D.L.
C diff is horrible!!! I had it and so has my MIL, not fun, hope you don't have it. I very much agree that you need to get a high quality yogurt (Chobani greek yogurt is good, but any that has active live cultures will help. Try to stay away from a lot of the added sugars and junk in it), You may need to add a probiotic supplement, but make sure you get a really good one, (not one from walmart ), you need to research this part.
I don't have any idea about whether it would be harmful to a baby, just know how miserable it is---soooo sorry.