Application and prospects of fecal microbiota transplantation in cancer therapy.

As the largest community of commensal microorganisms in the human body, the gut microbiota-through its structural and functional imbalances-participates in the entire process of tumor initiation and progression, and profoundly influences the efficacy and safety of conventional anticancer regimens, including chemotherapy and immunotherapy. Fecal microbiota transplantation (FMT) offers a novel biological strategy for cancer treatment by reestablishing the ecological balance of the host gut microbiota. This review systematically integrates the basic theory, clinical practice, technical optimization, epidemiological features, current challenges, and future directions of FMT in oncology. It elaborates on how FMT modulates the tumor microenvironment via core mechanisms such as immune regulation, metabolic reprogramming, and intestinal barrier repair, and shows potential value in enhancing immunotherapy responses, improving chemotherapy tolerance, and alleviating treatment-related complications across various malignancies, including colorectal cancer, liver cancer, and melanoma. Meanwhile, the article outlines practical difficulties regarding donor screening, formulation standardization, ethical oversight, and long-term safety evaluation of FMT, and looks ahead to the development of precision FMT, synthetic microbial consortia, integration of multi-omics technologies, and combination treatment paradigms. The aim is to provide a comprehensive, systematic, and academically in-depth reference for the translational and basic research of FMT in precision cancer therapy.