Antibiotics overuse linked to weight gain, new book says

      |There is new concern over another possible effect of antibiotics: obesity. Dr. Martin Blaser talks to the "CBS This Morning" co-hosts about the link. Blaser is the director of the human micro-biome program at the New York University School of Medicine, and author of the upcoming book, "Missing Microbes: How the Overuse of Antibiotics is Fueling our Modern Plagues."