The Roman Catholic Church has outlawed the use of gluten-free bread for Holy Communion.

However the Vatican has decreed that it can still be made from genetically modified organisms, the BBC reported.

The ruling was announced in a letter to bishops by Cardinal Robert Sarah, prefect of the Congregation for Divine Worship and the Sacraments.

He has said the bread can be low-gluten, but the wheat must contain enough protein for it to be made without additives.

"Until recently it was certain religious communities who took care of baking the bread and making the wine for the celebration of the Eucharist," the Cardinal wrote in his letter, which he said was sent at the request of Pope Francis.

"Today, however, these materials are also sold in supermarkets and other stores and even over the internet."

He added: “The bread used in the celebration of the Most Holy Eucharistic Sacrifice must be unleavened, purely of wheat, and recently made so that there is no danger of decomposition.

"It follows therefore that bread made from another substance, even if it is grain, or if it is mixed with another substance different from wheat to such an extent that it would not commonly be considered wheat bread, does not constitute valid matter for confecting the Sacrifice and the Eucharistic Sacrament."