Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2017

Are adverse pregnancy outcomes linked to periodontitis influenced by changes in the gut microbiome? (#31)

Matthew Macowan 1 2 3 , Keyuan Tian 4 , Rebecca Wilson 5 , Claus Christophersen 6 , Tracy Fitzsimmons 4 , Richard Bright 4 , Claire Roberts 5 , Stephen Kidd 2 3 7 , Peter Zilm 4
  1. Molecular and Cellular Biology, University of Adelaide, Adelaide, South Australia, Australia
  2. Research Centre for Infectious Diseases, Adelaide, South Australia, Australia
  3. Australian Centre for Antimicrobial Resistance Ecology, Adelaide, South Australia, Australia
  4. School of Dentistry, University of Adelaide, Adelaide, South Australia, Australia
  5. Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia
  6. School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia, Australia
  7. Molecular and Cellular Biology, University of Adelaide, Adelaide, South Australia, Australia

The effect of periodontitis on adverse birth outcomes is ambiguous. We hypothesise that the increase in oral pathogens may cause a dysbiosis in the gut microbiome and affect pregnancy outcomes.

Aim: To determine whether induced periodontitis in pregnant mice leads to alterations in the gut microbiome that may result in adverse pregnancy outcomes.

Experimental approach: Periodontitis was induced in pregnant mice using an inoculum of Fusobacterium nucleatum and Porphyromonas gingivalis. At day 18 of gestation, pregnancy outcomes were recorded, F. nucleatum and P. gingivalis presence was assessed by PCR, inflammatory mediators were assessed by multiplex analysis, and alveolar bone loss was assessed using micro-CT. Jejunum and colon sections were stained and examined for inflammation. Genomic DNA from caecum contents and faeces were extracted, and amplicon metagenomics targeting the V4 region of the 16S rRNA was performed on the Illumina MiSeq platform.

Results: Increased distance between the cemento-enamel junction and alveolar bone crest confirmed periodontitis induction. Both foetuses and placentas from mothers with induced periodontitis were significantly heavier compared to controls, however their weight ratios remained unchanged. Microbial composition analysis revealed that both induction of periodontitis and pregnancy status alter the gut microbiota. Periodontitis in pregnant mice was associated with a significant change in the proportions of 21 genera compared to controls. Increased levels of inflammation of the jejunum and colon were also observed in the periodontitis groups irrespective of pregnancy.

Conclusions: The gut microbiome was significantly altered at both the phylum and genus levels following induction of periodontitis and was associated with significantly increased inflammation of the gastrointestinal tract. However, this study found no significant association between periodontal disease – and the subsequent change in gut microbiota – and adverse pregnancy outcomes in mice except for slightly increased foetal and placental weights.