Oligosaccharides are the third most abundant component in human milk. It is widely accepted that they play several important protective, physiological, and biological roles including selective growth stimulation for beneficial gut microbiota, inhibition of pathogen adhesion and immune-modulation. However, until recently, very few commercial products on the market capitalized on these functions. This is mainly because the quantities of human milk oligosaccharides required for clinical trials have been unavailable. Recently, clinical studies have tested the potential beneficial effects of feeding infants formula containing 2’-fucosylactose, the most abundant HMO in human milk. These studies have opened this field for further well-designed studies which are required to fully understand the role of HMO. However, one of the most striking features of human milk is its diversity of oligosaccharides with over 150 identified to date. It may be that a mixture of oligosaccharides is even more beneficial to the infant than a single structure. For this reason, the milk of domestic animals has become a focal point in recent years as an alternative source of complex oligosaccharides with associated biological activity. Bovine milk is an ideal candidate, given its wide availability and its use in so many regularly consumed dairy products. The carbohydrate fraction of bovine milk is divided into lactose, free oligosaccharides and bound glycans or glycoconjugates. This presentation will focus specifically on free oligosaccharides and glycosylated bovine milk proteins and the biological roles associated with such structures. A major area of interest is the effect of milk glycans on host-microbial interactions in the gut. For instance, glycosylated components in milk are known to alter intestinal glycosylation, which in turn contributes to early immune development and maturation of the newborn intestinal tract. Strategies to increase the colonisation of infant-associated bifidobacteria have been extensively investigated in recent years with promising results.