Helminth therapy and multiple sclerosis

► The hygiene or microbial deprivation hypothesis is a putative explanation for the increase of autoimmune disease in the developed world. ► The hygiene hypothesis indicates that autoimmunity may be due to evolutionarily abnormal high levels of sanitation. ► Multiple sclerosis (MS) is a disabling utoimmune neurological disease of young adults. ► MS is characterised by abnormal immunoregulation. ► Helminths are able to promote normal immunoregulation. ► Helminth replacement therapy in animal models and human studies are reviewed in this article. ► Preliminary results of helminth therapy for MS are encouraging. ► Further study is necessary to determine the safety and efficacy of helminth therapy in MS and other autoimmune diseases.