The research from UVA’s Melanie Rutkowski, Ph.D., and colleagues helps explain how the gut microbiome—the collection of microorganisms that live in and on our intestines—plays a role in the spread of hormone receptor-positive (HR+) breast cancer. The work adds to a growing understanding of the far-reaching influence of the microbiome in both disease and maintaining good health.

“We found that an unhealthy gut microbiome loses the ability to regulate the composition of bile acids, potent signaling molecules that, when not properly regulated, can cause havoc on your health, metabolism and the immune system. This creates an environment throughout the body that favors breast tumor metastasis,” Rutkowski said.