Gluten appears to be bad news for psychosis

Our intestines and our brain are connected directly via the vagus nerve and research has shown that communication goes in both directions, between these organs. The gut can signal to the brain via chemical messengers such as immune mediators & of course, many neurotransmitters are made in the intestines. 

In this case report, researchers were able to pin-point the person's psychotic symptoms as being brought-on by consumption of gluten. The symptoms improved when gluten was removed from the diet and recurred when gluten was introduced again. 

Other research has shown some markers of gluten sensitivity to be elevated in people with a diagnosis of schizophrenia. 

As mentioned in the research articles, gluten can provke a response from the immune system. We have resident immune cells within the brain called microglia, and when these become activated, inflammation in the brain can result.