Background: Given the importance of the enteric microbiota in the pathogenesis of the inflammatory bowel diseases, faecal microbiota transplantation (FMT) has been advocated as a potential therapeutic strategy, and has been the recent subject of increasing research. We thus performed a systematic review and meta-analysis to assess the effectiveness and safety of FMT in the treatment of inflammatory bowel diseases.
Methods: A systematic review of the literature was conducted up until the end of March 2016 in accordance with PRISMA and Cochrane recommendations. Electronic databases were searched, along with hand searching of major conference proceedings. Studies were excluded if patients had co-infection or if data was pooled across disease subtypes (ulcerative colitis (UC), Crohn's disease (CD), pouchitis) and could not be individually extracted. Clinical remission was established as the primary outcome; clinical response, endoscopic remission and safety were secondary outcomes. Pooled effect sizes and 95% confidence intervals were obtained using the random effects model. Heterogeneity, sensitivity and subgroup analyses were also performed.
Results: 5940 records were identified of which 82 articles were reviewed. Thirty eight studies were included (29 in UC [including 3 randomised controlled trials], 11 in CD, 3 in pouchitis) reporting on 371 UC, 73 CD and 22 pouchitis patients. Overall, 37.5% (139/371) of UC patients, 49.5% (36/73) of CD patients and 18% (4/22) of pouchitis patients achieved clinical remission during follow-up. Among the cohort studies, the pooled proportion of patients that achieved clinical remission was 33% (95% CI 24%– 44%) for UC with a moderate risk of heterogeneity (Cochran's Q, p=0.121; I2 =31%) and 53% (95% CI 30%– 75%) for CD with a moderate risk of heterogeneity (Cochran's Q, p=0.081; I2 =49%). For the 3 RCTs of FMT in UC, there was borderline benefit in clinical remission (P-OR =2.37, 95% CI =0.91–6.19, p=0.078) with moderate heterogeneity (Cochran's Q, p=0.168; I2 =44%). The controlled trial and cohort data suggest remission in UC is improved with increased number of FMT infusions and administration via the lower gastrointestinal tract. Most adverse events were transient minor gastrointestinal complaints. Microbiota analysis was performed in 16 studies, with many identifying a shift in recipient microbiota profile towards that of the donor post FMT.
Conclusions: There is a need for additional well designed controlled studies of FMT in IBD, especially in CD and pouchitis. FMT appears to be effective in the induction treatment of UC, particularly with increasing number of infusions. Long term durability and safety remain unclear.