Human milk is a complex biological fluid that provides nutrients and non-nutritive factors for optimal growth and development of infants. The benefits of breastfeeding on infant health are numerous and include optimized growth, neurological development and immune function, and extend throughout adulthood to include reduced risk of obesity and metabolic syndrome. However, ~40% of women do not meet their breastfeeding goals because they either did not produce enough milk, or were concerned about the quality of their milk. A critical gap in knowledge is our lack of understanding regarding the molecular mechanisms that promote or impair lactation. Understanding these mechanisms will allow us to diagnose and treat women suffering from sub-optimal lactation to promote and better support breastfeeding women.

The first 1000 days of an infant’s life is a unique period of opportunity when the foundations of optimum health, growth, and neurodevelopment across the lifespan are established. The intestine continues to develop during the neonatal period and provides two critical functions. Firstly, it acts as a barrier to prevent the passage of harmful intraluminal entities including foreign antigens, microorganisms and their toxins, and second, it is responsible for regulating the absorption of nutrients. Factors such as diet, genetics and environmental exposures have important implications on intestinal development and function during this period, and can affect the risk for inflammatory bowel disease (IBD). A critical gap in knowledge is our lack of understanding regarding how dietary factors, genetics and environmental exposures interact to promote or impair intestinal development, function and host-microbe interactions. These mechanisms are critical for understanding factors that increase risk for IBD and developing novel therapeutics to address this disease.

Research in the Kelleher Lab is broadly aimed understanding the role of diet, genetics and environmental factors on maternal and infant health with a focus on the role of zinc transport in highly specialized secretory cells. We utilize cultured cells and transgenic mouse models, combined with studies in breastfeeding women and infants, that integrate nutrition with genetics, cell biology, and physiology to address the following two fundamental questions:

How does maternal diet, genetics and environmental exposures affect mammary gland function, milk composition and volume?

How does infant diet, genetics, and environmental exposures affect gastrointestinal development, microbiome expansion, and risk for IBD?