Fecal microbiota transplantation: current status and future directions.

The etiology of ulcerative colitis (UC) is unknown. However, evidence suggests that host–microbial interactions play an important role in the pathogenesis of colitis, contributing to longstanding inflammation. The gastrointestinal bacterial flora may also be an important factor in the maintenance of inflammatory bowel disease (IBD), but the exact mechanisms remain elusive. Fecal bacteriotherapy, now termed fecal microbiota transplantation (FMT), has gained prominence in light of the recent epidemic of Clostridium difficile infection (CDI) in North America and Europe. Coupled with the emergence of a hypervirulent strain of C. difficile, FMT is likely to feature prominently in the treatment of both relapsing and severe C. difficile colitis. Given that FMT is capable of successfully reversing CDI-associated colitis and is arguably the most complete and ideal probiotic, one can see the potential value of FMT in other bacteria-mediated diseases such as idiopathic UC. Kahn and colleagues from the University of Chicago Inflammatory Bowel Disease Center (IL, USA) reported their results from a recent qualitative study assessing patients’ readiness for FMT in UC [1]. The premise of the study was to assess patients’ attitudes and concerns towards FMT therapy as a potential treatment option for the UC community. Their questioning encompassed five broad areas in relation to FMT, including: patients’ impressions of FMT, benefits, risks, potential mechanisms and social concerns. The overwhelming majority of patients not only expressed their interest in FMT as a treatment option, but also expressed their desire for FMT to be readily available. Interestingly, parents of children with UC expressed fewer reservations about FMT than adult subjects, with FMT described as ‘more natural’ and therefore perceived as ‘easier and safer’ than current therapies, specifically steroids and biologics. There is no doubt that IBD poses considerable treatment challenges for physicians and patients alike, with a dearth of more specific therapeutic options currently available. Our current repertoire of various immunomodulators and antibiotics relied upon to induce and maintain remission remains imperfect in both efficacy and the level of adverse effects experienced. A variety of probiotic agents have been used in the treatment of UC with some definite, albeit minor, success [2]. However, the marked heterogeneity among various trials has provided one obstacle to advocating their use in UC. In addition, current oral probiotic doses are typically three to four orders of magnitude lower than the 100 trillion native microorganisms contained within the colon, a number likely to be even further reduced following passage through the harsh environments of the stomach and small bowel. Considerable research has been directed towards elucidating probiotics’ exact mechanisms of action, and it is Expert Rev. Gastroenterol. Hepatol. 5(6), 653–655 (2011)