title: Relationship of children's salivary microbiota with their caries status: a pyrosequencing study.
abstract: OBJECTIVE
  Different dental caries status could be related with alterations in oral microbiota. Previous studies have collected saliva as a representative medium of the oral ecosystem. The purpose of this study was to assess the composition of oral microbiota and its relation to the presence of dental caries at different degrees of severity.
  
  
  METHODS
  One hundred ten saliva samples from 12-year-old children were taken and divided into six groups defined in strict accordance with their dental caries prevalence according to the International Caries Detection and Assessment System II criteria. These samples were studied by pyrosequencing PCR products of the 16S ribosomal RNA gene.
  
  
  RESULTS
  The results showed statistically significant intergroup differences at the class and genus taxonomic levels. Streptococcus is the most frequent genus in all groups; although it did not show intergroup statistical differences. In patients with cavities, Porphyromonas and Prevotella showed an increasing percentage compared to healthy individuals. Bacterial diversity diminished as the severity of the disease increased, so those patients with more advanced stages of caries presented less bacterial diversity than healthy subjects.
  
  
  CONCLUSIONS
  Although microbial composition tended to be different, the intragroup variation is large, as evidenced by the lack of clear intragroup clustering in principal component analyses. Thus, no clear differences were found, indicating that using bacterial composition as the sole source of biomarkers for dental caries may not be reliable in the unstimulated saliva samples used in the current study.
authors.affiliation: Stomatology Department, University of Valencia, C/Gascó Oliag 1, 46010, Valencia, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gomar-Vercher
authors.forename: R
authors.initials: R
authors.lastname: Cabrera-Rubio
authors.forename: A
authors.initials: A
authors.lastname: Mira
authors.forename: J M
authors.initials: JM
authors.lastname: Montiel-Company
authors.forename: J M
authors.initials: JM
authors.lastname: Almerich-Silla
mesh_terms: D015373:Bacterial Typing Techniques; D002648:Child; D003731:Dental Caries / Q000453:epidemiology / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D064307:Microbiota; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D025341:Principal Component Analysis; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D012463:Saliva / Q000382:microbiology*; D013030:Spain / Q000453:epidemiology
chemical_list: D012336:RNA, Ribosomal, 16S