Nutritional factors influencing infections in preterm infants

In contrast with clinical studies in term infants or older children, it is very difficult to investigate possible immunoregulatory effects of a novel infant formula composition in preterm infants. This is mainly because of the multicausal origin of infections in this high-risk population that is usually admitted to the neonatal intensive care unit. Possible effects of nutrition composition on onset and incidence of nosocomial infections in these very small infants have to be compared with infections that may have originated in utero. The development of the gastrointestinal tract may be inhibited after severe intrauterine growth retardation, leading to functional impairment of the gut shortly after birth. This may be related to the onset of necrotizing enterocolitis of the newborn. However, this disease in very small preterm infants is possibly also related to the initiation of oral feeding and/or the amount of feeding. Specific infection risks of neonatal intensive care as a result of invasive techniques such as artificial ventilation or total parenteral nutrition using indwellirg umbilical and/or Silastic lines and so-called "all-in-one'' mixtures may influence the incidence of infections. Widespread use of intravenous antibiotics in the neonatal intensive care unit may create an even larger infection risk. Investigation of possible immunomodulatory effects of factors such as prebiotics and probiotics added to the nutrition of preterm infants should always be considered along with other nutritional factors known to influence the immature immune system