Breast fed infant have fewer and less severe gastrointestinal and respiratory infections during the first year of life than formula-fed infants. The protective factors in human milk responsible for reduced infections have been the subject of decades of research. The classical protective factors in human milk such as immunoglobulin A, oligosaccharides and lactoferrin, are being investigated. The role of oligosaccharides as protective factors in human milk while not fully defined, can be explained by at least two possible mechanism. First, some oligosaccharides are growth factors for intestinal flora such as Bifidobacterium bifidus, which produce an environment unfavourable for many enteric pathogens. Second, oligosaccharides are potent inhibitors of bacterial adhesion to epithelial surface. Quantitavely, oligosaccharides are the third largest solute in human milk after lactose and fat. Mature milk contains over 15 g/L oligosaccharides compared with only about 9g/L protein. The oligosaccharides content of human milk varies with the duration of lactation, diurnally and with the genetic makeup of the mother. The several laboratories reporting quantitative data on this fraction are in general agreement that is represents over 12 g/L of mature milk and approximately 22 g/L of colostrum. This study aimed to examine the lactose and oligosaccharides content of mature human milk and its possible interactions with nutrition.