The association between gluten related disorders and psychiatric diseases has been firmly demonstrated. Non-celiac gluten sensitivity (NCGS) is a syndrome diagnosed in patients responsive to gluten-free diet after ruling out celiac disease and wheat allergy. The pathogenesis of neuro-psychiatric disorders in NCGS is unclear. An association between gluten and schizophrenia was described for the first time in 1950 by Bender et al. In the 1950's, Dicke noted that gluten-free diet improved mood in celiac patients. In 1970, Goldberg et al., in a study of 80 celiac patients, found that 34% of them showed minor affective disorders. Bipolar disorder patients show an increase of blood anti gliadin deamidated antibodies (IgG). The effect of diet and nutrition on autistic spectrum disorders has been investigated in the last two decades, particularly focusing on the symptoms of hyperactivity and attention. Toxoplasma gondii and other neurotropic pathogens as Influenzavirus and Coronavirus may be associated with mood disorders, probably secondary to an increased intestinal permeability. Abnormalities of host-microbiota interactions or of gut-microbiota composition have been associated with central nervous system disorders, such as autism, anxiety, depression and the integrity of intestinal microbiota may be considered a potential therapeutic goal to treat these conditions.