[Screening of novel uric acid-lowering probiotics and evaluation of their probiotic properties]

To address the growing health challenge of hyperuricemia while circumventing or compensating for the limitations of existing clinical treatment options, through a combination of large-scale screening and laboratory-based adaptive evolution, we identified a Lactobacillus acidophilus strain D801 exhibiting robust capacity for uric acid degradation. We then systematically evaluated the probiotic properties of the strain by assessing the in vitro uric acid degradation capacity, gastrointestinal tolerance, auto-aggregation ability, acid and bile salt tolerance, and antibiotic susceptibility. Strain D801 demonstrated a degradation rate of (57.26± 6.52)% for 2.0 mmol/L uric acid in vitro. It exhibited no resistance to the eight tested antibiotics. Furthermore, it displayed strong auto-aggregation ability, with an aggregation rate reaching 97.62% after 3 hours of incubation. The strain maintained the survival rates of (20.83±6.51)% at pH 2.0 and (50.00±16.24)% at pH 3.0 following 3 h exposure. It tolerated up to 0.48% (W/V) sodium deoxycholate, retaining a viable count of 4.0×10⁶ CFU/mL after 3 h. In simulated gastric fluid and intestinal fluid, the strain maintained the survival rates at (102.8±15.56)% and (105.1±3.07)%, respectively. In vivo administration of L. acidophilus D801 significantly attenuated hyperuricemia in mice, reducing the serum uric acid level by 20.65%. Moreover, the strain decreased the xanthine oxidase (XOD) activity by 36.24% and 13.54% in the mouse liver and serum, respectively. Importantly, it reduced the spleen index by 17.09%. The results suggest that strain D801 improves the immune function and alleviates systemic inflammation. The core significance of this study lies in offering a safer approach for hyperuricemia.