Relationships Among Microbial Communities, Maternal Cells, Oligosaccharides, and Macronutrients in Human Milk.

Background:Human milk provides all essential nutrients necessary for early life and is rich in nonnutrients, maternally derived (host) cells, and bacteria, but almost nothing is known about the interplay among these components.Research aim:The primary objective of this research was to characterize relationships among macronutrients, maternal cells, and bacteria in milk.Methods:Milk samples were collected from 16 women and analyzed for protein, lipid, fatty acid, lactose, and human milk oligosaccharide concentrations. Concentrations of maternal cells were determined using microscopy, and somatic cell counts were enumerated. Microbial ecologies were characterized using culture-independent methods.Results:Absolute and relative concentrations of maternal cells were mostly consistent within each woman as were relative abundances of bacterial genera, and there were many apparent relationships between these factors. For instance, relative abundance of Serratia was negatively associated with somatic cell counts (...