A new report, published at the end of August 2018, brings together all the major clinical trials and studies into oligosaccharides in human milk (HMOs) from across Europe from 1990 to date. The addition of some HMOs to infant formula were also included in the review.
The number of HMOs in mother’s milk is a dynamic process as it changes over time. Many factors, such as duration of lactation, environment and genetic factors influence the number of HMOs. They may support immune function development and provide protection against infectious diseases directly through the interaction of the gut epithelial cells or indirectly through the modulation of the gut microbiota, including the stimulation of the bifidobacteria. The limited clinical data suggest that the addition of HMOs to infant formula seems to be safe and well tolerated, inducing normal growth and suggesting a trend towards health benefits.
Breastmilk is the natural and ideal food for infants, and the composition of breastmilk is unique. Aside from nutrients for the infant’s healthy growth and development, it contains thousands of bioactive substances including HMOs, which are non-digestible carbohydrates. Although they have little nutritional value for the infant, HMOs are the third largest solid component in human milk after lactose and lipids. The difference in HMO content of human milk and cow’s milk, and therefore cow’s milk-based infant formula, is likely to explain, in part, the differences in health outcomes between formula and breastfed infants.
It is only recently that scientists and industry have been able to produce the first HMOs structurally identical to those in human milk. HMOs resist cold and heat and are not affected by pasteurization and freeze-drying.
In 2015, the European Food Safety Authority concluded that two important strains of HMOs – 2’-FL and LNnT are safe to include in infant formula.
The new report looks particularly at these two strains of HMO through preclinical and observational studies, looking in particular at modification of the intestinal microbiota, anti-adhesive antimicrobials, modulation of the intestinal epithelial cell response, immune modulation, brain development and gut adaption.
The report notes that HMOs act as soluble decoy receptors that block the attachment of specific viral, bacterial or protozoan parasite pathogens to epithelial cell surface sugars, which may help prevent infectious diseases in the gut, respiratory and urinary tracts. In addition, HMOs alter host epithelial and immune cell responses with potential benefits for the neonate, beyond protection against infectious diseases.
The addition of HMOs is a step forward in bringing formula feeding closer to mother’s milk. More prospective, randomized trials in infants comparing formulas with and without HMOs are still needed to evaluate the clinical effects of supplementation.
Human Milk Oligosaccharides: 2'-Fucosyllactose (2'-FL) and Lacto-N-Neotetraose (LNnT) in Infant Formula. Vandenplas Y, Berger B, Carnielli VP, Ksiazyk J, Lagström H, Sanchez Luna M, Migacheva N, Mosselmans JM, Picaud JC, Possner M, Singhal A, Wabitsch M. Nutrients (2018 )