Role of microbiome in cancer immunotherapy

Cancer is a primary cause of death globally. Surgery, chemotherapy, and radiotherapy were the most common types of cancer treatment available for a long time but not resolutive. To date, significant advancements in cancer immunotherapy has become of huge interest because of its promise for revolutionizing tumor therapy, with reduced risk of adverse events compared to the conventional therapies. Immunotherapy is a treatment that activates or suppresses the host-immune responses. However, an intricate network of dynamics, involving host and environmental factor can influence the individual immune response. Between them, the “microbiome” has currently acquired growing consideration because of its emerging role as modulator of the immune response. In this context, the potential therapeutic utility of directly manipulating commensal microbiota could be an approach to enhance the efficacy of cancer immunotherapy. In that connection, it is important to discuss how the microbiota will reshape our approach to cancer immunotherapy, introducing the concept of “holobiont.” Finally, the full comprehension of the holobiont as the privileged biological unit to study the immune response urges the need of an approach capable of encompassing the “whole eco-immune system.”