Fecal microbiota transplantation for the treatment of intestinal and extra‐intestinal diseases: Mechanism basis, clinical application, and potential prospect

To review the theoretical basis and therapeutic effects of fecal microbiota transplantation (FMT) in various diseases in animal experiments and clinical studies, as well as the limitations and current standards of FMT application. PubMed and Web of Science databases were searched for articles published only in English between 1975 and 2023 on reliable results of animal experiments and clinical treatment of FMT. The properties of the gut microbiota and its interactions with the host metabolism are critical to human health, and microbiome disturbance is closely associated with human intestinal and extra‐intestinal diseases. Therefore, therapeutic tools targeting on the modulation of gut microbiota have attracted increasing attention, among which FMT represents the most widely studied intervention strategy. This review gathered and summarized application of FMT in intestinal diseases, metabolic diseases, hypertension, cancer, nervous system diseases and arthritis, and elaborated the beneficial effects that can be achieved by altering the microbiota with FMT and the mechanisms of action. In addition, the potential risks and side effects of FMT approach are discussed, as well as current efforts to standardize the development of FMT. Through a systemic review of the outcome and mechanism of FMT in the treatment of intestinal diseases and extra‐intestinal diseases, we aimed to provide a theoretical basis for the construction of an optimized FMT framework, so as to better exert its application prospects.