Gas is a sign of maldigestion. Yes, things like yoghurt (specifically the probiotics contained in the yoghurt) do often help a lot. But it is to some extent masking the problem rather than curing it. Plus, dairy products can often be a problem in themselves, so it's not the sort of thing I'd give daily by choice.
You might consider experimenting a little with food - and forms of food - to see if you can find something a bit less problematic for him. For example, a grain-free kibble may be easier for his system to deal with (grains are not easy for dog's digestive systems to deal with). Or you may find greater success with a homecooked, canned or raw diet that likewise exclude grains or gas-producing vegetables. It isn't really something where there are any guarantees (everyone's digestive system copes slightly differently, and intolerances vary between individuals), so you really need to just experiment and see what works best for him. But that's better in the long run than continuing with digestive problems or just masking the problem with probiotics.
Some are worse tham others. Have you tried adding some yogurt to his meals. That helped mine. I do it a couple of times a week. Good luck 
