Assay of ghrelin concentration in infant formulas and breast milk

AIM: To test if total ghrelin is present in infant formulas. METHODS: Using a radioimmunoassay, we measured total ghrelin concentrations in 19 samples of commercial infant formulas and in 20 samples of human milk. We also determined ghrelin concentration in the serum of infants and lactating mothers. RESULTS: Ghrelin concentrations were significantly higher in artificial milk (2007.1 ± 1725.36 pg/mL) than in human milk (828.17 ± 323.32 pg/mL) (P = 0.005). The mean ghrelin concentration in infant serum (n = 56) was 1115.86 ± 42.89 pg/mL, and was significantly higher (P = 0.023) in formula-fed infants (1247.93 ± 328.07 pg/mL) than in breast-fed infants (1045.7 ± 263.38 pg/mL). The mean serum ghrelin concentration (mean ± SD) in lactating mothers (n = 20) was 1319.18 ± 140.18 pg/mL. CONCLUSION: This study provides evidence that total ghrelin is present in infant formulas. This findingraises diverse questions regarding the uptake, absorption and metabolic effects of this hormone.