Like all have said, I think it is an individual call for each of us. The other consideration is that not all probiotics are the same... some are easier on the tum than others (if Lactob. is too strong, some people work up to it with L. Infant., etc). Also, some brands are mainly lactob. when perhaps your Bifid. is what is low, and so on.
Personally, I use varied brands to mix it up - but I don't take more than what "normal" people would so that I don't totally whack myself. Even though I'm not practicing it, I do agree with Imagardener and JB's comments about
introducing new things carefully.
Oh, while on topic, I do take occasional Sach. Boulardi (which is sold as a probiotic, though apparently it is really a yeast?) because it is one of the only ones which function to prevent C. Diff from taking hold on your intestinal walls. Muy importante for me as C-Diff bodyslammed me and tried to keep me down for the count.
So, without a degree in this stuff (counting on you, Malkavian!!), it is very confusing. Research as much as you can, and check in carefully with your reactions. I dread keeping a journal (some kind of mental block), but it really can be helpful in this area.
diagnosed with UC in Feb 2007
taking 12 Asacol/day since then
take Rowasa enema as needed
Mega-dosing on iron due to anemia
Have tried dozens of alternate remedies:
glutamine, sunflower/spinach, omega3, Ayurveda, reflexology, herbal prescriptions, blood allergy testing (avoiding dairy and eggwhites), tried no nightshades, tried SCD (not very strict to be honest), tried Guts to Glory program, briefly tried David Klein diet, mega-probiotics, probiotic enemas, slippery elm enemas, etc. etc.
I know that the right combination for what my tender tummy needs is out there!