The Role of Fecal Microbiota Transplantation in the Induction of Remission in Ulcerative Colitis

Background: Considerable research supports an important role for the microbiome and/or microbiome-host immune system interactions in the pathogenesis of inflammatory bowel disease (IBD). Consequently, microbiota-modulating interventions, such as fecal microbiota transplantation (FMT), have attracted interest in the management of IBD, including ulcerative colitis (UC). Summary: While the clinical response to FMT in UC has varied between different studies, results to date may offer guidance toward optimal use of FMT. Thus, increased microbiome biodiversity, the presence of short-chain fatty acid-producing bacteria, Clostridium clusters IV and XIVa, Odoribacter splanchnicus, and reduced levels of Caudovirales bacteriophages have been identified as characteristics of the donor microbiome that predict a positive response. However, inconsistency in FMT protocol between studies confounds their interpretation, so it is currently difficult to predict response and premature to recommend FMT, in general, as a treatment for UC. Additional randomized controlled trials designed based on previous findings and employing a standardized protocol are needed to define the role of FMT in the management of UC. Key Messages: There is a well-developed rationale for the use of microbiome-modulating interventions in UC. Despite variations in study protocol and limitations in study design that confound their interpretation, FMT seems to benefit patients with UC, overall. Available data identify factors predicting FMT response and should lead to the development of optimal FMT study protocols.