The next blockbuster drug may already be in production by bacteria within your body. Bacteria produce unique chemical compounds that are bioactive and may have great therapeutic potential, but this chemical space has largely not been mined. Empress Therapeutics, a Flagship Pioneering company, is searching for such molecules by exploring the genes of bacteria that live in the human body to search for the molecules they produce and identify compelling drug candidates. Since its founding in 2020, the company has already identified 15 novel candidates. We spoke to Sabrina Yang, chief innovation officer for Empress and a principal at Flagship Pioneering, about how exploring the bacterial metagenome in the human body can point the way to the next blockbuster drug, the role AI plays in its platform, and how this approach can accelerate the time and reduce the cost of drug development.