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.
Bread dietary fiber and antioxidants such as pronyl-lysine, which is being researched for its potential colorectal cancer inhibitory properties. Doughs are usually baked, but in some cuisines breads are steamed (e.g., mantou), fried (e.g., puri), or baked on an unoiled frying pan (e.g., tortillas). It may be leavened or unleavened (e.g. matzo). Salt, fat and leavening agents such as yeast and baking soda are common ingredients, though bread may contain other ingredients, such as milk, egg, sugar, spice, fruit such as raisins, vegetables such as onion, nuts such as walnut or seeds such as poppy. Methods of processing dough into bread