Abstract: Gut microbiota helps in maintaining a healthy balance within the microecosystem of the host, and the occurrence of dysbio-sis has been linked to tumorigenesis. Specific commensal microbes and their metabolites have the potential to inhibit tumorigenesis. Moreover, gut microbiota plays an important role in the maturation and regulation of both the innate and adaptive immune systems. This microbe population,which lives in the intestines, enhances the antitumor effects of alkylating agents, Toll-like receptor agonists, immune checkpoint inhibitors, and adoptive cellular immunotherapy. Furthermore, gut microbiota also affects the antitumor immune response by regulating the differentiation and function of tumor-infiltrating myeloid cells, the reprogramming of which may be an ide -al method for cancer therapy. The manipulation of gut microbiota represents a new strategy for cancer therapy. However, clinical appli -cation of gut microbiota still poses many problems.