Comparative effects of periodontitis – versus periodontal health-derived saliva on systemic lipid metabolism in mice: mediation through oral–gut axis

Background Periodontitis is linked to dyslipidaemia, but the mechanism still requires further investigation.Objective This study aimed to investigate the periodontitis-dyslipidaemia interplay, comparing the impact of periodontitis-associated versus healthy salivary microbiota on systemic lipid metabolism in mice via the oral–gut axis.Design NHANES analysis established epidemiological link. ApoE−/− mice received salivary microbiota from periodontally healthy (A-PH) or severe periodontitis (A-SP) donors. Serum lipids and gut microbiota were assessed; correlations between microbial shifts and lipid changes were evaluated.Results NHANES confirmed significant association between self-reported physician-diagnosed bone loss around teeth and hypercholesterolemia (OR=1.266). A-SP mice exhibited higher TC, LDL and non-HDL compared with A-PH group. Gut dysbiosis featured increased proinflammatory genera (Helicobacter and Prevotella) and reduced beneficial bacteria (Mucispirillum, Parasutterella, and Barnesiella). Prevotella positively correlated with TC, Helicobacter with LDL; beneficial genera negatively correlated with atherogenic lipids.Conclusions Collectively, building upon the NHANES link, our findings demonstrate that the salivary microbiome from periodontitis patients, compared to that from healthy individuals, disrupts systemic lipid metabolism and induces gut dysbiosis in mice. The correlation between specific gut microbial shifts and atherogenic lipid profiles provides experimental support for the mediating role of the oral‒gut axis in linking periodontitis to hyperlipidaemia.