Human milk beyond nutrition role to functional and adaptative physiological functions

ABSTRACT

Human milk contains a large amount of various proteins that contribute to the newborn's quality of life. These proteins, when digested, are transformed into peptides and amino acids that help in better absorption of nutrients from milk, some of them such as; amylase, beta- casein, lactoferrin , among others. They also have several activities, such as; immunomodulators , antihypertensives , antimicrobials, antithrombotics and others ( Lönnerdal , 2003). Human milk can be divided into three phases; colostrum, transitional milk and mature milk, and in these three different phases of milk the composition of proteins, peptides, amino acids, sugars and all other components fluctuate a lot. Many of the proteins are synthesized in the mammary gland, with some exceptions such as serum albumin which comes from the blood circulation . Currently, due to the great diversity and quantity of proteins and peptides in human milk, there are large studies on their properties such as; function and quantification of human milk proteins and peptides. With a view to better nutrition for newborns, better identification and biochemical characterization of these compounds. To this end, several steps will be carried out to isolate and characterize new peptides and proteins from human milk and the activities of the new peptides and proteins found in human milk will also be tested. These activity tests will be carried out in cell culture (cell proliferation or cell inhibition effect), blood pressure in rats (hypotensive or hypertensive effects ) and guinea pig ileum (contractile or relaxing effect). Once a peptide or protein with significant function or activity is isolated, peptidomic or cryptic analysis can then be carried out . New insights obtained with proteomics and metabolomics approaches revealed new components present in human milk including cryptides that could be generated in certain conditions by the newborn microbiome Therefore, by better characterizing human milk and its components, there will be better and greater conditions for understanding the nutrition of newborns and premature babies and a better understanding of the physiological role played by these components in relation to the development and growth of the newborn.