title: Role of intestinal microbiota in the development of multiple sclerosis.
abstract: BACKGROUND
  Multiple sclerosis (MS) is a demyelinating disease that affects young adults; in that age group, it represents the second leading cause of disability in our setting. Its precise aetiology has not been elucidated, but it is widely accepted to occur in genetically predisposed patients who are exposed to certain environmental factors. The discovery of the regulatory role played by intestinal microbiota in various autoimmune diseases has opened a new line of research in this field, which is discussed in this review.
  
  
  METHODS
  We reviewed published studies on the role of the microbiota in the development of both MS and its animal model, experimental autoimmune encephalomyelitis (EAE). In mice, it has been shown that intestinal microorganisms regulate the polarisation of T helper cells from Th1-Th17 up to Th2, the function of regulatory T cells, and the activity of B cells; they participate in the pathogenesis of EAE and contribute to its prevention and treatment. In contrast, evidence in humans is still scarce and mainly based on case-control studies that point to the presence of differences in certain bacterial communities.
  
  
  CONCLUSIONS
  Multiple evidence points to the role of microbiota in EAE. Extrapolation of these results to MS is still in the early stages of research, and studies are needed to define which bacterial populations are associated with MS, the role they play in pathogenesis, and the therapeutic possibilities this knowledge offers us.
authors.affiliation: Servicio de Neurología, Hospital San Pedro, Logroño, La Rioja, España. Electronic address: fcastilloa@riojasalud.es.
authors.forename: F
authors.initials: F
authors.lastname: Castillo-Álvarez
authors.affiliation: Servicio de Neurología, Hospital San Pedro, Logroño, La Rioja, España.
authors.forename: M E
authors.initials: ME
authors.lastname: Marzo-Sola
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology* / Q000382:microbiology; D000069196:Gastrointestinal Microbiome / Q000276:immunology*; D006801:Humans; D051379:Mice; D009103:Multiple Sclerosis / Q000276:immunology / Q000382:microbiology*
keywords: Autoimmunity; Autoinmunidad; Encefalomielitis autoinmune experimental; Esclerosis múltiple; Experimental autoimmune encephalomyelitis; Immunology; Inmunología; Microbioma; Microbiome; Microbiota; Multiple sclerosis