If you need a little extra protein in the diet, just mix a little spirulina powder to your gutload mix.
You don't want any sort of animal or dairy proteins, this stuff is all veggie.
Don't use it regular though, maybe a pinch every few months.
And do not feed it to your cham directly (like in dusting).
Just a pinch added to a few cups of chopped up gutload veggies is plenty.