Analysis of gut microbiota in patients with AVS and identification of potential biomarkers: a cross-sectional study

This study evaluated the characteristics of the gut microbial (GM) in patients with aortic valve stenosis (AVS). Thirty patients diagnosed with AVS and 30 healthy controls (HC) were included. Fecal samples were obtained for high-throughput 16S rDNA sequencing. Bacterial diversity was assessed using QIIME and R software. Potential biomarkers were identified using the random forest model. The model performance was evaluated using receiver operating characteristic (ROC) curves and decision curve analysis. Relationships between the GM and clinical characteristics of participants were examined using the Spearman's correlation. The composition of GM, measured by beta diversity, significantly differed between the two groups (Adonis, <i>P</i> = 0.001), indicating distinct microbial community structures in AVS patients compared to HC. At the phylum level, the <i>Firmicutes</i>/<i>Bacteroidetes</i> (F/B) ratio was significantly lower in the AVS group compared to the HC group (<i>P</i> = 0.031, Wilcoxon test). At the genus level, the relative abundance of short-chain fatty acids (SCFAs)-producing bacteria, including <i>Lachnospiraceae</i>, <i>Prevotellaceae</i>, and <i>Enterococcus,</i> was significantly reduced. Twenty-four genera were identified as potential biomarkers using the nested cross-validation feature of the random forest model (86.67% accuracy in cross-validation). The area under the receiver operating characteristic curve (AUC) was 0.94 (95% CI = 0.79-1.00). The decision curve analysis highlighted the practical utility of the model in clinical settings. Patients with AVS exhibited alterations in GM, particularly a reduction in the SCFAs-producing bacteria. The distinct GM profiles demonstrated strong predictive capabilities for AVS and were related to the worsening of clinical indicators. Notably, 24 genera may serve as potential biomarkers and predictors in clinical settings.IMPORTANCEDysbiosis of GM contributes to cardiovascular diseases; however, research on GM alterations in patients with aortic valve stenosis (AVS) is limited. The study aimed to conduct a cross-sectional study matched for age, sex, body mass index (BMI), and patient geographic region, to analyze the GM in patients with AVS, to identify potential biomarkers, and to assess the effectiveness of clinical prediction. If this correlation is confirmed, the GM may be used for risk stratification and identification of potential therapeutic targets.CLINICAL TRIALSThis clinical study was registered with the China Clinical Trials Registration Center (No. ChiCTR2400081198).