Mechanistic Roles of Gut Microbiota Regulation in Cancer Immunotherapy

Abstract

Cancer immunotherapy has become an important approach in the treatment of many malignant tumors, especially with the development of immune checkpoint inhibitors. However, clinical responses vary substantially, and a considerable number of patients gain limited benefits or develop resistance during treatment. Recent evidence indicates that the gut microbiota is a crucial factor underlying such heterogeneous therapeutic outcomes. This paper focuses on the role of gut microbiota in tumor immunotherapy by summarizing the latest findings regarding its involvement in immune regulation. The gut microbiota modulates immune system development, reshapes the tumor microenvironment and affects responses to immune checkpoint blockade. Specific microbial communities correlate with enhanced anti-tumor immunity and improved therapeutic efficacy, whereas microbial dysbiosis induces immunosuppression and attenuates treatment effects. Microbial metabolites also act as key mediators linking the gut microbiota and host immunity. Potential strategies to improve immunotherapeutic outcomes via microbiota modulation are also outlined, including fecal microbiota transplantation, probiotic supplementation and dietary intervention. Elucidating gut microbiota-immune interactions holds great promise for optimizing effective and personalized cancer immunotherapy strategies.