Intestinal DNA methylome of preterm pigs

DNA methylation plays important roles in normal development as well as sensing environmental exposures, thereby regulating transcription that is associated with cellular functions. Shortened gestational age and unexpected exposure to milk and microbes at the wrong time may affect intestinal development and health via DNA methylation. The present studies aimed to characterize the intestinal DNA methylomes of preterm neonates at birth and during postnatal development, in order to understand the cellular basis of the immature intestine and its interaction with early nutrition. In the present studies, preterm pigs were used as a model for preterm infants and the intestinal DNA methylome was analyzed by reduced representation bisulfite sequencing. In study 1, caesarean-delivered preterm or term pigs were euthanized shortly after birth or fed either total parenteral nutrition (TPN) or minimal enteral nutrition (MEN) using bovine colostrum (COL) for five days, followed by full enteral feeding with bovine milk until weeaing (26d). Intestinal DNA methylomes between preterm and term pigs at birth, on 5d and 26d were compared. In study 2, preterm pigs were fed MEN using either COL or infant formula (FOR) for five days, and intestinal DNA methylomes between 5d-old and newborn preterm pigs were compared.