Watch Let Them Eat Dirt: The Hunt for Our Kids' Missing Microbes

Hosted by Good Morning America's Becky Worley, and based on the book by B. Brett Finlay, PhD and Marie-Claire Arrieta, PhD, Let Them Eat Dirt explores exciting new research on the human microbiome and the impact of microbiota on child health and development. See how outdoor play, breastfeeding and vaginal birth are keys to the development of healthy immune systems in infants and young children.