Corn syrup contains trace amounts of gluten. Corn and corn by-products contain zein, a different form of gluten than that in traditional grains, such as wheat, barley and rye. However, when consumed, this form of gluten has a similar effect in the body as grain gluten.
The gluten found in corn has a similar amino acid sequence to that of wheat gluten. People who have celiac disease or a gluten sensitivity generally tolerate this form of gluten well, although it can cause a reaction in some people. Other corn products that contain trace amounts of gluten include corn oil, corn alcohol and corn starch.