Yes it does. My nephew is also taking Dexolac stage 1. he turned 4 months last Monday. It helps in building immunity and contributes in growth too

Personally haven't tried this one. I used to give my baby Aptamil gold formula milk. It conatains prebiotics and HMO. It's the closest to breast milk and helps in overall development of the baby.

No idea I am giving aptmil formula milk with HMO AND prebiotics which is good for digestion and helps to keep the gut healthy and grows good bacteria and improve the immune system.