The mucosal immune system is constantly exposed to challenges from the antigenic substances found in food and released from the body's own microbial flora. The body's normal tolerance to friendly antigenic substances can be disrupted by a number of factors, such as disease, injury, shock, trauma, surgery, drugs, blood transfusion, environmental triggers, etc. When this disruption happens, the ingestion of foods containing antigenic substances that have compositions similar to those of the body's autoantigens can result in the production of antibodies that react not only against the food antigens but also the body's own tissues. This response is known as food autoimmune reactivity. Between 7% and 10% of the world's population suffers from some form of autoimmune disease. Each patient's antibodies, both immunoglobulin A (IgA) + immunoglobulin M (IgM) in the saliva and immunoglobulin G (IgG) and IgA in the blood must be examined to give a complete picture of food immune reactivity. A host of health problems and autoimmune disorders have increasingly become associated with some of the most commonly consumed foods in the world, such as wheat and milk. Many of these problems can be traced to molecular mimicry. The peptide sequences of foods such as milk and wheat are similar to those of human molecules, such as myelin oligodendrocyte glycoprotein, human islet cell tissue, and human aquaporin 4 (AQP4). This similarity can result in cross-reactivity that leads to food autoimmunity and even autoimmune disorders, such as multiple sclerosis (MS), celiac disease (CD), and neuromyelitis optica. Further research is needed to determine what other foods have dangerous sequence similarities to human tissues and what methods are available to test for the autoantibodies resulting from these molecular, mimicry-induced misfires of the immune system. The identification and removal of corresponding food triggers can then be used as the basis of therapy.