Gut Microbiota Graphic (IMAGE) Penn State Caption The composition of oral microbiota -- the collection of microorganisms, including beneficial bacteria, residing in the mouth -- in two-year-old children may predict their weight gain, according to a new study of over 226 children and their mothers. Credit Penn State Usage Restrictions Credit must be published alongside image. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.