Colonic Adaptation Postileal Resection: Bile Acid Absorption in an Ileal Resection Mouse Model.

Background: Adaptation of the small intestine and/or colon significantly impacts the prognosis of short bowel syndrome. This study investigated colonic adaptation in a mouse model of ileal resection, with a focus on bile acid absorption. Methods: The ileal resection mouse model (ileal resection group, 8-10-week-old male C57BL/6J mice) was created by resecting 15 cm of the ileum, corresponding to approximately 50% of the small intestine, while preserving the cecum. The sham group underwent intestinal transection and reanastomosis at a site matched in distance from the ligament of Treitz to that used for the resection group. Postoperatively, between Days 1-7 and 7-14, mice received the elemental diet ELENTAL® (0.5 kcal/mL) and a standard solid diet ad libitum, respectively. The mice were euthanized on Day 14. We assessed postoperative body weight; histopathological characteristics of the colon; bile acid metabolism-related gene expression, including Results: Significantly lower changes in body weight and longer colon length were observed in the ileal resection group than in the sham group; however, no histological differences were observed in colonic mucosal height. Furthermore, a significantly increased Conclusion: Our results suggest a colonic adaptation to prevent impairment of bile acid absorption following ileal resection.