I would use kefir as part of my breakfast? On museli for instance.
But you say not near bitters etc.
It is better to take the kefir first thing in the morning as soon as you wake up. Then go about your day for a little while before eating breakfast. This works best since eating will increase stomach acidity and slow down emptying of the stomach. You want to get the bacteria out of the stomach and in to the stomach as soon as possible. So you should give the kefir 30 minutes or more before eating. Also, some foods may contain antiseptic spices. Muesli is fine, but if people eat other foods like a spicy omelet they may kill the flora.