"Helps digest gluten and carbs," reads the label of me+my Gluten Assist. Really? Breaking down gluten “Gluten is a really tough plant protein,” notes Daniel Leffler, director of clinical research at the Celiac Center at Beth Israel Deaconess Medical Center in Boston. “A variety of enzymes in the stomach are responsible for chopping up proteins, but they don’t work on gluten.” That allows long fragments of undigested gluten to leave the stomach and enter the small intestine. Most people can tolerate those fragments. But not those with celiac disease. “Their immune system mistakes gluten for a dangerous foreign protein, and attacks it the way it would attack bacteria or a virus,” explains Leffler. “That damages the intestine, and causes abdominal pain and diarrhea and so on.”