Milk

Lactose or milk sugar is a disaccharide and is the main carbohydrate in mammalian milk. Breast milk has the highest lactose content of all mammalian milks, averaging 7 g/100 ml. 

Lactose serves as a quick source of energy for the brain, red blood cells and skeletal muscles. It plays an important role as a dietary fibre.

With their metabolism not yet fully developed, infants are unable to digest the entire amount of lactose. The rest is used as dietary fibre and fermented by the intestinal bacteria. This promotes the growth of healthy intestinal bacteria (bifidobacteria and lactobacilli).