In contrast, it was found that sialyated human milk oligosaccharides (HMOs) were inversely related with scores in the toddlers, suggesting their possible association with worse cognitive outcomes.
“To our knowledge, no studies on the effects of HMO supplementation on cognition have been performed in humans,” the Danish researchers emphasise, pointing out the importance of their study.
They add: “It might be speculated from these and our findings that early life exposure to 2′FL might be especially important for later cognitive development,” highlighting potential intervention opportunities following further research.
HMOs for future health
The importance of breast milk for an infant’s development and long-term health outcomes has been increasingly established, with previous research suggesting improved immunity during infancy as well as providing protection against disease development in later life. In addition, there have been studies suggesting the importance of HMOs within the milk to influence neurological and behavioural outcomes in the infant.
HMOs are a complex group of carbohydrates with around 200 different structures present within breastmilk, representing its most abundant constituent. Despite these vast numbers, only 10 HMOs make up to 70% of the total concentration. They exhibit a vital function to provide nutrients to the infant’s microbiome, which then exhibits an array of beneficial downstream effects.
Whilst previous animal studies have confirmed links between improved such HMOs and cognitive outcomes in offspring, there are limited studies investigating this effect on neurology within humans. Thereby, the researchers conducted the present longitudinal study investigating whether the human milk 2’-fucosyllactose, 3’-sialyllactose, 6’-sialyllactose, grouped fucosylated HMOs, and grouped sialylated HMOs were associated with better child executive functions at three years of age.
The HMOs were assessed over the first 12 postnatal weeks, with samples of breast milk collected from the mothers at age two, six, and twelve weeks. The included subjects were a sample of 45 healthy Dutch mothers who were exclusively breastfeeding, with an additional 18 partially breastfeeding.
The breast milk samples were analysed using high-performance liquid chromatography-mass spectrometry, whilst resultant executive function questionnaire was completed by the mothers in addition to four behavioural tasks assessing inhibitory control.
Following multiple regression analysis, it was observed that concentrations of 2’fucosyllactoseand grouped fucosulated HMOs were associated with improved executive functions at age three in the studied infants.
Conversely, concentrations of grouped sialyated HMOs were found to be associated with worse outcomes for executive function.
“We found evidence for an association between 2’FL and grouped fucosylated HMOs during the first twelve postnatal weeks and better child executive functions at age three,” the researchers conclude, highlighting that the findings are in line with previous animal studies.
“The microbiota-gut-brain axis is a likely pathway through which HMOs can ultimately exert effects on the brain and behaviour.
“Mainly bifidobacteria benefit from HMOs; for example, Bifidobacterium longum subspecies infantis uses HMOs as metabolic substrates. The exact mechanism of how bifidobacteria can subsequently affect brain development is still unclear. However, bifidobacteria are able to produce short-chain fatty acids, which are able to cross the blood–brain barrier and exert positive effects on the brain,” the report speculates with regards to the observed findings.
The researchers specify the need for larger, longer-term replication studies to further validate the findings, as well as additionally analysing the microbiome to provide insight into the mechanisms of action.
“Fucosylated Human Milk Oligosaccharides during the First 12 Postnatal Weeks Are Associated with Better Executive Functions in Toddlers.”
Yvonne Willemsen, Roseriet Beijers, Fangjie Gu, Alejandro Arias Vasquez, Henk Arie Schols and Carolina de Weerth