The role and molecular mechanisms of amino acids in enhancing mammary gland milk synthesis – a comprehensive review

Breast milk, recognized as the most natural and optimal source of nutrition for infants, is indispensable for their growth and development. Accumulating evidence underscores the pivotal role of amino acids (AAs) as essential precursors in milk synthesis, supporting mammary gland functionality and milk production through the regulation of cellular metabolism and growth. This review comprehensively examines the influence of AAs on mammary epithelial cells (MECs) proliferation and the structural integrity of the blood-milk barrier (BMB). Specifically, we highlight the mechanisms by which AAs facilitate the synthesis of milk proteins and lipids, as well as their role in modulating prolactin (PRL) release within the neuroendocrine system. Furthermore, we provide an in-depth analysis of amino acid metabolism in mammary lactation, offering novel insights into how AAs enhance mammary gland lactation capacity. These findings not only advance our understanding of AAs functions in lactation but also present innovative strategies for optimizing breast milk synthesis.