A ducted, biomimetic nipple replicates breastfeeding mechanics through ontogeny in an infant animal model

Background: Although there are known physiological and developmental benefits for breastfed infants, many infants must be bottle-fed for a variety of reasons. We hypothesize that some of these health disparities are caused by biomechanical differences in milk acquisition between breastfeeding and bottle feeding (suction versus expression) that are caused by fundamental structural differences between breast tissue (which has narrow ducts) and bottle nipples (which are hollow). Methods: To evaluate if a biomimetic, ducted bottle nipple elicits suckling physiology that is more similar to breastfeeding than conventional bottle feeding, we studied suckling in full-term infant pigs, a validated animal model for infant feeding. We raised one group on each nipple type and fed all pigs from both nipple types at the end of infancy. We recorded synchronous videofluoroscopy and intraoral suction and calculated the rate of milk consumption. Results: Infants raised on ducted nipples generated greater intraoral suction throughout most of infancy. In contrast, infants raised on cisternic nipples compressed the nipples more, swallowed larger boluses, and consumed milk at a faster rate. Conclusions: These differences mirror those reported between breastfeeding and bottle feeding, suggesting that a biomimetic nipple elicits mechanics that are similar to breastfeeding and can improve feeding outcomes. Impact: Milk acquisition from ducted, biomimetic bottle nipples mirrored the mechanics of breastfeeding by eliciting greater suction generation, reduced nipple compression, and a slower rate of milk consumption compared to feeding from cisternic nipples. Differences in the physiology and mechanics of milk acquisition between breastfeeding and bottle feeding can be attributed to the structural differences between ducted breast tissue and hollow bottle nipples. The use of ducted bottle nipples has the potential to reduce disparities in physiological and developmental health outcomes between breastfed and bottle-fed infants and improve the ability for caretakers to transition between breast and bottles for feeding.