Fecal Microbiota Transplantation: Indications, Methods, and Challenges.

Over the past two decades, as the importance of gut microbiota to human health has become widely known, attempts have been made to treat diseases by correcting dysbiosis of gut microbiota through fecal microbiota transplantation (FMT). Apart from current knowledge of gut microbiota, FMT to treat disease has a long history, from the treatment of food poisoning in the fourth century to the treatment of Clostridioides difficile infections in the twentieth century. In 2013, FMT was recognized as a standard treatment for recurrent C. difficile because it consistently showed high efficacy. Though recurrent C. difficile is the only disease internationally recognized for FMT efficacy, FMT has been tested for other diseases and shown some promising preliminary results. Different FMT methods have been developed using various formulations and administration routes. Despite advances in FMT, some issues remain to be resolved, such as donor screening, manufacturing protocols, and unknown components in the fecal microbiota. In this review, we discuss the mechanisms, clinical indications, methods, and challenges of current FMT. We also discuss the development of alternative therapies to overcome the challenges of FMT.