Effects of fructooligosaccharides and their monomeric components on bile salt resistance in three species of bifidobacteria

The influence of fructooligosaccharides (FOS) and their monomeric component s on bile salt resistance of Bifidobacterium breve ATCC 15700, Bif. longum ATCC 15707 and Bif. animalis ATCC 25527 was examined. The neosugars induced fructofuranosidase activities for the degradation of these saccharides. Fo r the three strains tested the growth was identical and bile salts had the same inhibitory effect on growth whatever the carbohydrate used. The surviv al of Bif. breve and Bif. longum, in the presence of glycodeoxycholic acid depended, however, on carbohydrates: the toxic effects of the bile salt cou ld be partly alleviated by the addition of a metabolizable C-source. For Bi f. animalis, the presence of any carbohydrate in the incubation medium did not enhance the viability of the strain. But in the three deconjugating str ains of bifidobacteria studied, the presence of neosugar during the growth led to improved resistance to the bactericidal effect of the bile salt comp ared with the monomeric components of these neosugars (glucose and fructose ).