That might work for her, however, I don't see why your friend would need to give probiotic yoghurt, when there are so many other guinea pig-safe probiotic products that do not contain dairy. Impaction can't be cured, and there are other more reliable methods to help control it. Just to add, if a guinea pig did have TOO much protein, it would no doubt cause death. I'm also not sure if you'll be allowed to mention breeding/showing. :x