Effects of Administration of Galactooligosaccharides on the Human Faecal Microflora, Stool Weight and Abdominal Sensation

Abstract

The effect of changing the human intestinal microflora by administration of Oligomate-50, which contains 52 per cent galactooligosaccharides and is produced from lactose by the action of β-D-galactosidase (produced by Aspergillus oryzae and Streptococcus thermophillus ), was investigated. Oligomate-50 (0, 4.8, 9.6 or 19.2 g/d) was given orally for 7 d to 12 volunteers in a single-blind cross-over study. Each dose included 0, 2.5, 5.0 or 10.0 g of galactooligosaccharides, respectively. Bifidobacteria were greatly increased following ingestion of galactooligosaccharides and a linear relation was found ( P < 0.05) between the amount of galactooligosaccharides ingested and the number of bifidobacteria per gram of faeces. Lactobacilli were also slightly increased. The ratio of the number of bifidobacteria to the total number of bacteria was significantly increased from 0.26 ± 0.12 to 0.48 ± 0.19 by galactooligosaccharides ingestion. Stool weight and stool frequency after ingestion did not change significantly and no sign of diarrhoea was observed when 10.0 g of galactooligosaccharides was ingested. The results of this study show that galactooligosaccharides are a superior growth-promoting factor for bifidobacteria, and, moreover, have the ability to increase the multiplication of lactobacilli in the human intestinal microflora. Keywords: Galactooligosaccharides; Oligomate-50; Bifidobacteria; Lactobacilli; Intestinal microflora; Faecal microflora.