Prebiotic branched galacto-oligosaccharides (gos)

The invention relates to galacto-oligosaccharide (GOS) compositions and the use thereof. Provided is the use of a GOS composition comprising branched and linear GOS species having a degree of polymerization (DP) of 3, wherein the branched DP3 GOS species are present in excess of linear DP3 GOS species, for inducing mucin glycan utilization pathways in beneficial gut bacteria in an animal. Preferred compositions comprise the branched DP3 GOS species β-D-Galp-(1-2)-[β-D- Galp-(1-6)-]D-Glcp, β-D-Galp-(1-3)-[β-D-Galp-(1-6)-]D-Glcp β-D-Galp-(1-4)-[β- D-Galp-(1-2)-]D-Glcp, and/or the DP2 GOS species Galβ-1,2-Glc, Gal β-1,3- Glc, Gal-β-1,6-Glc (allolactose) and Gal-β-1,6-Gal. Also provided is a method for providing a GOS composition comprising branched DP3 species and capable of inducing mucin-glycan pathways in beneficial bacteria.