Intratumoral microbiota: new frontiers in tumor immunity

Abstract Microbiota–host interactions are a hot topic of research because of their important role in regulating the malignant transformation of cancer cells and cancer-related immunity. The role of gut microbiota, oral microbiota and skin microbiota in cancer progression has been extensively studied. However, intratumoral microbiota is a recently discovered topic of research that is still in its infancy. This review focuses on the impact of the intratumoral microbiota on cancer immune responses and highlights how the intratumoral microbiota modulates innate and adaptive immunity to potentially impact tumor immunotherapy in the hope that it will inspire potential ideas for the application of immunotherapy in the treatment of tumors.