Lacticaseibacillus paracasei LT12—A Probiotic Strain That Reduces Hyperuricemia via Inhibiting XO Activity and Regulating Renal Uric Acid Transportation Protein

Hyperuricemia (HUA), characterized by elevated serum uric acid (UA) levels, is a key risk factor for gout. In human purine metabolism, approximately 70% of UA is excreted via the kidneys, while the remaining 30% is eliminated through the intestines. Thus, the intestinal microbiota plays a crucial role in regulating UA metabolism through the gut–kidney axis. However, the detailed mechanisms by which the microbiota reduces serum UA levels and supports kidney health remain unclear. In this study, researchers investigated the potential of Lacticaseibacillus paracasei LT12, a strain exhibiting xanthine oxidase (XO) inhibition activity and the ability to degrade inosine and guanosine, in reducing UA levels in a hyperuricemia mouse model. Hyperuricemia was induced by gavaging mice with 300 mg/kg of potassium oxonate and hypoxanthine for two weeks. The subsequent 4-week intervention included five groups: a normal control group, a model group, a positive control group receiving allopurinol (5 mg/kg body weight), a low-dose LT12 group (1.5 × 10⁶ CFU/kg), and a high-dose LT12 group (4.5 × 10⁹ CFU/kg). The results demonstrated that L. paracasei LT12 effectively reduced serum UA levels, inhibited serum and hepatic XO activity, regulated renal uric acid transporter proteins (OAT1, URAT1, GLUT9, and ABCG2), and reduced the abundance of the intestinal pathogenic bacterium Corynebacterium stationis in both the low-dose and high-dose groups. Notably, only the high-dose LT12 group significantly increased gut butyrate levels. In conclusion, L. paracasei LT12 shows promise as a potential probiotic strain for ameliorating hyperuricemia. Future human clinical studies are needed to validate its efficacy.