MUC2 and inflammatory bowel disease: Intestinal mucus, encoded by Muc genes (up-regulated due to B. breve UCC2003 in this study), plays a crucial role in colonic protection via formation of a physical barrier between the gut lumen and IECs, and deficiencies in MUC-2 have been linked with experimental colitis and increased inflammation in patients with inflammatory bowel disease (Shirazi et al., 2000, Van der Sluis et al., 2006).