Concentration of transforming growth factor‐beta in an infant formula from five countries and human milk from Mexico and the US

Abstract

Transforming growth factor‐beta (TGF‐beta) is found in human milk and is thought to be a key growth factor for the development of the immune system and oral tolerance in neonates. In this study, the concentration of total TGF‐beta (isoforms beta‐1 and beta‐2) was determined in human milk obtained from mothers in the US and Mexico, and compared to that found in an infant formula (Enfamil LIPIL powder) marketed in 5 countries. Human milk samples (n=260) were collected at specific times over the first 26 weeks of lactation from three cohorts of 20 healthy mothers who delivered term babies. Infant formula powder samples (n=25) representing multiple manufacturing sites were obtained from the US, Mexico, Thailand, China, and Philippines. TGF‐beta isoforms were quantified by a specific ELISA method validated for each type of sample. When pooled across the cohorts and collection times, human milk exhibited a geometric mean of 2,700 pg/ml and a 95% confidence interval of 550 ‐ 13,000 pg/ml. The mean concentration of TGF‐beta in the reconstituted infant formula was 4,900 pg/ml with a range of 2,800 ‐ 9,900 pg/ml. These data demonstrate that TGF‐beta is present in infant formula at a level within the range found in human milk.