Salivary HMOs account for approximately 13% of total HMOs, of which 3 '- sialyllactulose (3' - SL) is the simplest, accounting for about 2%, and has been widely proven to have prebiotic functions. Salivary acid is an important component of neurons, and 3 '- SL particularly supports infant brain development by providing sialic acid. Salivary acid HMOs such as 3-SL can inhibit Helicobacter pylori adhesion to gastrointestinal epithelial cells.

3 '- SL has been approved for use in various foods and beverages such as infant formula, beverages, dairy products, etc. in the United States. The EU can also apply 3 '- SL to dietary supplements, formula foods for special medical purposes, and milk based beverages or similar products intended solely for young children.