We are redoing our son’s room and we prefer something really soft since he is a baby still and I don’t want him falling and hurting himself. We really would like to put plush carpet there but are worried about collecting bacteria and dust. Is there any type of carpet that is considered more hypoallergenic than others?

Synthetic fibers are more mold and mildew resistant than natural. Have you considered cork though? It is not hard like hardwood. It's hypoallergenic, moisture resistant, spills will wipe right up...you might want to think about it!