Probiotic potential of Lactiplantibacillus plantarum LBK from Koumiss in reducing hyperuricemia through gut microbiota modulation

Hyperuricemia, a metabolic disorder resulting from purine metabolic dysfunction, poses a significant threat to public health. Probiotics, in particular lactic acid bacteria, have the potential to exert therapeutic benefits in the treatment of some metabolic diseases. In this study, 73 lactic acid bacteria were isolated from Koumiss, and their ability to degrade inosine and guanosine, inhibit xanthine oxidase, and other biological properties were assessed through in vitro experiments. The finds revealed that L. plantarum LBK exhibited a significant inhibition of xanthine oxidase activity compared to other strains. It demonstrated superior adherence to the cell surface and tolerance to acid and bile salt compared to all other strains. Subsequently, the strain with the highest overall performance was selected to investigate its potential to lower uric acid in mice with hyperuricemia. Additionally, compared to the model (MOD) group, uric acid, urea nitrogen, and creatinine levels in serum were significantly decreased in the L. plantarum LBK high dose (H-LBK) group. At the same time, L. plantarum LBK alleviated the pathological and inflammatory changes of liver and kidney. L. plantarum LBK treatment acted on kidney gene expression. It up-regulated the gene expression of ATP binding cassette subfamily G member 2 (ABCG2), and down-regulated the gene expression of both uric acid transporter 1 (URAT1) and glucose transporter 9 (GLUT9). 16S rRNA sequencing analysis revealed the effects of L. plantarum LBK treatment on gut microbiota. This treatment decreased the Firmicutes/Bacteroidetes ratio (F/B ratio). It also increased the abundances of lachnospiraceaeNK4A136group, Enterobacteriaceaeᵤncultured, and Parabacteroides. Besides, non-targeted metabolomic analysis revealed alterations in cysteine and methionine, pyrimidine, vitamin B6, and tryptophan metabolism pathways due to the L. plantarum LBK treatment. The treatment also resulted in a reshaping of gut microbial composition and metabolism, ultimately alleviating hyperuricemia in mice. To sum up, L. plantarum LBK can improve the health of patients with hyperuricemia by regulating the gut microbiota, providing a relatively safe approach for consumers to alleviate hyperuricemia.