Dysbiosis of Oral and Gut Microbiota and Its Association with Metabolites in Patients with Different Degrees of Coronary Artery Stenosis
Coronary atherosclerotic heart disease (CAD) is a leading cause of morbidity and mortality worldwide. It arises from the buildup of coronary atherosclerosis (CAS) plaques, leading to coronary stenosis (CS) and occlusion, which ultimately results in myocardial ischemia, hypoxia, or necrosis. Recent studies have highlighted the significant role of alterations in oral and gut microbiota in the pathogenesis of CAS. Dysbiosis, or microbial imbalance, triggers oxidative stress, inflammatory responses, and metabolic disturbances, initiating the atherosclerotic process. However, a systematic understanding of the distinctions in oral and gut microbial traits and metabolomic features among CAS patients with varying degrees of coronary artery stenosis remains limited. This study aims to elucidate these differences and explore their potential implications for early diagnosis and precise treatment of CAS.
Study Design and Methodology
The study involved 63 CAS patients and 31 controls. Participants were divided into three groups based on the degree of coronary stenosis: the Minimal and Mild Coronary Stenosis (MMCS) group (n = 33), with stenosis 50% in at least one coronary segment; and the control group (n = 31), which included individuals with negative results in coronary computed tomography or coronary angiography. Blood samples were collected on the first day of hospitalization, and untargeted metabolomics analysis was performed using Liquid Chromatography combined with Tandem Mass Spectrometry (LC-MS/MS). Genomic DNA was extracted from oral and fecal samples, and the V3–V4 region of bacterial 16S rRNA was amplified. Raw reads were subjected to quality analysis, and a multi-omics approach was employed to explore the potential cooperative regulation of metabolism by oral and gut microbiota in CAS patients with varying degrees of stenosis. Statistical analyses included the Wilcoxon rank-sum test, one-way analysis of variance, and pairwise comparisons, with a P value <0.05 considered statistically significant.
Oral and Gut Microbial Community Analysis
The study first evaluated the alpha diversity of the oral and gut microbial communities, representing microbial richness and evenness. No statistically significant differences were observed in the alpha diversity of the oral microbial community among the three groups. However, the weighted-unifrac-based beta diversity of the oral microbial community differed significantly between the MMCS and control groups (P <0.001), as well as between the MSCS and control groups (P <0.001). In contrast, the gut microbial community alpha diversity, assessed using the sobs index, was highest in the control group and significantly different from the MMCS and MSCS groups (control group vs. MMCS group, P = 0.041; control group vs. MSCS group, P = 0.005; MMCS group vs. MSCS group, P = 0.027). The weighted-unifrac-based beta diversity of the gut microbial community also showed statistically significant differences between the MMCS and control group, the MSCS and control group, and the MMCS and MSCS group (control group vs. MMCS group, P <0.001; control group vs. MSCS group, P <0.001; MMCS group vs. MSCS group, P <0.001).
Differential Abundance of Microbial Genera
The study identified significantly differential abundance of microbial genera across groups using the Wilcoxon rank-sum test and Linear Discriminant Analysis Effect Size (LEfSe) analysis. In saliva samples, the MMCS group exhibited significantly increased levels of the genus Mobiluncus and significantly decreased levels of the genus Tessaracoccus compared to the control group (P <0.05). The MSCS group showed significantly increased levels of the genus Howardella in saliva, while the order Cardiobacteriales and Burkholderiales, family Cardiobacteriaceae and Burkholderiaceae, and genus Cardiobacterium and Lautropia were significantly lower (P <0.05). In fecal samples, the MMCS group exhibited significantly increased levels of the genus Fusicatenibacter and significantly decreased levels of the genus Olsenella, Anaerococcus, and Intestinibacter compared to the control group (P <0.05). The MSCS group showed significantly increased levels of the genus Desulfovibrio, Moraxella, and Actinomyces and significantly decreased levels of the genus Ilumatobacter, Aeromonas, Litorilinea, and Loktanella in fecal samples compared to the control group (P <0.05).
Metabolomic Profiling and Biomarker Identification
Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA) models of metabolite profiling data revealed significantly different metabolite profiles in patients with MMCS and MSCS compared to control subjects. The study identified 64 different metabolites in the MMCS group and 170 different metabolites in the MSCS group (screening criteria for differential metabolites: level ≤4, variable importance in projection ≥1, fold change ≥1.2 or ≤0.83, P <0.05). Receiver Operating Characteristic (ROC) curve analysis was used to identify metabolic biomarkers of MMCS and MSCS in serum. Differential metabolites with predictive value for MMCS included verrucarol, 3-hydroxytetradecanedioic acid (3-HA), and geranylacetone, among others. For MSCS, predictive metabolites included glucuronic acid-3,6-lactone, 3-HA, 1-oleoyl-rac-glycerol, and athamantin, among others.
Inflammation and Metabolic Pathways
Inflammation serves as a primary mechanism in the regulation of CAS. The study confirmed that pathogenic bacteria involved in periodontitis may participate in the pathogenesis of CAS through direct inflammatory responses. The clinical attachment level (CAL), reflecting periodontal health, increased in the MMCS group and further increased in the MSCS group compared to the control group. Interleukin-6 (IL-6), a pro-inflammatory cytokine, and 3-HA, associated with dysregulation of fatty acid metabolism, were elevated in the MMCS and MSCS groups. Docosahexaenoic acid (DHA), which exerts potential anti-obesity effects by reducing the secretion of inflammatory adipokines, oxidative stress, lipolysis, and apoptosis, was significantly decreased only in the MSCS group. N-arachidonoyl dopamine (N-ADA), possessing anti-inflammatory properties, was lower in the MMCS and MSCS groups compared to the control group.
Correlation Analysis
Spearman correlation analysis was used to investigate the correlations between the oral and gut microbiome and serum metabolites 3-HA, N-ADA, DHA, and IL-6 in MMCS and MSCS patients. In the saliva of MMCS patients, the genus Mobiluncus exhibited positive correlations with IL-6 and 3-HA (r = 0.43 and r = 0.50, P <0.05), while the genus Tessaracoccus exhibited a positive correlation with N-ADA (r = 0.28, P <0.05). In the feces of MMCS patients, the genus Fusicatenibacter showed positive correlations with IL-6 (r = 0.36, P <0.05), the genus Anaerococcus exhibited negative correlations with 3-HA, and Intestinibacter exhibited positive correlations with N-ADA (r = –0.37 and r = 0.32, P <0.05). In the saliva of MSCS patients, the genus Howardella exhibited positive correlations with IL-6 and 3-HA, while the genus Cardiobacterium and Lautropia exhibited positive correlations with DHA. In the fecal samples of MSCS patients, the genus Actinomyces and Moraxella were positively correlated with 3-HA and IL-6, while the genus Litorilinea, Loktanella, and Ilumatobacter were negatively correlated with 3-HA and IL-6. The genus Desulfovibrio displayed negative correlations with DHA and positive correlations with N-ADA.
Conclusion
The findings of this study suggest that the composition of oral and intestinal microorganisms and metabolites is statistically significantly different between controls and patients with CAS-related CS. These microorganisms and metabolites may further change with the severity of CS. Oral and gut microorganisms may play a role in the development of MMCS and MSCS by interdependently regulating inflammation-related metabolites such as IL-6, 3-HA, DHA, and N-ADA. Maintaining the homeostasis of oral and gut microbiota and reducing the abundance of Mobiluncus, Fusicatenibacter, Actinomyces, Moraxella, and Desulfovibrio in patients with CAS may aid in preventing the occurrence of inflammation and progression of CAS. However, the study’s preliminary nature and small sample size are limitations, and expanding the study population would enhance the robustness of the results.
doi.org/10.1097/CM9.0000000000002943
Was this helpful?
0 / 0