its definitely trial and error. unfortunately i have never got any results from probiotic, good or bad, its like i am taking nothing, lol.
here is what i have tried:
vsl3 DS (for 9 months!)
benebiotics
jarrows sacch boulardi
sustenex
and a few more that others here take..
i also made and ate homemade kefir DAILY for 3 months. Kefir is a natural source of probiotics, with TRILLIONS of strains of good bacteria, and NOTHING, NO change in my UC
There are others here that have had alot of luck with probiotics so i think it is worth a try, since we are all so individual. There is one more prob called Mutaflor i think that i would still like to try but it is really expesive and at this point i put probiotics on my back burner... for what its worth, diet mod never helped my uc either. only thing working is a combo of lialda, rowasa and imuran. good luck to you...