Investigation of B. frag Evolution in Healthy People (image) Cell Press Share Print E-Mail Caption This graphical abstract demonstrates how Bacteroides fragilis adapts via mutation in healthy people. Credit Zhao et al./Cell Host & Microbe Usage Restrictions Credit Required. Share Print E-Mail 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.