Continue breast feeding the baby ans include food which are rich in prebiotics as it keeps the gut healthy. If you are breastfeeding the baby there it is sufficient And if you are formula feeding then opt for a formula which contains prebiotics and HMOs

By giving the right formula milk and I would suggest you aptmil gold formula milk

As I had issues and could not feed so I had to give formula milk my peadtric suggested aptamil gold formula milk which contains HMO and prebiotics in it for improving immunity and over all development of baby

What's the age of your baby