Gut floura are a bacteria, Colloidal Silver , also used medically as Silvarin, prevents bacterial infection... The effects of Colloidal Silver on it floura are simple too extrapolate, too much kills them, anything over 2 micrograms per milliliter for the linked type.
I would imagine nobody has studied the effects of a firearm on a stack of 1965 rookie baseball cards, specifically, but I can picture them and extrapolate from similar results!
The main question, what is it's concentration in the gut? I think research in the mic or minimum inhibitory concentration should give the rest!