Screening and Validation of Uric Acid-Lowering LAB from Trachemys scripta elegans

Hyperuricemia (HUA), a metabolic disorder characterized by elevated serum uric acid (UA) levels resulting from purine metabolism dysfunction, is closely associated with gout, hypertension, and cardiovascular diseases. Current pharmacological treatments are frequently associated with adverse effects, underscoring the need for safer alternatives. In this study, lactic acid bacteria (LAB) with UA-lowering potential were isolated from the intestine of Trachemys scripta elegans and screened through a multi-indicator approach combining UA degradation, purine metabolism, and xanthine oxidase (XOD) inhibition assays. Five candidate strains were identified, among which SL-5 exhibited the most outstanding performance, degrading 76.19% of UA, 96.62% of adenosine, 83.50% of guanosine, and 99.29% of hypoxanthine, while inhibiting XOD activity by 71.51%, demonstrating a dual capacity to both degrade purines and suppress UA synthesis. In vivo validation using a C. elegans hyperuricemia model confirmed that SL-5 reduced UA levels by 52.50%. Physiological characterization further revealed robust growth, high self-aggregation capacity (>80%), strong stress tolerance, and potent antioxidant activity. 16S rDNA sequencing identified SL-5 as Enterococcus hirae. This study establishes an effective screening framework and provides a novel strain resource for the development of enzyme-based interventions against hyperuricemia.