Gluten exorphin

Gluten exorphins are a group of opioid peptides formed during the digestion of the gluten protein. These peptides work as external regulators for gastrointestinal movement and hormonal release. The breakdown of gliadin, a polymer of wheat proteins, creates amino acids that stop the gluten epitopes from entering the immune system to activate inflammatory reactions. During this process, gluten does not fully break down, thus increasing the presence of gluten exorphins. Because of this, researchers think this is what might lead to various diseases. 
Research shows the benefits of gluten- and casein-free diets for people with diseases and disorders connected to gluten exorphins. The mechanism behind this is still unknown. There is a possibility that gluten has deleterious effects on the human digestive system. When people are more susceptible to gluten and casein allergies, the weakened intestinal lining allows gluten exorphin to flow.
Categorization.
There are four known gluten exorphins with known structure:
Clinical significance.
Recent research surrounding gluten exorphins has revolved around how the peptides might play a role in various diseases and disorders.
Celiac disease.
In response to gluten, people with celiac disease will release gluten exorphins as part of the allergic immune response. Due to the weakening of intestinal walls caused by celiac disease, some of these gluten exorphins can make their way through the lining of the intestines and are then absorbed into the bloodstream. Once in the bloodstream, gluten exorphins can reach the brain and cause issues with neurological functions, like in the disorders discussed below. 
Autism.
Autism spectrum disorder (ASD) may be associated with the immune response to gluten and a number of clinical trials have been run to determine the effectiveness of a gluten-free and casein-free (GFCF) diet to alleviate the symptoms of ASD. However reviews of the available clinical evidence found little evidence to support the use of CFCF to treat ASD.
Schizophrenia.
Although a rare disorder, schizophrenia can involve debilitating symptoms for those diagnosed with it. It has been found that celiac disease is twice as likely to occur in people with schizophrenia than in the general population, so it is assumed that there is a connection between the two. Given the knowledge of the gut-brain axis, research has looked into the connection between schizophrenia disorder and gluten allergies. One study gathered that when gluten increases the gut’s permeability, an immune response is sent out in the form of gluten exorphins.
Another study hypothesized that a defect in the gastrointestinal tract could cause gluten-associated antigens to enter the bloodstream more easily. Gluten exorphins may be detrimental to mental processing and functionality if they reach the brain, however the available evidence to support this hypothermia is mixed.