PROBLEM TO BE SOLVED: To provide a food or a livestock feed for the improvement of the intestinal tract function that exerts an improvement effect on intestinal tract function on the basis of the improvement in tissue of epithelial cells and the villus tips in the small intestine for good absorption of nutrients, healthy growth in the growth period of human being and livestock and improvement of health condition of such animals.SOLUTION: The food or livestock feed contains &bgr；-1,4-mannobiose which has an action capable of increasing an epithelial cell area or an epithelial cell number of intestinal tract tissue and causing the increase in protuberant cells and cell aggregates at the villus tip of the duodenum, jejunum or ileum. The &bgr；-1,4-mannobiose is derived from copra meal, palm kernel meal and coffee grounds and is produced by the action of mannan catabolic enzyme on a natural food containing mannan.【課題】栄養素の健全な吸収、人や畜産動物の成長期における健全な生育や、またこれらの動物の健康状態の改善のため、上皮細胞や小腸内絨毛先端部の組織改善をベースに腸管機能の改善効果を発揮する腸管機能改善用食品又は飼料を提供する。【解決手段】腸管組織の上皮細胞面積又は上皮細胞数が増加することや、十二指腸、空腸又は回腸の絨毛先端部で、隆起細胞及び細胞塊の増加を引き起こすことができる作用を持つ、β－１，４－マンノビオースを含有する食品又は飼料とする。β－１，４－マンノビオースはコプラミール、パーム核ミール、コーヒー粕由来であり、マンナン含有天然物にマンナン分解酵素を作用させて生成したものである。【選択図】図３
