Human: I've been hearing about this "gluten-free" diet. What is it all about? Assistant: 
The gluten-free diet is a diet that excludes foods containing gluten, which is a protein found in wheat, rye and barley. People who follow the diet are trying to reduce their exposure to gluten, which can be harmful for those with celiac disease or gluten sensitivity. Gluten-free diets have become popular as people look for ways to improve their health and well-being.