I get mixed results with Sacch. Boul. in the clinic, I'd say 50/50. For some folks its spectacular, for others, zilch. That's why a mixed product makes more sense to me, and why fermented & cultured foods as well as various mixed probiotics seems a more reasonable approach.
I agree about the aged cheeses too, but those moldy cheeses in those foil packages can really send some folks to hell and back.
I also agree about going slow when you at first introduce foods like sauerkraut, I started real slow and can now eat plates of the stuff, I just love it.