HP and major depressive disorder: Loss of gut barrier function (evaluated by serum IgG/IgA/IgM responses to occludin and zonulin and IgA responses to actomyosin) with subsequent increased serum levels of microbiota-derived molecules (assayed by testing serum lipopolysaccharides and bacterial toxins, including cytolethal distending toxin) and activation of the immune system (increased cytokines production) leading to neuroinflammation has been described in many neuroimmune disorders, including chronic fatigue syndrome, autism spectrum disorder (ASD), major depressive disorders (MDDs), and schizophrenia32.