International audience; Non-digestible milk oligosaccharides were proposed as receptor decoys ă for pathogens and as nutrients for beneficial gut commensals like ă bifidobacteria. Bovine milk contains oligosaccharides, some of which are ă structurally identical or similar to those found in human milk. In a ă controlled, randomized double-blinded clinical trial we tested the ă effect of feeding a formula supplemented with a mixture of bovine ă milk-derived oligosaccharides (BMOS) generated from whey permeate, ă containing galacto-oligosaccharides and 3'- and 6'-sialyllactose, and ă the probiotic Bifidobacterium animalis subsp. lactis (B.lactis) strain ă CNCM I-3446. Breastfed infants served as reference group. Compared with ă a non-supplemented control formula, the test formula showed a similar ă tolerability and supported a similar growth in healthy newborns followed ă for 12 weeks. The control, but not the test group, differed from the ă breast-fed reference group by a higher faecal pH and a significantly ă higher diversity of the faecal microbiota. In the test group the ă probiotic B.lactis increased by 100-fold in the stool and was detected ă in all supplemented infants. BMOS stimulated a marked shift to a ă bifidobacterium-dominated faecal microbiota via increases in endogenous ă bifidobacteria (B.longum, B.breve, B.bifidum, B.pseudocatenulatum).