Role of gut microbiome on immunotherapy efficacy in melanoma

The gut microbiota is considered a key component in many aspects of cancer pathophysiology and response to therapy. In particular, in recent years intriguing evidences has been emerging regarding the role of the intestinal microbiota in the response to immunotherapy and in promoting the development of adverse events, such as colitis. For this reason, studies are being carried out both on pre-clinical models and on humans to study how to predict the response to immunotherapy through the study of the microbiota or how to improve its clinical response through modulation. Promising data have recently been reported through modulation by probiotics or prebiotics, and in particular by fecal microbiota transplantation. The aim of this review is to analyze the evidence regarding the role of the microbiota in immunotherapy with a particular focus on melanoma.