S. boulardii is the generic name,
and a brand name for it is Florastor. It is *yeast-based* and so is not affected by when you take antibiotics.
(My LLMD has his patients take Florastor for that very reason, but I had problems with it -- I'm apparently genetically yeast-sensitive, and ended up with a really bad systemic fungal infection that took some effort to get rid of. My LLMD said he had never seen that happen before, and I believe him ... but it can happen, just fyi, fwiw.