Abstract
The investigational scale of the gut microbiome is expanding rapidly. In 2018, the intersection of gut microbiota and immuno-oncology received much attention. While the impact of gut microbiota on the immune system was already established, the year received an exponential expansion of microbiome's role in the immunotherapy setting. The microbiome research pipeline is ripe for large-scale, prospective trials. Working knowledge of immune-based cancer treatments, heterogeneity in their responses and resistance mechanisms, relevant immunological and microbiological pathways and potential for gut microbiome in enhancing the responses, is critical.