To investigate the structural characteristics of gut microbiota in patients with calcium oxalate urinary calculi and to explore the correlation mechanisms underlying serum metabolic, based on an integrated analysis of gut microbiomics and serum metabolomics.

Patients with imaging-confirmed calcium oxalate urinary calculi and healthy controls were enrolled. Fecal samples and fasting serum specimens were collected from all participants. 16S rRNA high-throughput sequencing was applied to analyze gut microbiota structure, and UHPLC-MS/MS was used for targeted metabolomics profiling. Multivariate statistical analyses were performed to identify differentially abundant microbial taxa and metabolites. Spearman correlation analysis was adopted to construct the microbiota-metabolite correlation network.

Compared with the healthy control group, patients with calcium oxalate calculi presented increased species richness of gut microbiota and significantly distinct microbial community structure. In terms of microbial composition, symbiotic bacteria including Bifidobacterium, Blautia, and Roseburia were markedly decreased, while the relative abundances of Bacteroides, Prevotella, and Akkermansia were increased. Metabolomic results indicated obvious disturbances in serum metabolic profiles of patients, which were predominantly characterized by lipid metabolism disorders, abnormal amino acid metabolism, and reduced levels of oxidative stress-related metabolites. Correlation analysis revealed significant correlations between specific gut microbial taxa and multiple differentially expressed metabolites.

Patients with calcium oxalate urinary calculi exhibit gut microbiota dysbiosis and disrupted serum metabolic profiles. These two layers of alteration may interact through multiple interconnected pathways and jointly contribute to the pathogenesis of the disease.