Enzymatic synthesis of β-galactosyl fucose using recombinant bifidobacterial β-galactosidase and its prebiotic effect.

Breast-fed infants have Bifidobacterium-rich gut microbiota compared to infants fed formula. Fucosylated oligosaccharides are the major components of human milk oligosaccharide (HMO) which confer various beneficial effects including prebiotic effect and protection from pathogenic infection on the host. A novel prebiotics was developed using bifidobacterial β-galactosidase and fucose and lactose as substrates. Structure analysis revealed it as β-D-galactopyranosyl-(1 → 3)-O-L-fucopyranose named as β-galactosyl fucose (gal-fuc), which is different from common fucosylated HMOs with α1-2, α1-3, and α1-4 linkages. Among the four Lactobacillus strains examined, all but L. delbrueckii subsp. bilgaricus KCTC 3635 grew better on gal-fuc than on β-GOS. Among the 11 bifidobacterial species examined, all except for B. bifium used gal-fuc as much as GOS. Moreover, the gal-fuc was noticeably better used by Bifidobacterium infantis, the major intestinal bacteria of breast fed infant. Among 15 non-probiotic bacteria, only 4 strains used gal-fuc better than β-GOS. In conclusion, a novel gal-fuc is expected to contribute to beneficial changes of gut microbiota. Graphical abstract A novel form of β-galactosyl fucose with an improved prebiotic effect.