Breast-feeding is the golden standard for infant feeding. However, the majority of a few week old infants are fed with a second choice infant feeding, cow's milk based formula. Amongst the multiple differences between human and cow's milk regards the development of the gastro-intestinal flora: the flora of the breast-fed infant being richer in bifidobacteria and lactobacilli. Both species are known to be potentially beneficial for the health of the host. The absence of oligosaccharides, the third largest component in human milk, in cow's milk is likely to account for the differences in colonic flora. The oligosaccharide content and concentration in breast milk is - just as for the other macronutrients - a dynamic process, making it impossible for industry to mimic nature. However, if the composition cannot be mimicked, the effect and function can be imitated. The addition of two oligosaccharides, galacto-oligosaccharides and inulin, to cow's milk based infant formula has been shown to have a bifidogenic effect, and to stimulate the growth of bifidi and lactobacilli. In conclusion, the addition of oligosaccharides to cow's milk based infant formula brings this alternative, second choice infant feeding one step closer to the golden standard of human milk. But, prolonged breast-feeding should still be promoted with maximum effort.