomes of FMT. These data can facilitate standardisation of FMT protocols for various diseases.