The Role of the Microbiome in Cancer Initiation and Progression: How Microbes and Cancer Cells Utilize Excess Energy and Promote One Another’s Growth

Purpose of Review: We use an ecological lens to understand how microbes and cancer cells coevolve inside the ecosystems of our bodies. We describe how microbe-cancer cell interactions contribute to cancer progression, including cooperation between microbes and cancer cells. We discuss the role of the immune system in preventing this apparent ‘collusion’ and describe how microbe-cancer cell interactions lead to opportunities and challenges in treating cancer. Recent Findings: Microbiota influence many aspects of our health including our cancer risk. Since both microbes and cancer cells rely on incoming resources for their survival and replication, excess energy and nutrient input from the host can play a role in cancer initiation and progression. Summary: Certain microbes enhance cancer cell fitness by promoting proliferation and protecting cancer cells from the immune system. How diet influences these interactions remains largely unknown but recent evidence suggests a role for nutrients across the cancer continuum.