Effects of Soybean Oligosaccharides on Human Faecal Flora

Abstract

A purified stachyose and raffinose fraction of soybean oligosaccharides was fermented in vitro by Bifidobacterium spp., although not B. bifidum, and fermented to a limited degree by Lactobacillus salivarius , Mitsuokella multiacida and the Bacteroides fragilis group, but was not fermented by other bacteria. Six healthy adult males (28 - 48 yr of age) ingested 10 g of soybean oligosaccharides extract (SOE; 23 per cent stachyose and 7 per cent raffinose) daily independently or in combination with 6 x 10 9 colony forming units (c.f.u.) of B. longum 105 for 3 wk. During ingestion of SOE, the number of bifidobacteria increased significantly. Keywords: Soybean oligosaccharides; Stachyose; Raffinose; Faecal microflora; Bifidobacteria.