Partial characterization of bifidobacterium breve C50 cell-free whey compounds inducing modifications to the intestinal microflora.

Cell-free whey obtained from milk fermented with Bifidobacterium breve C50 (Bb C50) has been shown to modify the intestinal flora in humans and mice. Previous work showed that no antibiotic-like or barrier effect due to overgrowing bifidobacteria was implied in the microbial modifications. The present study was focused on characterizing the compounds and mechanisms involved.

Identification and synthesis of a trisaccharide produced from lactose by transgalactosylation.

Enzymatic transgalactosylation of lactose by means of Streptococcus thermophilus, subspecies DN-001065, led to a mixture of D-galactose (approximately 4%), D-glucose (approximately 15%), lactose (approximately 51%), minor disaccharides (6%), trisaccharides (approximately 20%) and tetrasaccharides (3%). The major trisaccharide (approximately 16%) was identified by NMR spectroscopy and chemical synthesis as being the known beta-D-galactopyranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->4)-D-glucos e (3'-beta-D-galactopyranosyl-lactose). It was purified from a mixture of peracetylated oligosaccharides by column chromatography followed by deacetylation.