Human breast milk stem cells: a new challenge for perinatologists

The lactating mammary gland contains a stem cells population with multilineage potentialities. Recently it was also shown that breast milk contains a heterogeneous population of stem cells that have the potential to differentiate in vitro, under the control of specific differentiation conditions, into mammary epithelial as well as into adipogenic, chondrogenic and osteogenic cell lineages. While the different types of cells present in the milk is known, what is less understood is the proportion of different milk cell types, their significance for the mother and the infant and factors influencing them. In this manuscript we summarize some of the latest knowledge from in vivo and in vitro investigations on breast milk stem cells, we discuss their potential functions and applications and we present some of our preliminary data obtained in fresh human breast milk cells.