Abstract Body

Among mothers that initiate breastfeeding, at least one in three will not optimally breastfeed during the first days. They will either initiate breastfeeding more than one hour after delivery and/ or will provide supplement feeding. Besides exposing the child to potential pathogens and /or allergens, this worldwide practice will result in colostrum withdrawal for the neonate. Colostrum, the first fluid produced by the mammary gland, is rich in protein, immune and growth factors. It also has the potential to shape the establishing gut microbiota through its abundance of oligosaccharides and antimicrobial factors. While there is evidence pointing to the importance of colostrum for the prevention of early mortality in low and middle-income countries, there is a lack of knowledge on the long-term health impacts of insufficient colostrum intake. To fill this gap, we have developed a unique pre-clinical model where we compare the development of mice breastfed physiologically to mice breastfed by a dam that differed by the time of initiation of breastfeeding.

Colostrum deprivation at birth caused significant growth failure that persisted into adulthood. Colostrum ignited the somatotropic hormone axis to ensure both weight gain and longitudinal growth. We further found that colostrum at birth was required for the postnatal expansion of Innate lymphoid type 2 cells (ILC2) by promoting their survival. Colostrum-driven ILC2 expansion was necessary for successful control of gut helminth infection in infant mice. Preliminary data in humans corroborated this finding. Given the known importance of the gut microbiota in health and disease, we evaluated the role of the microbiota in the mediation of colostrum’s beneficial health effects. While the gut microbiota diversity and composition were altered in mice lacking colostrum at birth, we demonstrated in germ-free mice that the effect of colostrum deprivation was recapitulated in the absence of microbes.

In conclusion, this talk will highlight that colostrum may represent a missing link for healthy development. Our data revealed that colostrum at birth was critical for later prevention of undernutrition and helminth infection, both representing a major burden of disease in children. They also stressed that the diet in early life can profoundly affect development independently of the microbiota. This unexpected finding suggests that microbiota interventions may not necessarily represent the major focus of new strategies to foster healthy development in early life. Evidence-based promotion of colostrum feeding and the design of colostrum-inspired supplements may change the lives of many children.