From the website of the USCCB:
Can a priest or bishop change this teaching and consecrate a host made of rice??
No. It is impossible to consecrate a host made of something other than wheat and water. No priest or bishop can change this longstanding teaching of the Catholic Church. A little over a year ago, Cardinal Joseph Ratzinger, Prefect of the Congregation for the Doctrine of the Faith, once again took up this question on behalf of the Holy Father when he wrote: “Hosts that are completely gluten-free are invalid matter for the celebration of the Eucharist.”2 Cardinal Joseph Ratzinger, circular letter to the Presidents of Conferences of Bishops, July 24, 2003 (Prot. 89/78-174/98) in BCL Newsletter, November 2003 (Vol. XXXIX), p. 45.
The Jesuits raised this question for reasons of inculturation when they entered China (or was it Japan?) in the 1600s, they got the same answer then.
Interesting.
In Indonesia, where the staple of the diet is sweet potatoes not wheat, when the Protestant missionaries were discussing what to do about communion for the Christian nationals, some of them decided that it would give communion more meaning to portray Jesus as the sweet potato of life, something they could understand and really identify with, as opposed to bringing in wheat whatever and portraying Jesus as the *foreigners food of life*.
An interesting concept and one that works if one recognizes the symbolism of communion.
I like thinking about "true food" ("Food indeed").