It's definitely a good thing to go and get checked out to see if any ailments can be addressed medically or just by diet. It's also definitely a good thing to be in a good mood or a good mental space when having a stutter, since it tends to take its toll, yet we have more surplurs for handling that sort of thing, if we're in that good place. But there's definitely no connection in general between stuttering and gluten. Perhaps you've found a personal synergy in terms of the above, but other than that, it's not a thing. Definitely keep up the good spirit, though! We sometimes help ourselves even when we didn't know we could. :)