FAS-Deficient Mice (IMAGE) Washington University School of Medicine Caption In mice without the key enzyme, fatty acid synthase, bad bacteria invade the colon and the small intestine, which creates the inflammation underlying insulin resistance and diabetes. In the mouse colon above, a protein (shown in red) that makes up the protective membrane in the gut is not functioning properly. Credit Washington University School of Medicine Usage Restrictions None 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.