Bovine Colostrum as a Human Milk Fortifier for Preterm Infants

Very preterm infants (\<32 weeks gestation) show the immaturity of organs and have high nutrient requirements for growth and development. In the first weeks, they have difficulties tolerating enteral nutrition (EN) and are often given supplemental parenteral nutrition (PN). A fast transition to full EN is important to improve gut maturation and reduce the high risk of late-onset sepsis (LOS), related to their immature immunity in gut and blood. Conversely, too fast increase of EN predisposes to feeding intolerance and necrotizing enterocolitis (NEC). Further, human milk feeding is not sufficient to support nutrient requirements for growth of very preterm infants. Thus, it remains a difficult task to optimize EN transition, achieve adequate nutrient intake and growth, and minimize NEC and LOS in the postnatal period of very preterm infants. Mother´s own milk (MM) is considered the best source of EN for very preterm infants and pasteurized human donor milk (DM) is the second choice if MM is absent or not sufficient. The recommended protein intake is 4-4.5 g/kg/d for very low birth infants when the target is a postnatal growth similar to intrauterine growth rates. This amount of protein cannot be met by feeding only MM or DM. Thus, it is common practice to enrich human milk with human milk fortifiers (HMFs, based on ingredients used in infant formulas) to increase growth, bone mineralization and neurodevelopment, starting from 7-14 d after birth and 80-160 ml/kg feeding volume per day. Bovine colostrum (BC) is the first milk from cows after parturition and is rich in protein (80-150 g/L) and bioactive components. These components may improve gut maturation, NEC protection, and nutrient assimilation, even across species. Studies in preterm pigs show that feeding BC alone, or DM fortified with BC, improves growth, gut maturation, and NEC resistance during the first 1-2 weeks, relative to DM, or DM fortified with conventional HMFs. On this background, the investigators hy