Description:Members of the Enterobacteriaceae family of bacteria are often overrepresented in inflammatory bowel disease (IBD). Bile acids (BAs) are cholesterol derivatives that are known to affect the growth of potentially pathogenic commensals (pathobionts), including those from the Enterobacteriaceae family. Furthermore, BAs are often increased in the colonic lumen of IBD patients, including patients with Crohn’s disease (CD). Here, we investigated whether bile acids influence gut colonization by Enterobacteriaceae.