The immune system of an infant is immature at birth. This makes the newborn, and particularly the premature baby, relatively susceptible to bacterial and viral infections. The immune system gradually matures during infancy15. Exposure to microbes in early life seems to play a role in the normal development of the gut flora and therefore the maturation of the immune system16. A number of bioactive components are involved in this complex process.
Over the past decade, a lot of research has focused on nutrients and their role within the establishment of a diverse gut flora, and subsequently their impact on maturation of the new-born’s immune system.
Studies have shown that galacto-oligosaccharides (GOS) are able to positively influence the microflora in the gut by stimulating the growth of healthy bifidobacteria and lactobacilli17,18. Breakdown of GOS by these gut bacteria results in the formation of short chain fatty acids (SCFA), thereby decreasing the pH and contributing to a healthy gut19. Lactoferrin is a bioactive protein with described anti-microbial properties20,21.
Human Milk Oligosaccharides (HMO)
HMOs are complex sugars which have been described to have a positive effect on the beneficial gut flora22. The most abundant HMO found in breast milk is 2’-fucosyllactose (2’-FL). Next to its bifidogenic activity23, 2’-FL has also been described to make a positive contribution to the immune system as it has the capacity to reduce the risk of infections24,25 and allergy26,27
When the protein fraction in milk or formula is intact, it can act as an allergen and cause allergic reactions in at-risk or cow’s milk allergic infants. By hydrolysing the protein, the allergenicity is reduced depending on the degree of hydrolysis. For healthy infants that are not suffering from allergies, hydrolysed proteins could also be beneficial because they are ‘pre-digested’ and may therefore be easier for a new-born to digest28-31.