title: Maturation of Oral Microbiota in Children with or without Dental Caries.
abstract: BACKGROUND
  The aim of this longitudinal study was to evaluate the oral microbiota in children from age 3 months to 3 years, and to determine the association of the presence of caries at 3 years of age.
  
  
  RESULTS
  Oral biofilms and saliva were sampled from children at 3 months (n = 207) and 3 years (n = 155) of age, and dental caries was scored at 3 years of age. Oral microbiota was assessed by culturing of total lactobacilli and mutans streptococci, PCR detection of Streptococcus mutans and Streptococcus sobrinus, 454 pyrosequencing and HOMIM (Human Oral Microbe Identification Microarray) microarray detection of more then 300 species/ phylotypes. Species richness and taxa diversity significantly increased from 3 months to 3 years. Three bacterial genera, present in all the 3-month-old infants, persisted at 3 years of age, whereas three other genera had disappeared by this age. A large number of new taxa were also observed in the 3-year-olds. The microbiota at 3 months of age, except for lactobacilli, was unrelated to caries development at a later age. In contrast, several taxa in the oral biofilms of the 3-year-olds were linked with the presence or absence of caries. The main species/phylotypes associated with caries in 3-year-olds belonged to the Actinobaculum, Atopobium, Aggregatibacter, and Streptococcus genera, whereas those influencing the absence of caries belonged to the Actinomyces, Bergeyella, Campylobacter, Granulicatella, Kingella, Leptotrichia, and Streptococcus genera.
  
  
  CONCLUSIONS
  Thus, during the first years of life, species richness and taxa diversity in the mouth increase significantly. Besides the more prevalent colonization of lactobacilli, the composition of the overall microbiota at 3 months of age was unrelated to caries development at a later age. Several taxa within the oral biofilms of the 3-year-olds could be linked to the presence or absence of caries.
authors.affiliation: Department of Odontology/section of Pedodontics, Umeå University, Umeå, Sweden.
authors.forename: Pernilla
authors.initials: P
authors.lastname: Lif Holgerson
authors.affiliation: Department of Odontology/section of Pedodontics, Umeå University, Umeå, Sweden; Department of Odontology/section of Cariology, Umeå University, Umeå, Sweden.
authors.forename: Carina
authors.initials: C
authors.lastname: Öhman
authors.affiliation: Department of Odontology/section of Pedodontics, Umeå University, Umeå, Sweden; Department of Odontology/section of Cariology, Umeå University, Umeå, Sweden.
authors.forename: Agneta
authors.initials: A
authors.lastname: Rönnlund
authors.affiliation: Department of Odontology/section of Cariology, Umeå University, Umeå, Sweden.
authors.forename: Ingegerd
authors.initials: I
authors.lastname: Johansson
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics; D018407:Bacterial Physiological Phenomena; D018441:Biofilms; D002675:Child, Preschool; D003731:Dental Caries / Q000382:microbiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D064307:Microbiota / Q000502:physiology*; D009055:Mouth / Q000382:microbiology*