title: Intestinal dysbiosis and reduced immunoglobulin-coated bacteria associated with coeliac disease in children.
abstract: BACKGROUND
  Coeliac disease is a chronic intestinal inflammatory disorder due to an aberrant immune response to dietary gluten proteins in genetically predisposed individuals. Mucosal immune response through IgA secretion constitutes a first line of defence responsible for neutralizing noxious antigens and pathogens. The aim of this study was the characterization of the relationships between immunoglobulin-coated bacteria and bacterial composition of faeces of coeliac disease (CD) patients, untreated and treated with a gluten-free diet (GFD) and healthy controls.
  
  
  RESULTS
  IgA-coated faecal bacterial levels were significantly lower in both untreated and treated CD patients than in healthy controls. IgG and IgM-coated bacterial levels were also significantly lower in treated CD patients than in untreated CD patients and controls. Gram-positive to Gram-negative bacteria ratio was significantly reduced in both CD patients compared to controls. Bifidobacterium, Clostridium histolyticum, C. lituseburense and Faecalibacterium prausnitzii group proportions were less abundant (P < 0.050) in untreated CD patients than in healthy controls. Bacteroides-Prevotella group proportions were more abundant (P < 0.050) in untreated CD patients than in controls. Levels of IgA coating the Bacteroides-Prevotella group were significantly reduced (P < 0.050) in both CD patients in comparison with healthy controls.
  
  
  CONCLUSIONS
  In CD patients, reduced IgA-coated bacteria is associated with intestinal dysbiosis, which altogether provide new insights into the possible relationships between the gut microbiota and the host defences in this disorder.
authors.affiliation: Ecofisiología Microbiana y Nutrición, Instituto de Agroquímica y Tecnología de Alimentos (CSIC), Apartado 73, 46100 Burjassot, Valencia, Spain.
authors.forename: Giada
authors.initials: G
authors.lastname: De Palma
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Nadal
authors.forename: Marcela
authors.initials: M
authors.lastname: Medina
authors.forename: Ester
authors.initials: E
authors.lastname: Donat
authors.forename: Carmen
authors.initials: C
authors.lastname: Ribes-Koninckx
authors.forename: Miguel
authors.initials: M
authors.lastname: Calabuig
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Sanz
mesh_terms: D000907:Antibodies, Bacterial / Q000276:immunology*; D001419:Bacteria / Q000276:immunology / Q000378:metabolism*; D016022:Case-Control Studies; D002446:Celiac Disease / Q000276:immunology / Q000382:microbiology*; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000382:microbiology; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry / Q000276:immunology*; D007223:Infant; D054892:Metagenome; D018709:Statistics, Nonparametric
chemical_list: D000907:Antibodies, Bacterial; D007136:Immunoglobulins