Breast milk contains many antimicrobial and immunomodulatory molecules such as immunoglobulins, antimicrobial peptides, and fatty acids that cow milk lacks, a study has revealed.
According to researchers, breast milk contains more glycerol monolaurate (GML) and has more antimicrobial compounds (for eg. Staphylococcus aureus, Bacillus subtilis, Clostridium perfringens, Escherichia coli) than cows' milk and infant formula.
The study published in the journal Scientific Reports revealed that human milk contained 3,000 µg/ml of GML compared to 150 μg/ml in cow milk and none in infant formula.
National Jewish Health's Professor and lead author Donald Leung said high levels of GML were unique to human milk and inhibited the growth of pathogenic bacteria.
"While antibiotics can fight bacterial infections in infants, they kill the beneficial bacteria along with the pathogenic ones. However, GML is much more selective and fights only the pathogenic bacteria while allowing beneficial species to thrive," the University of Iowa Professor and co-author Patrick Schlievert explained.
The researcher continued to say that GML held great promise as a potential additive to cows' milk and infant formula to promote babies' health across the world.
The study also suggested that breast milk lost its antimicrobial activity against Staphylococcus aureus when GML removed from it and cow milk became antimicrobial when scientists added GML to it.
The findings revealed that GML inhibited inflammation in epithelial cells lining the gut and other mucosal surfaces. Inflammation damages epithelial cells and contributes to susceptibility to both bacterial and viral infections.
"Positive effects of human milk appear to be due to the presence of GML combined with other known and unknown factors, and further researches can determine whether or not supplementation of cows' milk and commercial infant formula with GML will be beneficial," the researcher concluded.