The Gut Microbiome and Immune Checkpoint Inhibitor Therapy in Solid Tumors

The microbiome has the potential to serve as a robust biomarker of clinical response to immunotherapy. Additionally, microbial manipulation, through diet, exercise, prebiotics, probiotics, or microbially-derived metabolites, may prove to be beneficial in promoting anti-tumor immune responses. However, large prospective studies in humans with longitudinal sample collection and standardized methods are needed to understand how microbiota and their byproducts affect cancer therapies, particularly among patients undergoing identical therapy but experiencing different outcomes. The proposed observational study builds upon these hypotheses by proposing a large cohort design to further assess the associations between the gut microbiota (composition and function), host immune system, and ICI treatment efficacy across multiple cancer types.