If xanthan gum is listed on the ingredients, how do you know it was grown on a base that wasn’t wheat?

Dr. Amy Nett: Yeah, xanthan gum is generally made through a fermentation process that often uses glucose, but you can sometimes use lactose as well. And I’m not sure that xanthan gum, even if it was grown on a wheat base would actually necessarily contain the antigens from gluten, so I’m not too sure about that one, but I generally don’t recommend against xanthan gum and have people specifically avoid that just because of a gluten allergy. We’ll have to look into that one a little bit more.