Just wondering?

Maybe I'm not totally understanding what you are trying to prove but wouldn't there be a lot of things that would inhibit the action of the yogurt medium?  What would happen if you put ACV or lemon juice in it?  What about Coca-cola, coffee, tea?  What about beer or alcohol?  Even green powders?

I don't think that would prove that these things would kill the good bacteria in your intestines.