Try avoiding gluten for a week. It's really a big problem for a lot of people - more now than ever. It might work for you.
My digestive system improved with a few things. First, lysine... i know that sounds so weird, but it helps for some reason. Also, I drink that Dan-Active stuff which has natural healthy bacteria. The best "pro biotic" you can take is "florastor" (google it - it's really good for digestion) but it's expensive. I also take fish oil which can reduce inflammation, and I feel like it regulates appetitie which could help with benzo belly. For some reason, tapering benzos makes me want endless surgar and carbs - especially at night - cuz they make me tired... so I just bought frozen fruit from whole foods which sort of satisfies that craving but is much healthier. well theres some ideas...good luck.