Abstract IA28: Targeting the microbiome in cancer immunotherapy

Commensal microorganisms colonize barrier surfaces of all multicellular organisms, including those of humans. For more than 500 million years commensal microorganisms and their hosts have coevolved and adapted to each other. As a result, the commensal microbiota affects many immune and nonimmune functions of their hosts, and de facto the two together comprise one metaorganism. The commensal microbiota communicates with the host via biologically active molecules. Recently, it has been reported that microbial imbalance may play a critical role in the development of multiple diseases, such as cancer, autoimmune conditions, and increased susceptibility to infection. The commensal microbiota not only may affect the development, progression, and immune evasion of cancer but has also important effects on the response to cancer immune- and chemotherapy. In my presentation I will discuss some recent analysis of the role of the microbiome in anti-PD1 therapy in melanoma patients, the preliminary data of a fecal microbiota transfer clinical trial (performed at the University of Pittsburgh Cancer Center) in anti-PD1 refractory melanoma patients, as well as mouse data on the effect of dietary fibers on anti-PD1 cancer therapy. Citation Format: Giorgio Trinchieri. Targeting the microbiome in cancer immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr IA28.