I take a probiotic called Floragen3. It's hard to find - my GI special orders it at a few local mom-and-pop pharmacies. It's expensive, too. But it's what he "strongly recommends." I don't know how it compares to the other biggies, though. I know a lot of people online and IRL who like just plain old acidopholus for maintenance, even on abx.
Good luck!