People are still debating about when's the best time to take probiotics really.

Refer to the manufacturer's instruction to start with.

I personally recommend taking them after a light meal.

Arguments for taking before food:

So that nothing can compete with its absorption.
Stomach acid content is low when you first wake up

Arguments for taking after food:

We want the probiotics to reach the small intestines, which is where most digestive processes take place. But stomach acid can destroy the bacteria in probiotics before they reach there. Food helps to shield the probiotics from stomach acid.

Anyways, just remember that heat can kill the good bacteria, so never have them with hot drink!