It might but you can easily replentish them with pro biotics.
Iv'e heard that Colloidal Silver doesn't kill the good bacteria because good bacteria lives off of oxygen and isn't effected by the Colloidal Silver . Iv'e also heard that Colloidal Silver is absorbed by the body before it gets to the good bacteria.
You should notice that on the internet you will find plenty of people that will oppose just about anything. Especially if they have a vested interest.
I have heard of no individual that has been seriously harmed by using colloiodal silver. If it hurts you I will eat my hat.