Human breast milk stem cells: characteristics, functions, and future applications

• hBSCs have advanced breast milk research over the last decade • hBSCs could regulate lactation, promote infant and child growth and development • hBSCs could promote disease treatment and cellular milk production. • hBSCs can be expanded and cultured as seed cells, differentiated into lactating cells • hBSCs could enhance milk and components, and improve infant formula ingredients. Human breast milk stem cells (hBSCs) represent a distinct category of stem cells sourced from breast milk, with the remarkable capabilities of self-renewal and multi-lineage differentiation. HBSCs hold tremendous potential for cell therapy and for the construction of breast bioreactors for the production of breast milk or its components. Numerous studies suggest that hBSCs could be transferred to an infant’s body during breastfeeding, playing a pivotal role in the development of various organs, tissues, and the nervous system. Currently, hBSCs demonstrate diverse application values across multiple domains. In basic research, they can differentiate into lactating cells or organoids, providing an important in vitro cell model for investigating lactation mechanisms and disease treatments. In the realm of infant and child health, hBSCs may exert a significant influence by regulating the lactation process and promoting the growth and development of infants and children. Moreover, in terms of biotechnological applications, their potential in the production of cell-based dairy products has also attracted much attention. Nevertheless, many of the functional mechanisms of hBSCs remain incompletely understood. This review systematically expounds upon the discovery, biological characteristics, and research progress regarding the functions of hBSCs. Future research should focus on further exploring the action mechanisms of hBSCs to fully exploit their application scenarios in the fields of medicine and biotechnology.