Nonsurgical periodontal treatment improved the abnormal trimethylamine n-oxide metabolism in Apoe-/- mice with periodontitis.

BACKGROUND AND AIMS: Periodontitis aggravated atherosclerosis and the plasma level of the atherosclerosis virulence factor trimethylamine n-oxide (TMAO) increased in Apoe-/- mice was reported. Nonsurgical periodontal treatment (NSPT) is an important treatment method for periodontitis. Therefore, we investigate how NSPT ameliorates the metabolism of TMAO in Apoe-/- mice with periodontitis.

METHODS

Six-week-old Apoe-/- mice were randomly divided into three groups: the control group (no treatment), the LIGPG (ligation with silk threads soaked in Porphyromonas gingivalis) group, and the NSPT group (removing the ligature thread and scaling). Quantifications of TMAO in plasma were performed. Mouse maxillae were scanned using micro-CT to measure alveolar bone absorption. Livers and intestines were analyzed for gene and protein expression. Mouse feces at 0 and 8 weeks were collected and further analyzed using 16S rRNA gene sequencing for gut microbiota.

RESULTS

The TMAO concentration in the NSPT group was significantly lower than that in the LIGPG group. The systemic inflammatory environment caused by periodontitis was improved through NSPT, especially in the small intestine. The composition and abundance of the intestinal microflora changed after treatment. Spearman correlation analysis between TMAO and different bacteria revealed that plasma TMAO levels were significantly positively correlated with Bacteroides, Helicobacter, Lachnoclostridium and Lactobacillus and significantly negatively correlated with Parasutterella and Ileibacterium.

CONCLUSIONS

NSPT alleviated the periodontitis-induced increase in TMAO levels, which might be associated with changes in the intestinal microbiota, especially Bacteroides, Helicobacter, Lachnoclostridium, Lactobacillus, Parasutterella and Ileibacterium. Our study provides new insights for the study of NSPT and cardiovascular diseases.