Here is the English translation of the provided content: "How can we improve a baby's immunity?"

Patient's question:

Age of the baby: 4 weeks old
Immunity: The baby's immunity is very low.
Medical history: The baby has never been breastfed and has been drinking formula milk since birth. Currently, the baby often suffers from colds, diarrhea, and other conditions, requiring long-term intravenous treatment each time.
Previous treatment and effectiveness: No treatment has been administered. The baby's mother is unsure how to improve the baby's immunity.
Help needed: The mother wants to know how to enhance the baby's immunity.

Doctor's answer:

I. Breastfeeding
Before birth, babies can receive immunity through antibodies via the placenta. After birth, the breast milk, rich in antibody components that boost immunity, can protect the baby until they develop their own immune system. Therefore, mothers should strive for scientific breastfeeding to help their babies strengthen their immunity. Do not give up on breastfeeding lightly, as it will have a profound impact on the baby's health.
II. Nutritious Foods
Specific nutrients in food play a key role in supporting the baby's immune system. The choice of food depends on the stage the baby is in: during breastfeeding, breast milk is the best nutritional food; during the weaning stage, breast milk and complementary foods are the best parallel options; after the age of one, solid foods should be the most suitable choice.