Probiotics are a waste of time IMO. And money. Better spent time is focusing on a low ph stomach acid, then the rest will be taken care in the intestines, with prebiotics from the food you eat. Then a good repopulation of bacterias will happen.
Stomach acid is designed to wipe out all bacterias, ph 1-2 make sure of this. A good working one that is.
Probiotics may have an effect if (too)high ph stomach acid, then some of the bacterias, or probiotics; may survive.
(But I did not have much effect of it even then.)