THE EFFECTS OF TRANSGALACTOSYLATED OLIGOSACCHARIDES ON GUT FLORA METABOLISM IN RATS ASSOCIATED WITH A HUMAN FECAL MICROFLORA

The effect on various caecal bacteria and their metabolic activities o f feeding diet containing transgalactosylated oligosaccharides (TOS) w ith or without Bifidobacterium breve (administered in the drinking wat er) was investigated in rats colonized with a human faecal microflora. TOS (5% w/w in diet) or TOS plus B. breve, given for 4 weeks, induced increases in caecal concentration of total anaerobic bacteria, lactob acilli and bifidobacteria, and decreases in numbers of enterobacteria. Caecal pH was significantly reduced by feeding TOS, as were the activ ities of beta-glucuronidase and nitrate reductase. In contrast, beta-g lucosidase activity was increased in TOS-fed rats. Dietary TOS was als o associated with decreased conversion, by caecal contents, of the die tary carcinogen 2-amino-3-methyl-3H-imidazo[4, 5-f] quinoline (IQ) to its genotoxic 7-hydroxy derivative.