One of the hottest science topics today is the microbiome — the microbial population that may rule your metabolism, immune system, and mood. This month, Dr. Moriarty chats with Dr. Allyson Byrd from Genentech. They discuss the importance of a healthy microbiome and what sorts of medical data can be gained from understanding microbiota better. Dr. Byrd’s work could someday help doctors design smarter treatments for all sorts of diseases aggravated by unhealthy microbes. She even shows off a new flushable device designed to make testing at home easier.