Abstract
INTRODUCTION: Gallstone disease (GSD) is a common hepatobiliary disorder influenced by bile composition, biliary drainage, and gallbladder motility. Emerging evidence suggests that oral microbiota may contribute to GSD development, but its role remains unclear. This study explores salivary microbiome alterations in GSD patients and their potential clinical relevance. METHODS: This study enrolled 58 GSD patients and 10 age-matched healthy controls. Salivary microbiome profiles were characterized using high-resolution 16S rRNA amplicon sequencing. All participants underwent comprehensive clinical evaluations including physical examinations, oral health assessments, anthropometric measurements, and fasting venous blood sampling for serum biochemical analysis. A multi-dimensional approach was applied to investigate host-microbiome interactions and their potential role in GSD pathogenesis. RESULTS: Comparative analysis revealed significant microbial divergence between GSD patients and healthy controls, characterized by increased α-diversity indices and distinct β-diversity clustering. The linear discriminant analysis effect size (LEfSe) analysis identified 65 differentially abundant taxonomic features across multiple phylogenetic levels, including 7 phyla, 9 classes, 11 orders, 16 families, and 22 genera, representing 550 operational taxonomic units (OTUs). Notably, Veillonella, Neisseria, Prevotella, and Lachnoanaerobaculum were markedly enriched in the GSD cohort. The developed eXtreme Gradient Boosting (XGBoost) diagnostic model demonstrated exceptional discriminatory capacity, achieving a mean AUC of 0.994 under rigorous fivefold cross-validation. Redundancy analysis (RDA) and Spearman correlation analysis showed strong associations between microbial community structure and key biochemical markers, including chenodeoxycholic acid (CDCA) and alkaline phosphatase (ALP). Functional prediction using PICRUSt2 indicated substantial metabolic pathway alterations in GSD patients, particularly enhanced activity in energy production, amino acid metabolism, and secondary metabolite biosynthesis. CONCLUSIONS: Salivary microbiome dysbiosis in GSD patients demonstrated significant associations with disrupted bile acid homeostasis, suggesting a potential role of the oral microbiota in modulating lithogenic processes. The markedly altered microbial signatures may contribute to GSD pathogenesis, while the XGBoost-based diagnostic model shows considerable promise as a noninvasive tool for GSD detection.