Coeliac disease By January 2004, extremely low-gluten Church-approved hosts had become available in the United States, Italy and Australia. As of July 2017, the Vatican still outlawed the use of gluten-free bread for Holy Communion. The Jewish festival of Pesach (Passover) may present problems with its obligation to eat matzo, which is unleavened bread made in a strictly controlled manner from wheat, barley, spelt, oats, or rye. This rules out many other grains that are normally used as substitutes for people with gluten sensitivity, especially for Ashkenazi Jews, who also avoid rice. Many kosher-for-Passover products avoid grains altogether and are therefore gluten-free.
Matzo for the Eucharist are flat, unleavened bread. The main reason for the use of this bread is the belief, that because the last supper was described in the Synoptic Gospels as a passover meal, the unleavened matzo bread was used by Jesus when he held it up and said "this is my body". All Byzantine Rite churches use leavened bread for the Eucharist as this symbolizes the risen Christ. Some Oriental Orthodox and Eastern Catholic Christians use leavened bread, as in the east there is the tradition, based upon the gospel of John, that leavened bread was on the table