Cinnamon Oil (IMAGE) Washington State University Caption Cinnamomum cassia oil has been shown to kill certain strains of E. coli bacteria. Credit Robert Hubner, WSU Photo Services 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.