Microbiota in the oral subgingival biofilm is associated with obesity in adolescence.

To test the hypothesis whether microbiota in oral biofilm is linked with obesity
in adolescents we designed this cross-sectional study. Obese adolescents (n = 29)
with a mean age of 14.7 years and normal weight subjects (n = 58) matched by age
and gender were examined with respect to visible plaque index (VPI%) and gingival
inflammation (bleeding on probing (BOP%)). Stimulated saliva was collected. They
answered a questionnaire concerning medical history, medication, oral hygiene
habits, smoking habits, and sociodemographic background. Microbiological samples
taken from the gingival crevice was analyzed by checkerboard DNA-DNA
hybridization technique. The sum of bacterial cells in subgingival biofilm was
significantly associated with obesity (P < 0.001). The link between sum of
bacterial cells and obesity was not confounded by any of the studied variables
(chronic disease, medication, VPI%, BOP%, flow rate of whole saliva, or meal
frequency). Totally 23 bacterial species were present in approximately threefold
higher amounts, on average, in obese subjects compared with normal weight
controls. Of the Proteobacteria phylum, Campylobacter rectus and Neisseria mucosa
were present in sixfold higher amounts among obese subjects. The association
between obesity and sum of bacterial cells in oral subgingival biofilm indicates
a possible link between oral microbiota and obesity in adolescents.