The science journalist draws on ancient food traditions and the latest research on healthy gut maintenance to explain the role of the microbiome and how to adapt a diet to promote optimal microbiome balance.

Meet the 300 trillion microorganisms that keep us healthy—and the traditional foods that nourish them. Probiotic yogurt and other "gut-friendly" foods line supermarket shelves. But what's the best way to feed our all-important microbiome—and what exactly is a microbiome, anyway? Science journalist Katherine Harmon Courage investigates these questions, presenting a deep dive into the ancient and artisanal foods that feed a healthy gut, as well as the cutting-edge science that's catching up to these time-honored traditions.