Screening of Lactic Acid Bacteria with High Uric Acid Lowering Activity and Its Mechanism of Action(高降尿酸活性乳酸菌的筛选及其作用机制)
摘要
The incidence rate of hyperuricemia is increasing worldwide. Uric acid reducing lactic acid bacteria (LAB) could be the new way for the prevention and auxiliary treatment of hyperuricemia. To investigate the underlying mechanism of LAB in reducing uric acid, 20 strains of LAB were selected as the research objects. High performance liquid chromatography(HPLC) was used to screen LAB with the ability to reduce uric acid and the mechanism was explored by determining the active composition of LAB. The results showed that <i>Lacticaseibacillus rhamnosus</i> N1-2, <i>Lacticaseibacillus rhamnosus</i> N1-5,<i>Lactobacillus helveticus</i> LH3, <i>Lactobacillus helveticus</i> T1(1)-1 and <i>Lacticaseibacillus paracasei</i> LP4 exhibited strong hypouricemic activity(41.96%, 42.50%, 44.18%, 46.22% and 37.33%, respectively) <i>in vitro</i>. By studying the components of 5 strains of lactobacillus and exploring their mechanism of UA-lowering, it was found that, the uric acid lowering effect of live bacteria was significantly higher than that of dead bacteria(<i>P</i><0.05), but the uric acid lowering effect of live bacteria cell lysates and dead bacteria cell lysates was similar and was higher than the whole live bacteria(<i>P</i><0.05). Furthermore, the uric acid lowering effect of 5 strains of lactobacillus was not related to the cell wall, extracellular secretions, and other components in cell lysate. The uric acid lowering effect was also unrelated to the activity of intracellular uricase, which was widely believed to play a key role in most studies. Through the protoplast adsorption experiment and the scanning electron microscope experiment after the protoplast adsorption of uric acid, the 5 lactobacillus strains showed a close relationship between the reduction of uric acid and the cell membrane. The study aimed to provide a theoretical basis for the screening and application of LAB for reducing urine.(高尿酸血症发病率在全球范围内呈上升趋势,通过乳酸菌降尿酸已成为防治高尿酸血症的一种新途径。为研究乳酸菌降尿酸的作用机制,以20株乳酸菌为研究对象,