Combined oral and peripheral blood detection of Porphyromonas gingivalis associates with coronary heart disease and gut microbiota alterations in a coronary angiography cohort

Background Periodontal pathogens are associated with cardiovascular disease, but clinical evidence linking Porphyromonas gingivalis (Pg) detection with coronary heart disease (CHD) and gut microbiota features remains limited. This study evaluated associations between oral and peripheral blood Pg detection status, CHD prevalence and exploratory gut microbiota characteristics in participants undergoing coronary angiography (CAG).Materials and methods This analytical cross-sectional study included 165 CAG participants, including 124 patients with CAG-confirmed CHD and 41 non-CHD controls. Oral and peripheral blood Pg were detected by TaqMan quantitative polymerase chain reaction. Modified Poisson regression with robust standard errors was used to estimate adjusted prevalence ratios (PRs). Gut microbiota profiles were assessed by 16S rRNA gene sequencing.Results Oral Pg positivity was more frequent in CHD participants than in non-CHD controls and remained associated with CHD in the primary adjusted model (PR = 1.237, 95% CI 1.044–1.465). The oral+/blood+ group showed the strongest association with CHD prevalence (PR = 1.362, 95% CI 1.099–1.688). Five FDR-significant ASVs were enriched in oral Pg-positive participants, whereas predicted pathways were not significant after FDR correction.Conclusions Oral Pg positivity, especially combined oral and peripheral blood Pg nucleic acid positivity, was associated with CHD prevalence in this CAG-defined cohort.