Probiotics are mostly a scam. They don't reach the gut to do any good, rather they are just melted by the stomach acid. The ones that have a protective carrier mechanism cab reach the gut, but having a j pouch means it doesn't stay there long enough to thrive. There's only 1 product that has been proved effective for jpouch and that is VSL 3.
The are other probiotics that *may* benefit. I take symprove because it's liquid form so already active when swallowed and doesn't need to be activated like freeze dried (it's also had clinical studies to prove effectiveness, but not with jpouch), another one people rave about is align... No experience with that one though.
If you not taking one of the big 3, you are probably wasting your money imho.
Fwiw I have never had gas from symprove. Previously I took biokult for like 5 years, with hindsight that was money wasted.