Can i give regular activia yogurt to my 8 month old?

Probably: Activia is cows milk based, so if your infant is on cows milk formula, he/she will likely tolerate it. Some people would prefer yobaby or other formulations lower in sugar, but the live cultures in activia tend to be better for gas and constipation (from my experience, not proven in research). And he/she is old enough to begin some healthy table foods, soft and not loaded with salt, sugar etc.