Effect of galacto-oligosaccharide supplementation on human faecal microflora and on survival and persistence of Bifidobacterium lactis Bb-12 in the gastrointestinal tract

Galacto-oligosaccharides (GOS) are considered. to have bifidogenic properti es in humans. To study the effect of GOS-containing syrup (60% GOS) alone o r together with the probiotic strain Bifidobacterium lactis Bb-12 on select ed components of the faecal flora, and the effect of GOS supplementation on colonisation of B. lactis Bb-12, a feeding trial on 30 healthy volunteers was performed. Mean numbers of bifidobacteria increased slightly in all stu dy groups during the feeding period. Isolates having the identical RAPD gen otype with B. lactis Bb-12 were detected in high numbers in the Bb-12 group and in the GOS-containing syrup + Bb-12 group indicating a good survival o f B. lactis Bb-12 through the gastrointestinal tract. No differences in the prevalence or numbers of isolates with B. lactis Bb-12 genotype could be o bserved between groups suggesting that GOS-containing syrup did not enhance the survival or persistence of B. lactis Bb-12 in the gut. (C) 2001 Elsevi er Science Ltd. All rights reserved.