Roll the dice symptoms and conditions

I have had sinusitis(es) for 12 years, and been prescribed most of the different
antibiotics. Sometimes, they do a culture and sensitivity, but usually not.
They just roll the dice, and pick their favorite one.
I have had confirmed sinusitis that responded only to Levaquin (or Tequin), and some
that didn't, but did get cured under Augmentin (amoxicillin +), or one of the others:
Biaxin, penicillin, Cipro, you name it.
The side effect I noticed most with Levaquin, though, is the stomach upset.
When I remember to eat yogurt everyday, though, I am fine.
Why don't Americans know about yogurt?
In Europe, I am told, the pharmacist "prescribes" some pills that have the same
cultures as yogurt, when you get antibiotics.