Martin J. Blaser, MD, is the author of Missing Microbes: How the Overuse of Antibiotics Is Fueling Our Modern Plagues. He has studied the role of bacteria in human disease for more than thirty years. Blaser is the director of the Human Microbiome Program at New York University, and was formerly the president of the Infectious Diseases Society of America, and has had major advisory roles at the National Institutes of Health. He lives in New York City.