In addition, IgA has a major role in the immunosuppressive mechanisms in the intestine that inhibit proinflammatory responses to oral antigens, which is part of the oral tolerance mechanisms in the intestine [158] . This suppression of the proinflammatory mechanisms is counterbalanced by systemic immune factors, including systemic IgG, which may result in inflammation and tissue damage once an antigen crosses epithelia barrier to the lamina propria [158] .