Multiple studies have now confirmed a dramatic link between the health of our microbiome—the trillions of bacteria that live in our digestive tract—and our likelihood of getting devastating viral illnesses like COVID-19. Low-fiber diets, limited exposure to nature, and overzealous use of pharmaceuticals have messed up our microbiome, making many of us more susceptible to viruses than we naturally should be. But the good news is that unlike our genes, our microbiome is constantly evolving, offering a pathway back to health for those who are suffering, and proven protection for those who want to stay well. In , Dr. Robynne Chutkan explains this groundbreaking research and offers a prescriptive plan for anyone trying to avoid or recover from a viral illness to rehab their gut microbes and restore their health. In this powerful road map to strengthening the gut-immune system, Chutkan gives practical advice for balancing both your internal and external environment by optimizing diet, exercise, sleep, and time outdoors to boost your host defenses and overall health. includes: Complete with inspiring stories from Dr. Chutkan’s own patients who have battled COVID-19, will empower readers to jump-start their journey toward healing.