Milk is the food that is closest to perfection for human beings. Milk not only contains a wide variety of immune substances,but also contains easily digestible nutrients such as casein,bioactive substances such as insulin-like growth factors,and water accounting for more than 87% of milk mass. Milk can enhance the immune function of the human body,quickly supplement the energy,protein and other nutrients required by the human body,promote infant growth and reduce the "three high" indicators,and provide hydration substrate for the body's physiological activities. In addition,many active substances such as exosomes in milk have a wide range of biomedical applications. In this paper,the immunity,nutrition,activity and hydration of milk were reviewed in order to provide reference for better understanding and use of milk and further development of high-quality active milk and dairy products.

milk  /  immunity  /  nutrition  /  activity  /  hydration