Justin Sonnenburg, PhD, is a professor in the Department of Microbiology and Immunology at the Stanford University School of Medicine, where he studies the gut microbiota in health and disease and co-directs the Center for Human Microbiome Studies. He and his wife Erica, are the authors of the book The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-Term Health. Their laboratory at Stanford develops and employs diverse technologies to understand basic principles that govern interactions within the intestinal microbiota and between the microbiota and the host. An ongoing objective of the research program is to devise and implement innovative strategies to prevent and treat disease in humans via the gut microbiota. Current pursuits include genetic engineering commensal bacteria to enable therapeutic delivery within the gut, as well as understanding the health impact of microbiome change that has occurred during industrialization. Justin conducted his Ph.D. in Biomedical Sciences at the University of California, San Diego in the laboratory of Ajit Varki. His postdoctoral work was conducted at Washington University in Saint Louis, Missouri in the laboratory of Jeffrey Gordon. He has received an NIH Director’s New Innovator Award and Pioneer Award. He serves on several scientific advisory boards and is a co-founder of Interface Biosciences.