This comes from a GI newsletter that I recieve.
Gluten-free diet reduces beneficial bacteria in gutA small study of 10 people who followed a gluten-free diet found they had fewer beneficial gut bacteria, such as Bifidobacterium and Lactobacillus, and more potentially harmful bacteria, such as Enterobacteriaceae and Escherichia coli. Researchers said people on the diet also had fewer immune health markers. FoodNavigator
Another part of the newsletter mentioned not getting on a gluten-free diet unless you are diagnosed with Celiac's. I wouldn't go that far, since you might have it and it not show up on a test, or you might have something else that also causes you to have problems with gluten, HOWEVER, if you don't notice an improvement of symptoms while on a gluten-free diet, you should not stay on it "just in case," because you might make your sympoms worse. And if you are on one, a daily dose of probiotics (pills or yogurt) should be in order to help keep the good bacteria thriving in your gut. It certainly won't hurt anything.