According to the Catholic church rules, the recipe for the bread used during communion should be made purely of wheat–no substitutions. Surprisingly, people can buy gluten-free communion wafers online, but this really defeats that purpose of having to go to church to receive the holy communion. The letter states that the bread and wafers “must be unleavened, purely of wheat, and recently made so that there is no danger of decomposition.” People that “are completely gluten-free are an invalid matter for the celebration of the Eucharist.” Yet, low-gluten wafers and bread may be used. 
“Christ did not institute the Eucharist as rice and sake, or sweet potatoes and stout,” said Chad Pecknold, a theology professor at Catholic University. Some theologians argue that the bread and wine are symbolic and that it’s not a big deal if they don’t eat the bread. “It may seem a small thing to people,” Pecknold says to the Washington Post. “But the Catholic Church has spent 2,000 years working out how to be faithful to Christ even in the smallest things. To be vitally and vigorously faithful … is something which is simply integral to what it means to be Catholic.”
