Bile acids, classically known for their roles in facilitating lipid digestion and absorption, have become appreciated as a family of enterocrine hormones that regulate many aspects of intestinal physiology, including epithelial barrier permeability, immune function, apoptosis, and inflammation. Dysregulation of intestinal epithelial barrier function is closely associated with the development of several diseases, most notably inflammatory bowel disease (IBD), a condition where compromised epithelial barrier function allows the contact of luminal contents with mucosal immune cells, thereby promoting inflammation. Our research focusses on understanding the roles that bile acids play in regulating intestinal epithelial barrier function, how they contribute to disease pathogenesis and, ultimately how they can be targeted for the development of new treatments. Ursodeoxycholic acid (UDCA) is a secondary bile acid normally produced by bacterial metabolism in the colon. UDCA has a long history as a safe and effective therapeutic, first in Traditional Chinese Medicine and later in Western medicine as a treatment for cholestatic liver diseases. Based on its known cytoprotective and anti-inflammatory actions, we have investigated the role of UDCA in regulation of intestinal barrier function and its potential for development as a new approach to treat IBD.