Aequival® 3'-SL

3’-sialyllactose (3’-SL) is an acidic human milk oligosaccharide. Findings from preclinical science suggest that 3’-SL can contribute to reducing infections with specific pathogens¹⁻³ and limiting inflammation⁴⁺⁵. Also, 3’-SL can serve as sialic acid donor, thereby potentially contributing to brain development⁶⁺⁷.


  • Acidic HMO containing sialic acid 

  • Sialic acid supports brain development

  • Antipathogenic effects in vitro

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/L. 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’-SL.

3’-SL has also been reported to have anti-inflammatory effects. In animal models for rheumatoid arthritis4 and colitis, 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 brain. Furthermore, human milk 3’-SL levels have recently been shown to be associated with language development in infants. 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.


  1. Laucirica, D. R., Triantis, V., Schoemaker, R., Estes, M. K. & Ramani, S. Milk Oligosaccharides Inhibit Human Rotavirus Infectivity in MA104 Cells. J. Nutr. 147, 1709–1714 (2017).
  2. Duska-McEwen, G., Senft, A. P., Ruetschilling, T. L., Barrett, E. G. & Buck, R. H. Human Milk Oligosaccharides Enhance Innate Immunity to Respiratory Syncytial Virus and Influenza. Food Nutr. Sci. 5, 1387–1398 (2014).
  3. Pandey, R. P. et al. Broad-spectrum neutralization of avian influenza viruses by sialylated human milk oligosaccharides: in vivo assessment of 3′-sialyllactose against H9N2 in chickens. Sci. Rep. 8, 2563 (2018).
  4. Kang, L.-J. et al. 3’-Sialyllactose as an inhibitor of p65 phosphorylation ameliorates the progression of experimental rheumatoid arthritis. Br J Pharmacol Epub, (2018).
  5. Hyder, A. Dietary oligosaccharides attenuate DSS-induced colitis in mice, induce PGlyRP3 expression, and inhibit NF-κB and MEK/ERK signaling. Cell. Immunol. 354, 104144 (2020).
  6. Jacobi, S. K. et al. Dietary Isomers of Sialyllactose Increase Ganglioside Sialic Acid Concentrations in the Corpus Callosum and Cerebellum and Modulate the Colonic Microbiota of Formula-Fed Piglets1–3. J. Nutr. 146, 200–208 (2016).
  7. Cho, S. et al. Human milk 3’-Sialyllactose is positively associated with language development during infancy. Am. J. Clin. Nutr. 1–10 (2021). doi:10.1093/ajcn/nqab103
  8. Soyyilmaz, B. et al. The mean of milk: A review of human milk oligosaccharide concentrations throughout lactation. Nutrients 13, 1–22 (2021).
  9. Martin-Sosa, Samuel, Maria-Jesus, Hueso, M. ; & Pablo. The sialylated fraction of milk oligosaccharides is Partially Responsible for Binding to Enterotoxigenic and Uropathogenic Escherichia coli Human Strains. J. Nutr. 132, 3067–3072 (2002).
  10. Wang, B. Molecular Mechanism Underlying Sialic Acid as an Essential Nutrient for Brain Development and Cognition. Adv. Nutr. 3, 465S–472S (2012).
  11. Schnaar, R. L., Gerardy-Schahn, R. & Hildebrandt, H. Sialic Acids in the Brain: Gangliosides and Polysialic Acid in Nervous System Development, Stability, Disease, and Regeneration. Physiol. Rev. 94, 461–518 (2014).

Get in touch

Contact our experts
Request a sample Subscribe to our newsletter