[Advances in the knowledge about human milk proteins]

Area of Science:

• Human Physiology
• Biochemistry
• Developmental Biology

Background:

• Maternal milk is an evolutionarily optimized fluid essential for newborn and infant growth, adaptation, and survival.
• Human milk contains over 1600 identified proteins, originating from both mammary tissue and other organs.
• Milk enzymes and peptides play vital roles in modulating protein activity and providing bioactive functions.

Purpose of the Study:

• To review the key physiological and compositional aspects of maternal milk.
• To highlight the functional significance of milk proteins and enzymes for infant development.
• To discuss the regulatory mechanisms within maternal milk.

Main Methods:

• Literature review of recent studies on human milk composition and physiology.
• Analysis of protein and enzyme content in maternal milk.
• Examination of the functional roles of milk components in infant gastrointestinal tract.

Main Results:

• Human milk contains a vast array of proteins (1606 identified) with diverse origins and functions.
• Milk enzymes modify proteins, releasing bioactive peptides with antimicrobial, antihypertensive, and stimulatory effects.
• Specific milk enzymes, like enterokinase and bile salt-activated lipase, support infant digestion and nutrient absorption, compensating for immature neonatal systems.

Conclusions:

• Maternal milk possesses a complex regulatory system involving enzymes, inhibitory, and stimulatory peptides.
• Milk enzymes are active in the infant's gastrointestinal tract, aiding digestion and nutrient availability, particularly for premature infants.
• These enzymatic activities may enhance amino acid and peptide absorption and contribute to the development of immune tolerance in infants.