Only two RCTs and some lower level data were available in this review in the Annals of Internal Medicine. From the review:
Study Selection: Any study of FMT to treat adult patients with CDI; case reports were only used to report harms.
Data Extraction: Data were extracted by 1 author and verified by another; 2 authors independently assessed risk of bias and strength of evidence.
Data Synthesis: Two randomized, controlled trials (RCTs); 28 case-series studies; and 5 case reports were included. Two RCTs and 21 case-series studies (516 patients receiving FMT) reported using FMT for patients with recurrent CDI. A high proportion of treated patients had symptom resolution; however, the role of previous antimicrobials is unclear. One RCT comparing FMT with 2 control groups (n = 43) reported resolution of symptoms in 81%, 31%, and 23% of the FMT, vancomycin, or vancomycin-plus-bowel lavage groups, respectively (P less than 0.001 for both control groups vs. FMT). An RCT comparing FMT route (n = 20) reported no difference between groups (60% in the nasogastric tube group and 80% in the colonoscopy group; P = 0.63). Across all studies for recurrent CDI, symptom resolution was seen in 85% of cases. In 7 case-series studies of patients with refractory CDI, symptom resolution ranged from 0% to 100%. Among 7 patients treated with FMT for initial CDI, results were mixed.
Limitation: Most studies were uncontrolled case-series studies; only 2 RCTs were available for analysis.
Conclusion: Fecal microbiota transplantation may have a substantial effect with few short-term adverse events for recurrent CDI. Evidence is insufficient on FMT for refractory or initial CDI treatment and on whether effects vary by donor, preparation, or delivery method.