The Subgingival Microbiome, Systemic Inflammation and Insulin Resistance: The Oral Infections, Glucose Intolerance and Insulin Resistance Study

J Clin Periodontol. 2017 Mar;44(3):255-265. doi: 10.1111/jcpe.12664. Epub 2017 Jan 27.


Background: Inflammation might link microbial exposures to insulin resistance. We investigated the cross-sectional association between periodontal microbiota, inflammation and insulin resistance.

Methods: The Oral Infections, Glucose Intolerance and Insulin Resistance Study (ORIGINS) enrolled 152 diabetes-free adults (77% female) aged 20-55 years (mean = 34 ± 10). Three hundred and four subgingival plaque samples were analysed using the Human Oral Microbe Identification Microarray to measure the relative abundances of 379 taxa. C-reactive protein, interleukin-6, tumour necrosis factor-α and adiponectin were assessed from venous blood and their z-scores were summed to create an inflammatory score (IS). Insulin resistance was defined via the HOMA-IR. Associations between the microbiota and both inflammation and HOMA-IR were explored using multivariable linear regressions; mediation analyses assessed the proportion of the association explained by inflammation.

Results: The IS was inversely associated with Actinobacteria and Proteobacteria and positively associated with Firmicutes and TM7 (p-values < 0.05). Proteobacteria levels were associated with insulin resistance (p < 0.05). Inflammation explained 30-98% of the observed associations between levels of Actinobacteria, Proteobacteria or Firmicutes and insulin resistance (p-values < 0.05). Eighteen individual taxa were associated with inflammation (p < 0.05) and 22 with insulin resistance (p < 0.05). No findings for individual taxa met Bonferroni-adjusted statistical significance.

Conclusion: Bacterial measures were related to inflammation and insulin resistance among diabetes-free adults.

Keywords: C-reactive protein; adiponectin; diabetes; inflammation; insulin resistance; interleukin-6; microbiome; microbiota; periodontal; tumour necrosis factor-α.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Female
  • Gingiva / microbiology*
  • Glucose Intolerance
  • Humans
  • Inflammation / microbiology*
  • Insulin Resistance*
  • Male
  • Microbiota*
  • Middle Aged
  • Mouth Diseases / microbiology
  • Young Adult