A Comparative Analysis of Metabolic and Urinary Microbiome Profiles in Patients with Staghorn versus Non-Staghorn Infectious Renal Stones

Objective To investigate the risk factors associated with staghorn calculus formation and the distribution differences in urine microbiota in patients with infectious renal stones. Methods A retrospective analysis was conducted on the clinical data of 201 patients hospitalized in our center from January 2020 to December 2024, who underwent upper urinary tract stone surgery and whose postoperative stone composition analysis indicated the main component was infectious stones. The patients were divided into two groups based on the presence or absence of staghorn calculi. General data, serum biochemical parameters, 24-hour urine metabolic parameters, and urine culture results were collected and compared between the two groups. Univariate and multivariate logistic regression analyses were used to identify independent risk factors for staghorn calculus formation. Results There were no significant differences between the two groups in terms of gender, age, or comorbidities. Serum calcium levels and estimated glomerular filtration rate (eGFR) were significantly higher in the non-staghorn stone group (P < 0.05), and the 24-hour urinary calcium level was also significantly higher than in the staghorn stone group (P = 0.003). Multivariate logistic regression analysis showed that low serum calcium level was a risk factor associated with staghorn calculus formation (P = 0.017, OR 0.016, 95% CI [0.001, 0.473]). Microbiota analysis revealed that the detection rate of Proteus mirabilis was significantly higher in the staghorn stone group compared to the non-staghorn stone group (31.5% vs. 2.4%, P = 0.001). Conclusion Low serum calcium levels and Proteus mirabilis are key factors in the formation of staghorn calculi. Clinically, attention should be paid to monitoring blood calcium levels and controlling urinary tract infections in patients with infectious stones to prevent the occurrence and progression of staghorn calculi and to protect renal function.