Actually, in the Catholic faith, it isn't symbolic. That's why I found this article so interesting. Due to the transubstantiation of the bread into the body of Christ during Eucharist, one might think that the host becomes gluten-free. I was musing that the concern of celiacs could be considered a lack of faith.
I sometimes go to church with my RPS and her grandmother. I haven't taken communion since I was a teenager and now refuse to as an adult, for lots of reasons including the 'willingly partake of human flesh' bit. When she offers up the 'You are always welcome to take communion, I know you were confirmed as a teen' I'm always fighting back a lecture on the pagan origins of ritualistic cannibalism in general and 'god eating' in specific. The struggles of the former anthropology major and lifelong apostate.
Does that cause a problem for vegetarians or vegans?