Six infants have become beneficiaries of Shanghai's first breast milk bank launched recently for premature or sick babies.

Breast milk provides the best nutrition for infants and helps fight disease, according to doctors.

More than 100 women have donated spare breast milk to the bank at Children's Hospital of Shanghai, according to Wang Yizhong, a gastroenterologist at the hospital.

Parents of premature babies, or babies with very low birth weight or with disorder of the digestive tract - as well as those that undergo surgery or show intolerance to infant formula - can apply through their doctors if the mother fails to produce sufficient milk.

Gong Xiaohui, deputy director of the hospital's neonatal department, said breast milk is irreplaceable as it contains elements that boost immunity in infants.

"However, only about 20 percent of women who have a premature birth are ready for lactation," Gong said.

The European Society for Paediatric Gastroenterology Hepatology and Nutrition said in 2013 that donated human milk is the best substitute for premature babies whose mothers cannot breast-feed.

The society said it has been proved that human milk effectively promotes intestinal maturation and development of those infants and significantly reduces the occurrence of digestive diseases, as well as cardiovascular diseases later in life.

Donors must pass a health examination, including a blood screening, to ensure they are disease-free.

Breast milk will be stored in the freezers for a maximum of six months and will be discarded if not used.

There are more than 10 such banks in the country, but most are experiencing financial difficulties. The milk is provided free, but a large amount of money is poured into operations, maintenance and testing.

"We're calling on charity groups to help us with funding after the initial capital provided by the government runs out after two years," said Zhang Ting, director of gastroenterology at the Shanghai hospital.