Elimination of Porphyromonas gingivalis inhibits liver fibrosis and inflammation in NASH

J Clin Periodontol. 2021 Oct;48(10):1367-1378. doi: 10.1111/jcpe.13523. Epub 2021 Aug 9.

Abstract

Aim: Non-alcoholic steatohepatitis (NASH) is a critical liver disease showing potential progression to liver cirrhosis/cancer. Previously, we had reported that odontogenic infection of Porphyromonas gingivalis (P. gingivalis), a major periodontal pathogen, exacerbates fibrosis in NASH through the production of fibrosis mediators such as transforming growth factor-β1 (TGF-β1) and galectin-3. In this study, we determined the effects of therapeutic interventions using antibiotics on NASH progression induced by P. gingivalis odontogenic infection.

Materials and methods: To eliminate P. gingivalis infection, the macrolide antibiotic [azithromycin (AZM)] was applied locally and/or systemically to a high-fat-diet-induced NASH mouse model with P. gingivalis odontogenic infection. After treatment with AZM, liver and periodontal tissues were analysed with focus on inflammation markers such as tumour necrosis factor-α (TNF-α)/Tnf-α and interleukin-1β (IL-1β)/Il-1β, and fibrosis markers such as galectin-3, phosphorylated Smad2 (pSmad2; key signalling molecule of TGF-β1), and the number of hepatic crown-like structures (hCLSs). Further, Non-alcoholic Fatty Liver Disease Activity Score (NAS), a common histological scoring system, and fibrosis area were evaluated.

Results: P. gingivalis odontogenic infection significantly increased the expression of Tnf-α, Il-1β, galectin-3, and pSmad2, the number of hCLSs, and NAS score, whereas the elimination of P. gingivalis odontogenic infection, especially local with or without systemic application, significantly inhibited them.

Conclusion: This study suggests that elimination of P. gingivalis odontogenic infection inhibited NASH progression induced by the infection.

Keywords: Porphyromonas gingivalis; dental infection control; non-alcoholic steatohepatitis; periodontitis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Inflammation
  • Liver Cirrhosis
  • Mice
  • Non-alcoholic Fatty Liver Disease* / drug therapy
  • Porphyromonas gingivalis