Influence of duration of gestation on fatty acid profiles of human milk

Human milk (HM) provides healthy full-term infants with all their nutritional requirements during the first 6 months of life. Fatty acids (FA) and cholesterol derived from HM have many physiological functions in the neonate, including brain myelination, brain function and visual development. HM samples from mothers delivering prematurely (n = 15) and at term (n = 30) were collected. For pre-term mothers, longitudinal HM samples were collected up to 14 weeks post-partum. Thirty-six individual FA were identified and quantified in human milks by fast GC-FID analysis. HM from pre-term mothers had higher contents of saturated FA and long chain-polyunsaturated FA compared to HM from term mothers. The cholesterol content of full-term HM was significantly higher (p < 0.05) than that of pre-term HM up to 5 weeks post-partum. A decrease in the levels of mono-unsaturated FA, poly-unsaturated FA and cholesterol was observed in longitudinal pre-term HM samples. The current study demonstrates how the FA and cholesterol composition of full-term and pre-term HM varies with gestational age and throughout lactation. Practical applications: The current study demonstrates how the FA and cholesterol composition of full-term and pre-term milks varies with gestational age and throughout lactation. The changes were presumably due to the differences in functional maturity of the mammary gland and/or dietary fat and carbohydrates intakes by Irish mothers. This thorough knowledge of lipid profile of human milk could be useful to design a more humanised infant formula in order to ensure the required FA and cholesterol levels of infants are satisfied during early life, particularly in supporting the growth and development of premature babies. Fatty acid and cholesterol composition were quantified by fast gas-chromatography analysis in pre-term and term human milk samples sourced from a milk bank. Significant differences in the saturated FA, long chain-polyunsaturated FA and cholesterol contents were observed between pre-term and term milk samples. Longitudinal pre-term samples showed a decrease in the levels of mono-unsaturated FA, poly-unsaturated FA and cholesterol HM samples. This study has improved the current knowledge regarding the lipid profile of human milk, and the results could be useful in designing functional infant formula products that ensure the required bioactive FA and cholesterol intakes of infants during early life, particularly for support of the growth and development of premature babies.