3’-sialyllactose (3’-SL) is an acidic human milk oligosaccharide built up of glucose, galactose and sialic acid. The concentration of 3’-SL found in human milk is variable between mothers and by lactation stage. Typically, concentrations of 3’-SL between 0 and 0.7 g/L are reported in mature human milk, with an average of 0.2 g/L⁸. 3’-SL is an important representative of the category of acidic human milk oligosaccharides.
Preclinical studies have shown that 3’-SL has very specific antiviral properties: it inhibits rotavirus1, RSV² and influenza virus³ adhesion and/or infectivity in vitro. Also the bacterium uropathogenic E. coli, which can cause urinary tract infection, was shown to be inhibited by 3’-SL⁹.
3’-SL has also been reported to have anti-inflammatory effects. In animal models for rheumatoid arthritis4 and colitis⁵, 3’-SL was shown to reduce severity of disease and inflammation.
Sialic acid is an essential nutrient in the development of infant brain¹⁰, as a key building block of brain sialoglycans which contribute to proper development, maintenance, and health of the nervous system¹¹. In a study in piglets, 3’-SL supplementation was shown to enrich ganglioside sialic acid in the brain⁶. Furthermore, human milk 3’-SL levels have recently been shown to be associated with language development in infants⁷. These data suggest that 3’-SL can play an important role in brain development early in life, by serving as a sialic acid donor.
Aequival® 3’-SL is structurally identical to the oligosaccharide 3’-SL that is found in human milk. The product is a non-GMO ingredient produced with fermentation technology using lactose as a substrate. Currently, Aequival® 3’-SL is in the final stages of development.