Does cinnamon's anti bacterial property cancel yogurt's pro-biotic properties?

Answer 1

If you are asking if you can eat them together - yes.
Will they negate each others' effect? maybe - hasn't really been studied.
Should you mix them together for a douche - no.
Pro-biotics promote the growth of healthy bacteria [ normal flora ] that normally live in your gut, vagina, on skin, etc.

Answer 2

Interesting question.

I am not sure what you are focusing on. If you're asking will cinnamon kill off the live bacteria in yogurt, no...but that seems sensible due to the huge difference in the weight of each usually used in any tasty yogurt concoction.