α-Lactalbumin-rich infant formula fed to healthy term infants in a multicenter study: plasma essential amino acids and gastrointestinal tolerance

Objective: To evaluate the efficacy and safety of an alpha-lactalbumin-enriched formula with a protein profile and total protein concentration closer to human milk (HM) and lower than conventional formulas. Subjects/methods: Two hundred and sixteen healthy, term infants, <= 14 days post-natal age were enrolled and 166 (76.9%) completed the study. Timed post-prandial plasma essential amino-acid levels were determined after 8 weeks of ad libitum study feeding. Study events were assessed every 2 weeks. Results: At 8 weeks, all mean plasma essential amino-acid levels in the experimental formula (EF) group were as high as the standard formula (SF) and HM groups. The incidence of feeding-related gastrointestinal (GI) events varied significantly (P=0.025) across groups: (SF) (31.3%), EF (17.2%) and HM (13.6%), with SF being significantly higher than HM (P=0.015). Study withdrawals due to feeding-related GI events were signifacntly different (P=0.001) across groups: SF (12.5%), EF (4.7%), and HM (0%). The timing of GI events was also significantly different across groups (P=0.010). Conclusion: The study demonstrated that feeding a higher quality, lower protein concentration formula (alpha-lactalbumin-enriched) met all essential amino acid and protein requirements of infants. The GI tolerance profile of infants receiving the EF was similar to HM-fed infants.