Affinity Chromatographic Identification and Quantitation of Blood Group A‐Active Oligosaccharides in Human Milk and Feces of Breast‐Fed Infants

Abstract

SummaryThe finding of large quantities of blood group A‐active oligosaccharides in the feces of a blood group A breast‐fed infant motivated a search for the origin of these compounds. Using an affinity chromatographic technique, the nature of A‐active oligosaccharides in human milk is demonstrated. The amounts of A‐active tetrasac‐charide (A‐tetra) and the Lewis b‐active lacto‐N‐difucohexaose I (LND‐I) varied between 19–375 mg/L for A‐tetra and 14–710 mg/L for LND‐I. Using the same technique, the amounts of A‐tetra and LND‐I in milk samples from five women of different blood groups were compared with those in the feces of their breast‐fed infants. The A‐tetra was present only in feces from infants of blood group A or AB mothers and the amount per 24 h corresponded roughly to that in a 1‐L portion of milk. One of the milk samples was also analyzed for the presence of larger A‐active oligosaccharides (A‐pentasaccha‐ride, A‐hexasaccharide, and A‐heptasaccharide). Their amounts were much less as compared to the amounts present in feces. These results indicate that milk is a possible source for the smallest A‐tetrasaccharide found in the feces of breast‐fed infants, while the larger A‐active oligosaccharides might be the result of an intestinal metabolic modification