Blood nutrient indices in breast and formula fed infants: amino acids metabolic responses.

Human milk is generally considered as nutritionally the best food for infants, infant formula are usually manufactured to be as similar to human milk as possible, it may appear logical to attempt a metabolic response of formula fed infants similar to that of breast fed infants. We conducted a 8 week growth and metabolic study in 90 healthy term infants fed either human milk, whey dominant formula or casein dominant formula, each group consisted of 30 infants. Results revealed no significant differences were observed among the groups with respect to growth and anthropometric measurements. Serum total protein, albumin were not differ among breast-fed and formula fed infants. BUN and many plasma essential, amino acid were significant higher in formula-fed groups. While plasma tryptophan concentration was lower in two formula fed groups, in addition, plasma taurine was lower in casein dominant group at 4 weeks of age. These results suggested a reevaluation of protein quantity and quality in infant formula is needed.