We now know that human milk contains an array of antimicrobial, anti-inflammatory, immunomodulating and bioactive molecules and compounds that are often multifunctional are adapted to mucosal sites and are not well represented in infant formula milks. When breastfeeding is not practised, reliable data on human milk constituents and their significance to infant health must be available for inclusion into infant formula by industry. Industry continues to improve infant formula with the addition of compounds such as fatty acids, oligosaccharides, nucleotides and lactoferrin. However, there are a myriad of factors that cannot be incorporated into infant formula due to possible differences in compartmentalisation and nutrient molecular form (Picciano 2001).