What are the two main protein fractions found in human milk?

The two main protein fractions found in human milk are casein and whey. These proteins play essential roles in the nutrition and development of infants.

Casein is the main protein in human milk, representing about 40% of it. It forms micelles, which help to stabilize calcium and other minerals, making them more bioavailable for the growing infant. This is particularly important for bone development.

Whey protein makes up the remaining 60% of the protein content in human milk. Whey proteins are more easily digested compared to casein, providing amino acids in a readily absorbable form for the infant's immediate nutritional needs. Additionally, whey proteins include important immunoglobulins and lactoferrin, which help support the infant's immune system.

The combination of casein and whey in the specific proportions found in human milk provides a well-balanced source of protein that supports both growth and development in infants. This blend is specifically designed to meet the needs of human infants, making breast milk uniquely suited for them.