Published online Sep 7, 2022. doi: 10.3748/wjg.v28.i33.4762
Peer-review started: March 12, 2022
First decision: April 6, 2022
Revised: May 6, 2022
Accepted: August 16, 2022
Article in press: August 16, 2022
Published online: September 7, 2022
Fecal microbiota transplantation (FMT) is a successful method for treating recurrent Clostridioides difficile (C. difficile) infection (rCDI) with around 90% efficacy. Due to the relative simplicity of this approach, it is being widely used and currently, thousands of patients have been treated with FMT worldwide. Nonetheless, the mechanisms underlying its effects are just beginning to be understood. Data indicate that FMT effectiveness is due to a combination of microbiological direct mechanisms against C. difficile, but also through indirect mechanisms including the production of microbiota-derived metabolites as secondary bile acids and short chain fatty acids. Moreover, the modulation of the strong inflammatory response triggered by C. difficile after FMT seems to rely on a pivotal role of regulatory T cells, which would be responsible for the reduction of several cells and soluble inflammatory mediators, ensuing normalization of the intestinal mucosal immune system. In this minireview, we analyze recent advances in these immunological aspects associated with the efficacy of FMT.
Core Tip: Fecal microbiota transplantation (FMT) is an excellent treatment option of pseudomembranous colitis due to Clostridiodes difficile infection (CDI) because of its remarkable effectiveness. Moreover, FMT is a promising therapy for several other disorders in which dysbiosis is an important pathological factor. The mechanisms of FMT have begun to be dissected and include the restoration of the commensal microbial community structure and the modulation of several components of the immune system. This minireview focus on the FMT immune-related mechanisms for CDI.