What has gluten in it?
Gluten
wheat, barley, rye, oats and related species and hybrids
Gluten (from Latin gluten, "glue") is a composite of storage proteins termed prolamins and glutelins[1] that is stored together with starch in the endosperm (which nourishes the embryonic plant during germination) of various cereal (grass) grains. It is found in wheat, barley, rye, oats and related species and hybrids (such as spelt, khorasan, emmer, einkorn, triticale, etc.),[2] as well as products derived from these grains (such as breads and malts). Glutens, and most especially the Triticeae glutens, are appreciated for their viscoelastic properties,[3][4] which give dough its elasticity, helping it rise and keep its shape and often leaving the final product with a chewy texture.