The Microbiome and Obesity (IMAGE) University of Utah Health Caption A beneficial class of bacteria, called Clostridia, prevents mice with a compromised immune system from becoming obese. Credit Charlie Ehlert, University of Utah Health Usage Restrictions With credit 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.