The newly-isolated Levilactobacillus brevis LABC170 and Limosilactobacillus fermentum LABC37 with purine nucleosides degradation activity show probiotic efficacy in prevention and treatment of hyperuricemia in mice

Purine nucleosides are recognized as key contributors to hyperuricemia. In this study, we isolated 81 Lactic Acid Bacteria (LAB) from various sources and evaluated their purine nucleosidase (PNase) activity. Among them, Levilactobacillus brevis LABC170 exhibited complete degradation of guanosine and inosine (100 %), while Limosilactobacillus fermentum LABC37 showed high degradation rates (92 ± 1.72 % guanosine, 88 ± 4.6 % inosine). Both strains demonstrated probiotic characteristics, including acid resistance and adhesion to Caco-2 cells. In hyperuricemia-induced mice, LAB administration significantly reduced blood uric acid (hyperuricemia group: 2.7 ± 0.5 mg/dL vs. LAB-treated groups: 1.8 ± 0.2 to 2.2 ± 0.3 mg/dL, p < 0.05). Notably, L. fermentum LABC37, despite lower PNase activity than L. brevis LABC170, was more effective in reducing uric acid when administered before hyperuricemia induction, suggesting probiotic effects beyond PNase activity. These findings highlight the strain-specific variations in PNase activity and the potential application of newly isolated LAB strains in hyperuricemia prevention and treatment.