This invention relates to the use of an oligosaccharide selected from the group consisting of lacto-N-tetraose, lacto-N-neotetraose, lacto-N-hexaose, lacto-N-neohexaose, para-lacto-N-hexaose, para-lacto-N-neohexaose, lacto-N-octaose, lacto-N-neooctaose, iso-lacto-N-octaose, para-lacto-N-octaose and lacto-N-decaose in the manufacture of a medicament for infants or a therapeutic nutritional composition for infants for modulating immune responses in a neonatal infant. The invention extends to the use of such an oligosaccharide for modulating the immune system of a neonatal infant to promote the development in the first few weeks of the life of the infant of a beneficial intestinal microbiota comparable with that found in breast fed infants and for reducing the risk of subsequent development of allergy in the infant.
