Any Future for Fecal Microbiota Transplantation as Treatment Strategy for Inflammatory Bowel Diseases?

Fecal microbiota transplantation (FMT) is a novel therapeutic procedure aiming at restoring a normal intestinal microbiota by application of fecal microorganisms from a healthy subject into the gastrointestinal tract of a patient. FMT is the most effective treatment for recurrent Clostridium difficile infections (CDI). These infections also occur in patients with inflammatory bowel diseases (IBDs), where case series demonstrated a successful treatment of CDI by FMT in 83-92% of patients. The effect of FMT on the activity of IBD has mainly been investigated in ulcerative colitis (UC) patients, including 3 randomized controlled trials. So far, 2 randomized controlled trials showed a superiority of FMT compared to placebo in inducing remission in UC, while 1 study found no significant difference to placebo. The variation in response to FMT between these studies as well as in the uncontrolled trials might be explained by many differences in the way of FMT application, patient pretreatment and patient and donor selection. The data for the use of FMT in Crohn's disease and pouchitis are sparse; currently, no conclusion can be drawn regarding the effectiveness of FMT in these indications. It needs to be noted that cases of IBD activation after FMT have been reported. So far, FMT can only be recommended to be used for the treatment of concomitant CDI in IBD in clinical practice. For treating IBD irrespective of CDI, FMT should be only used in clinical trials. Current forms of FMT, especially protocols using repeated application, are very time and personnel consuming. Future trends are the use of defined stable microbiota preparations, in particular oral preparations, which will enable better and larger controlled trails for investigating FMT in IBD.