In vitro comparative evaluation of the impact of lacto-N-biose I, a major building block of human milk oligosaccharides, on the fecal microbiota of infants.

Lacto-N-biose I (LNB) is a potential factor for the selective growth of bifidobacteria. We previously reported that the species of bifidobacteria predominant in infant intestines might use LNB. We aimed to assess the prebiotic properties of LNB in comparison to other oligosaccharides using an in vitro fermentation system. Stool samples from formula-fed infants were inoculated with media containing a sole carbon source of 1% LNB, lactulose, raffinose, galactooligosaccharide, or mannanoligosaccharides. LNB significantly increased the total bifidobacterial population similarly to other oligosaccharides, but induced a significantly higher level of Bifidobacterium bifidum in comparison to other oligosaccharides. Furthermore, significantly lower concentrations of lactic acid and significantly higher concentrations of acetic acid were produced in cultures containing LNB in comparison to cultures that contained other oligosaccharides. In conclusion, LNB might have a beneficial effect on the fecal microbiota of infants and is a potential prebiotic for application in infant foods or supplements.