title: Monitoring of gluten-free diet compliance in celiac patients by assessment of gliadin 33-mer equivalent epitopes in feces.
abstract: BACKGROUND
  Certain immunotoxic peptides from gluten are resistant to gastrointestinal digestion and can interact with celiac-patient factors to trigger an immunologic response. A gluten-free diet (GFD) is the only effective treatment for celiac disease (CD), and its compliance should be monitored to avoid cumulative damage. However, practical methods to monitor diet compliance and to detect the origin of an outbreak of celiac clinical symptoms are not available.
  
  
  OBJECTIVE
  We assessed the capacity to determine the gluten ingestion and monitor GFD compliance in celiac patients by the detection of gluten and gliadin 33-mer equivalent peptidic epitopes (33EPs) in human feces.
  
  
  METHODS
  Fecal samples were obtained from healthy subjects, celiac patients, and subjects with other intestinal pathologies with different diet conditions. Gluten and 33EPs were analyzed by using immunochromatography and competitive ELISA with a highly sensitive antigliadin 33-mer monoclonal antibody.
  
  
  RESULTS
  The resistance of a significant part of 33EPs to gastrointestinal digestion was shown in vitro and in vivo. We were able to detect gluten peptides in feces of healthy individuals after consumption of a normal gluten-containing diet, after consumption of a GFD combined with controlled ingestion of a fixed amount of gluten, and after ingestion of <100 mg gluten/d. These methods also allowed us to detect GFD infringement in CD patients.
  
  
  CONCLUSIONS
  Gluten-derived peptides could be sensitively detected in human feces in positive correlation with the amount of gluten intake. These techniques may serve to show GFD compliance or infringement and be used in clinical research in strategies to eliminate gluten immunotoxic peptides during digestion. This trial was registered at clinicaltrials.gov as NCT01478867.
authors.affiliation: Departamento de Microbiología y Parasitología, Facultad de Farmacia, Universidad de Sevilla, Seville, Spain.
authors.forename: Isabel
authors.initials: I
authors.lastname: Comino
authors.forename: Ana
authors.initials: A
authors.lastname: Real
authors.forename: Santiago
authors.initials: S
authors.lastname: Vivas
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Síglez
authors.forename: Alberto
authors.initials: A
authors.lastname: Caminero
authors.forename: Esther
authors.initials: E
authors.lastname: Nistal
authors.forename: Javier
authors.initials: J
authors.lastname: Casqueiro
authors.forename: Alfonso
authors.initials: A
authors.lastname: Rodríguez-Herrera
authors.forename: Angel
authors.initials: A
authors.lastname: Cebolla
authors.forename: Carolina
authors.initials: C
authors.lastname: Sousa
mesh_terms: D000293:Adolescent; D000328:Adult; D002446:Celiac Disease / Q000178:diet therapy*; D002648:Child; D002675:Child, Preschool; D002846:Chromatography, Affinity / Q000379:methods; D055050:Diet, Gluten-Free; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D005243:Feces / Q000737:chemistry*; D005260:Female; D005903:Gliadin / Q000032:analysis*; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D010349:Patient Compliance; D010665:Phenylpropanolamine / Q000032:analysis; D055815:Young Adult
chemical_list: D000939:Epitopes; D010665:Phenylpropanolamine; D005903:Gliadin