A CRITICAL ANALYSIS OF TOTAL SIALIC-ACID AND SIALOGLYCOCONJUGATE CONTENTS OF BOVINE MILK-BASED INFANT FORMULAS

Background: Several infant formulas are bovine milk-based products. Ma ture bovine milk has a very low sialoglycoconjugate content compared w ith human milk from the first phases of lactation. Methods: The presen t study was undertaken to determine total sialic acid and oligosacchar ide, glycoprotein, and ganglioside sialic acid contents of bovine milk -based formulas. Results: Starter formulas, designed for the first day s/weeks after birth, have very similar sialic acid contents (233-266 m g/L fresh milk). We found more oligosaccharide-bound sialic acids (167 -174 mg/L fresh milk) than those bound to proteins (53-84 mg/L fresh m ilk) in these formulas. The ganglioside sialic acid contents of starte r formulas (952-1135 mu g/L fresh milk) vary slightly from formula to formula. However, all the above-mentioned contents are lower than in h uman colostrum or transitional milk. Conclusions: Infants fed starter formulas have total sialic acid and oligosaccharide, glycoprotein, and ganglioside sialic acid intakes of 36, 28, 50, and 20%, respectively, of those fed human colostrum or transitional milk. By contrast, follo w-on formulas, used from 4 to 5 months of age, provide total sialic ac id and oligosaccharide, glycoprotein, and ganglioside sialic acid cont ents similar to those furnished by mature human milk. Since the refere nce standard for optimal nutrition in the early months of infancy is h uman milk, a supplementation with sialic acid-containing glycoconjugat es of infant formulas recomended for the first daysafter delivery coul d be advisable when breast-feeding is not possible.