In the past decade, researchers have learned a tremendous amount about how the microbiome influences nearly all aspects of human health, including the immune response, endocrinology, and oncology. While this progress is transforming our understanding of human biology, many more questions remain unanswered. Notably, most studies have focused on the microbiota found in the gut, which contains a large and easily accessible proportion of the microbiome. However, because of this, microbes found in other locations in the body have remained understudied, and their contribution to cancer development and progression remains unclear.
Here, Johanna Joyce and her group will explore extra-intestinal microbiota in the context of brain metastasis (BrM). They recently found that depletion of bacteria via antibiotic treatment alters the development of BrM in a mouse model. The group will further evaluate the impact of bacterial depletion on BrM progression, including by employing germ-free mice to deconvolute the effect of antibiotics on disease progression and will characterize the bacterial and host cell milieu of the BrM tumors through a series of microenvironment-omics and spatial imaging analyses. These studies will help illuminate the burgeoning field of microbiome studies outside of the gut in a cancer context.