Human milk oligosaccharides and infant health
Human milk oligosaccharides (HMOs) have several biological activities beneficial for health maintenance and disease avoidance in human infants. They function as prebiotics and promote the growth of beneficial bacteria such as bifidobacteria, over pathogens which cannot metabolize HMOs. They act as soluble decoy receptors for pathogens or toxins. The HMOs bind either to the host cell receptor or to the pathogen, blocking the adhesion process and thereby protecting infants from infection. This antiadhesive function has been demonstrated in a large number of pathogens, both bacteria and viruses and this is particularly important in avoiding and limiting gastrointestinal diseases. As cellular response modifiers they impact upon brain development and food allergies.
Mature human milk contains 5–20 g/L of a mixture of oligosaccharides known as human milk oligosaccharide (HMOs). The HMOs are the third most abundant solid component of human milk after lactose and lipids, yet have no nutritional value, since they are not digestible. No other mammal has comparable concentration or diversity of oligosaccharides in milk compared to human milk. However, numerous studies have pointed out that despite having no nutritional value, HMOs play a unique and important role in the development of the human infant.
It is recognised that breastfed infants experience decreased instances of diarrhoea, respiratory infection, urinary tract infection, ear infection, necrotizing enterocolitis and sudden infant death syndrome, compared to their formula-fed counterparts. Furthermore, the microbiome in breastfed neonates tends to be colonized to a lesser extent by infectious species such as Escherichia coli, Clostridium difficile, and Campylobacter jejuni. Many of these protective properties have been attributed to HMOs (1). The HMOs not only provide for protection against pathogens but also hav ...