I'd been using some kibble with my dogs along with raw until a few weeks ago, when I decided to eliminate the kibble. Along with that bag in the pantry, I eliminated Ziggy's gas problem completely.
Many, many dogs have gas issues and are never given anything except the dried up stuff their owners have been told is "the only healthy diet" for them. Go to your own doctor some time and tell her you eat the excact same dried crackers every day with nothing fresh ever, and see how healthy your doctor thinks that is.
"Dog food" is made from the same ingredients as "people food" except almost always lower quality versions and with more fillers. It's made with a lot of different ingredients because the big selling point is that it covers all the bases nutritionally. This allows dog food companies to convince people that the "healthy" thing to do is to feed the dog the same dried up crackers every day. It also sets up a strong possibility that one or more ingredients will be things that the dog can't digest or that the dog is sensitive or allergic to.
Probiotics may help if there's an imbalance or deficiency and if that solves the problem that's awesome. Beano may help for some dogs, not for others. But if it only mitigates the problem, that means the dog still isn't digesting the food well and that is not a healthy situation in the long term. The more we learn about immunity, the more we realize how important a healthy gut is. Constantly irritating the gut with food that can't be properly digested isn't healthy.