Considering the Immune System during Fecal Microbiota Transplantation for Clostridioides difficile Infection

Our understanding and utilization of fecal microbiota transplantation (FMT) has jump-started over the past two decades. Recent technological advancements in sequencing and metabolomics have allowed for better characterization of our intestinal microbial counterparts, triggering a surge of excitement in the fields of mucosal immunology and microbiology. This excitement is well founded, as demonstrated by 90% relapse-free cure rates in FMT treatment for recurrent Clostridioides difficile infections. Growing evidence suggests that in addition to bacterial factors, the host immune response during C. difficile infection greatly influences disease severity. In this review, we discuss recent advancements in understanding the interplay between immune cells and the microbiota and how they may relate to recovery from C. difficile through FMT therapy.