Utilization by Intestinal Bacteria and Digestibility of Arabino-oligosaccharides In Vitro

Abstract

We investigated the utilization of arabino-oligosaccharides derived from arabinan, which is abundant in side chains of apple pectin, by intestinal bacteria in vitro to clarify the mechanisms of the beneficial effects of apple ingestion on intestinal bacterial flora. Among the test strains, arabino-oligosaccharides that contain more than three units were selectively utilized by Bifidobacterium adolescentis, Bi. longum, and Bacteroides vulgatus. The digestion of arabino-oligosaccharides by artificial digestive juices was investigated in vitro. Arabino-oligosaccharides were not digested by artificial saliva, artificial gastric juice, or artificial pancreatic juice, and only slightly by small intestinal enzymes. These results suggest that arabino-oligosaccharides serve as prebiotics and that the beneficial effects of apple ingestion on intestinal bacterial flora are partly due to apple pectin.