Human: I've heard that a lot of people are going gluten-free. What is gluten and why are people avoiding it? Assistant: 
Gluten is a protein found in wheat, rye, and barley. It is responsible for the elasticity of dough. People who are avoiding gluten are doing so because they have celiac disease or gluten sensitivity. Celiac disease is an autoimmune disorder where the body’s immune system attacks the small intestine. Symptoms include abdominal pain, bloating, diarrhea, constipation, weight loss, fatigue, and iron deficiency.