Gluten is a protein found in wheat that can cause allergic reactions and sensitivity in many individuals, leading to disorders such as gluten sensitivity and celiac disease. The latter is an autoimmune condition where the body attacks gluten proteins and digestive enzymes, resulting in severe health issues. To prevent these diseases, it's advisable to follow a gluten-free diet, which includes grains like corn and quinoa, and to monitor for adverse effects after a period of avoidance.