Lactococcus lactis SWU-HX39 for relieving hyperuricemia

Abstract

The present application discloses a lactic acid pediococcus SWU-HX39 with the function of reducing uric acid, and the classification name is lactic acid pediococcus (Pediococcus acidilactici) Pediococcus acidilactici ), which is preserved in the China General Microbiological Culture Collection Center, with the preservation number of CGMCC No.33055, the preservation date of December 13, 2024, and the preservation address of No.3, Xili, Beichen West Road, Chaoyang District, Beijing. The lactic acid pediococcus SWU-HX39 can relieve the kidney damage caused by high uric acid, reduce the synthesis of uric acid, lower the concentration of uric acid in blood, improve the excretion of uric acid in the body, reduce the reabsorption of uric acid in the body, and achieve the effect of reducing uric acid. In addition, SWU-HX39 can reduce the expression of LPS and the expression of inflammatory factors IL-1beta, IL-6 and TNF alpha. That is, it has the functions of anti-inflammation and relieving liver inflammation, and can also increase the content of SCFAs in the body of patients with high uric acid, especially propionic acid, so as to reduce the uric acid level and improve the abnormal uric acid content.

Description

Technical Field

[0001] This invention relates to the field of microbial technology, specifically to a strain of *Pediococcus lactis* SWU-HX39 that can alleviate hyperuricemia. Background Technology

[0002] Hyperuricemia is a disease caused by purine metabolism disorders, mainly characterized by increased uric acid synthesis in the body or decreased uric acid excretion by the kidneys, or both. This condition is not only closely related to gout but can also trigger systemic diseases such as cardiovascular disease, kidney disease, and metabolic syndrome. Its development is often accompanied by metabolic disorders, especially those involving the liver, kidneys, and intestines, reflecting complex physiological and pathological processes. Studies have shown that the roles of the liver and kidneys in purine metabolism directly affect uric acid accumulation. When blood uric acid levels are too high, uric acid crystallization and precipitation can lead to complications such as gout, particularly in the joints and cartilage. Therefore, gout patients urgently need effective measures to lower their uric acid levels.

[0003] Treatment for hyperuricemia mainly includes two approaches: pharmacological therapy and non-pharmacological therapy. Pharmacological therapy commonly uses drugs that promote uric acid excretion, such as benzbromarone, or drugs that inhibit uric acid synthesis, such as allopurinol. However, pharmacological therapy may be accompanied by clinical side effects and financial burden. In contrast, non-pharmacological therapy, through reducing the intake of high-purine foods and supplementing with probiotics that help break down uric acid, shows novelty and potential, becoming a promising alternative or adjunctive treatment strategy.

[0004] Probiotics are a class of bacteria that are beneficial to the host's health. Studies have shown that lactic acid bacteria alleviate hyperuricemia by inhibiting the activity of xanthine oxidase; ingestion of lactobacillus can promote the conversion of compounds in the intestines of hyperuricemic mice and reduce purine levels. Furthermore, it also reduces purine concentrations in the liver and inhibits xanthine oxidase activity. A large body of clinical and epidemiological evidence suggests that some probiotics can lower serum uric acid levels, but the effects and mechanisms of uric acid reduction vary among different probiotics. The application of probiotics in the treatment of hyperuricemia is still in its early stages. Due to the wide variety of probiotics, with different mechanisms of action, intestinal colonization capabilities, and potential pathogenicity, their uric acid-lowering effects in the body also vary significantly. Therefore, there is an urgent need to find safe and highly effective lactic acid bacteria that can lower serum uric acid concentrations. Summary of the Invention

[0005] The purpose of this invention is to provide a strain of *Pediococcus lactis* that can alleviate hyperuricemia. Animal experiments have demonstrated its effects in reducing serum uric acid concentration, anti-inflammation, regulating intestinal microbiota, promoting uric acid excretion, and improving renal metabolism.

[0006] Another object of the present invention is to provide the application of the above-mentioned Pediococcus lactis.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A strain of *Pediococcus lactis* SWU-HX39 with uric acid-lowering function, characterized in that: the taxonomic name of the *Pediococcus lactis* is *Pediococcus lactis* (… Pediococcus acidilactici SWU-HX39 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 33055, on December 13, 2024, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0009] Pediococcus lactis SWU-HX39 effectively inhibits XOD activity in the liver and reduces the levels of creatinine and urea nitrogen in mouse serum, thereby reducing the uric acid content in the blood of patients.

[0010] In addition, Porphyromonas lactis SWU-HX39 can promote the excretion of uric acid by patients, while inhibiting and reducing the body's reabsorption of uric acid.

[0011] Lactococcus SWU-HX39 can alleviate hyperuricemia by regulating LPS and liver inflammation, and has a significant anti-inflammatory effect.

[0012] Pediococcus lactis SWU-HX39 can also regulate the level of the gut microbiota and increase the content of SCFAs in the body.

[0013] The application of the above-mentioned Pyrococcus SWU-HX39 in the preparation of drugs that lower uric acid.

[0014] The aforementioned *Pediococcus lactis* SWU-HX39 is used in the preparation of anti-inflammatory drugs.

[0015] The above-mentioned application of Porphyromonas lactis SWU-HX39 in the preparation of drugs or foods that regulate intestinal flora.

[0016] The present invention has the following technical effects: This invention, *Pediococcus lactis* SWU-HX39, can alleviate kidney damage caused by hyperuricemia; it can also reduce uric acid synthesis, lower blood uric acid concentration, and simultaneously improve the body's ability to excrete uric acid and reduce its reabsorption, achieving a dual effect of lowering uric acid. Furthermore, SWU-HX39 can reduce LPS expression and also decrease the expression of inflammatory factors IL-1β, IL-6, and TNF-α. Therefore, it has anti-inflammatory effects, reduces liver inflammation, and can also increase the content of SCFAs in patients with hyperuricemia, especially propionic acid, thereby lowering uric acid levels and improving abnormal uric acid levels. Attached Figure Description

[0017] Figure 1Images of colony morphology and staining characteristics of SWU-HX39.

[0018] Figure 2 Results of the SWU-HX39 simulated gastrointestinal fluid tolerance test.

[0019] Figure 3 Figure showing the change in body weight in hyperuricemic mice after intervention with SWU-HX39.

[0020] Figure 4 : Changes in kidney index in hyperuricemic mice treated with SWU-HX39.

[0021] Figure 5 HE staining of kidney tissue sections from hyperuricemic mice treated with SWU-HX39.

[0022] Figure 6 Changes in serum UA (uric acid), CRE (creatinine), BUN (blood urea nitrogen) levels, as well as liver and serum XOD (xanthine oxidase) activity levels in hyperuricemic mice treated with SWU-HX39.

[0023] Figure 7 : Changes in TNF-α, IL-1β, IL-6 and LPS levels in hyperuricemic mice treated with SWU-HX39.

[0024] Figure 8 : Bar chart of relative abundance of species at the genus level in SWU-HX39-treated hyperuricemic mice.

[0025] Figure 9 The content of SCFAs in cecal contents after SWU-HX39 intervention.

[0026] Figure 10 Expression of uric acid transport-related genes in the kidneys of hyperuricemic mice treated with SWU-HX39. Detailed Implementation

[0027] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0028] Example 1 Strains are isolated, screened, and identified. Multiple strains of lactic acid bacteria with excellent acid resistance were isolated from cheese and kimchi.

[0029] The bacterial strain was inoculated at 2% (v / v) into fresh MRS liquid medium and incubated at 37 °C for 24 h. 2 mL of the bacterial suspension was centrifuged at 4000 r / min for 10 min and washed three times with 1 mL of 0.85% NaCl solution. The bacterial suspension concentration was adjusted to 10 using a bacterial turbidimeter. 9 CFU / mL. Take 1 mL of bacterial suspension, centrifuge at 4000 r / min for 10 min, discard the supernatant, resuspend the cells in 750 μL of 1 mmol / L inosine-guanosine solution, and incubate at 37 ℃ for 120 min. After incubation, centrifuge at 4000 r / min for 10 min, collect the supernatant, and terminate the reaction by adding HClO4 solution at a volume ratio of supernatant to 0.1 M HClO4 of 9:1. After mixing, filter through a 0.22 μm filter membrane for analysis.

[0030] The residual inosine and guanosine in the solution were determined using a high-performance liquid chromatography (HPLC) system. Chromatographic conditions: a ThermoFisher-C18 reversed-phase column (4.6 mm × 250 mm, 5 μm); a mobile phase of 10 mmol / L potassium dihydrogen phosphate solution (pH 5.0) and methanol (90:10 v / v); a flow rate of 1 mL / min; a column temperature of 25 °C; a wavelength of 254 nm; and an elution time of 30 min. The degradation rate was calculated using the formula.

[0031] Degradation rate = ×100% In the formula, C0 is the initial concentration of the guanosine (inosine) standard solution, mmol / L; C is the remaining concentration of the guanosine (inosine) standard solution after the reaction, mmol / L.

[0032] Through calculation and screening, a strain with excellent degradation ability of inosine and guanosine was obtained, with an inosine degradation rate of 82.75%±4.74 and a guanosine degradation rate of 78.80%±4.28.

[0033] The purified strain was removed from the glycerol tube and inoculated into fresh MRS liquid medium at 2% (v / v) and incubated at 37 °C for 24 h. After two generations of activation, single colonies were isolated by streaking on MRS plates with a sterile inoculation loop. The purified isolates were examined under a microscope and Gram staining was performed for observation. The results are as follows: Figure 1 As shown.

[0034] The strain was further identified by 16S rDNA sequencing after multiple plate isolations. The 16S rDNA of the strain was amplified by PCR and sequenced, and the sequence was compared and analyzed using the BLAST (Basic Local Alignment Search Tool) program in the NCBI database. Sequence comparison confirmed it to be *Pediococcus lactis*.

[0035] The strain was named SWU-HX39 and deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 33055, on December 13, 2024, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

[0036] For strain SWU-HX39's tolerance to simulated gastrointestinal fluids: Simulated gastric fluid: Pepsin was added to sterile PBS (0.1 mol / L, pH 2.5) to a final concentration of 3 g / L; simulated intestinal fluid: Trypsin was added to sterile PBS (0.1 mol / L, pH 8.0) to a final concentration of 1 g / L. Lactic acid bacteria activated for two generations were cultured overnight, washed twice with sterile physiological saline (0.85% NaCl, w / v), and resuspended. They were then inoculated into simulated gastric fluid to achieve a final bacterial concentration of 10⁸ CFU / mL. After incubation at 37 °C for 3 h, bacterial culture was serially diluted 10-fold with sterile physiological saline at 0 and 3 h. 100 μL of each appropriate serial dilution was plated onto MRS plates and incubated at 37 °C for 48 h before counting viable cells. Then, 1 mL of culture was inoculated into 9 mL of simulated intestinal fluid and incubated at 37 °C for 8 h. At 0, 2, 4, and 8 h, the bacterial culture was serially diluted 10-fold with sterile physiological saline. 100 μL of each appropriate serial dilution was plated onto MRS plates and incubated at 37 °C for 48 h before calculating the viable count. The survival rate of lactic acid bacteria in simulated gastrointestinal fluid was calculated using the following formula:

[0037] Nt represents the number of viable lactic acid bacteria at different times after treatment with simulated gastrointestinal fluid; N0 represents the initial number of viable lactic acid bacteria.

[0038] The results are as follows Figure 2 As shown, Pediococcus lactis SWU-HX39 exhibits excellent tolerance in simulated gastric and intestinal fluids.

[0039] Hemolytic activity test: Pediococcus lactis SWU-HX39 was inoculated onto Columbia agar plates containing 5% sterile defibrinated sheep blood and incubated at 37°C for 48 h. Hemolytic activity was classified into three types: α-hemolysis (green area), β-hemolysis (clear transparent area), and γ-hemolysis (no hemolytic area, i.e., negative). The results indicate that Pediococcus lactis SWU-HX39 has no hemolytic activity, demonstrating its safety.

[0040] Example 2 Animal experiments were conducted to test the effects and uric acid-lowering mechanism of Pyotrophic Lactococcus SWU-HX39 (hereinafter referred to as HX39 in the attached figures): SPF-grade male Kunming mice, 6 weeks old and weighing 27±2 g, were purchased from Hunan Slack Jingda Experimental Animal Co., Ltd. The animal laboratory was an SPF-grade clean, standard pathogen-free environment. Hulling conditions included an ambient temperature of 25±1 ℃, humidity of 60±10%, and a light / dark ratio of 12 / 12. Mice were fed standard growing feed, with sawdust as bedding. All mice had free access to water, and all procedures strictly adhered to experimental ethical principles and requirements. Mice were normally housed for 7 days to allow for environmental acclimatization, and then divided into a blank control group, a model group, an HX39 group, and a positive control group (allopurinol group), with 8 mice in each group. A chronic renal failure model was established using a combination of adenine and potassium oxonate. Based on preliminary experimental results, the model was improved, and a suspension of 75 mg / kg adenine and 220 mg / kg potassium oxonate was administered via gavage in 0.5% sodium carboxymethyl cellulose solution. The gavage volume was 200 μL, administered daily at 9:00 AM. The HX39 group was mice administered 100 μL of 10 mol / L gavage 1 hour later. 9 CFU of the SWU-HX39 strain was administered as a suspension. The allopurinol group was fed 8 mg / kg of allopurinol, while the control and model groups received only saline solution. After gavage, any remaining medication was discarded without recycling to avoid repeated freeze-thaw cycles affecting the experimental results. During the 24-day animal experiment, measurements were taken daily at 11:00 AM.

[0041] Before administration on day 24, the mice were fasted for 16 hours but allowed to drink water. (1) Fresh urine and feces were collected and quickly placed on ice, then transferred to a -80 ℃ freezer for storage. (2) The mice were enucleated and blood was collected from the orbital area. The collected blood was centrifuged at 3500 r / min for 15 min at 4 ℃, and the serum was stored in a -80 ℃ freezer for later use. (3) The mice were euthanized by cervical dislocation and dissected to obtain the contents of the liver, kidneys, small intestine, colon and cecum.

[0042] (1) Organ index measurement: Mouse organs and tissues should be rinsed in pre-cooled physiological saline at 4°C to remove blood and adhering connective tissue. After being wiped dry with filter paper, they should be weighed and the organ index calculated according to the following formula:

[0043] During the experiment, the normal group mice exhibited glossy fur, normal excretory function, and steady weight gain, demonstrating a healthy physiological state. Conversely, the model group mice showed dull fur, reduced activity, and abnormally increased urine output. As the experiment progressed, the mice in this group experienced a significant drop in weight in the later stages, accompanied by a marked increase in water intake and urine output, worsening defecation difficulties, and obvious signs of ruffled hair, all reflecting poor health conditions. Figure 3 As shown, after supplementing with Pyrococcus lactis SWU-HX39, the trend of weight loss was effectively curbed, and at the end of the experiment, there was no statistically significant difference in weight between the HX39 group mice and the positive drug control group.

[0044] Changes in organ indices, such as Figure 4 As shown, compared with the control group, the kidney index of mice in the model group was significantly increased (P<0.0001), indicating that the kidneys may be congested or edematous, confirming that the modeling agent had significant toxic side effects on the mouse kidneys. However, after intervention with Pediococcus lactis, the kidney index of mice decreased significantly (P<0.05), indicating that Pediococcus lactis SWU-HX39 can effectively alleviate kidney damage induced by the modeling agent.

[0045] (2) Histological analysis Mouse kidneys were soaked in tissue fixative for 24 h, dehydrated stepwise with different concentrations of ethanol, cleared with xylene, and embedded in paraffin to form sections. The sections were dewaxed with xylene I and xylene II for 5 min each, then treated with an ethanol gradient (5 min anhydrous ethanol, 2 min 95% ethanol, 2 min 80% ethanol, 2 min 70% ethanol), followed by treatment with distilled water for 2 min. The dewaxed tissue sections were stained with hematoxylin for 20 min and then rinsed with tap water. Next, differentiation solution was applied for 30 s, and the tissue samples were soaked in water for 15 min. Then, eosin staining was applied for 30 s, followed by rinsing with tap water. After soaking in water for 5 min, the samples were dehydrated with an ethanol gradient, cleared with xylene, and sealed with neutral adhesive. Finally, they were observed and photographed using an optical microscope.

[0046] from Figure 5As can be seen from the morphological analysis of kidney tissue, the kidneys of the control group mice were dark red in color, with a moderate thickness of the cortex, and all internal structures remained normal. In contrast, the model group showed a large amount of uric acid crystal deposition in the renal interstitium and tubules, focal mild glomerular atrophy, and significant structural disorder of the glomeruli and tubules (black arrows); the tubular lumen was significantly dilated, the epithelial cells were significantly disordered, and the basement membrane remained intact (green arrows); the interstitial blood vessels were moderately dilated and congested (red arrows); and there was extensive lymphocyte infiltration (blue arrows). However, after administration of Pediococcus lactis SWU-HX39, the kidney disease symptoms were significantly alleviated, and the morphology of the mice was more similar to that of the control group. Compared with the normal control group, the kidneys of the positive control group were significantly lighter in color, and the kidney volume also showed a significant increasing trend, indicating that the kidneys also had a certain degree of lesions. This result not only verifies the protective effect of Pyotrophic Lactococcus SWU-HX39 on the kidneys of hyperuricemic mice, but also provides morphological evidence for its potential kidney health maintenance function.

[0047] (3) Determination of biochemical indicators (UA, CRE, and BUN): Serum UA (uric acid), CRE (creatinine), BUN (blood urea nitrogen), and XOD (xanthine oxidase) levels in serum and liver were measured using a commercially available test kit (Nanjing Jiancheng Institute, China). Measurements were performed according to the kit instructions. Eight samples from each group were selected for independent testing.

[0048] The typical hallmark of hyperuricemia is elevated serum uric acid levels, usually accompanied by a corresponding increase in creatinine and blood urea nitrogen levels. According to... Figure 6 Data showed that, compared with the control group, the serum uric acid, creatinine, and urea nitrogen concentrations in the model group mice were significantly increased (P < 0.0001), with the model group showing a 3.6-fold increase compared to the control group. This indicates the successful establishment of the hyperuricemia model. However, under the intervention of *Pediococcus lactis* HX39, the serum uric acid concentration in mice significantly decreased (P < 0.0001), with the HX39 group showing a 49.8% decrease in serum uric acid concentration compared to the model group. Simultaneously, the levels of creatinine (P < 0.001) and urea nitrogen (P < 0.01) also decreased significantly. These changes in biochemical indicators are consistent with previous observations of kidney sections and measurements of the kidney index. This effect may be attributed to the ability of strain SWU-HX39 to reduce the levels of precursor substances related to uric acid synthesis, thereby reducing uric acid production and alleviating the symptoms of hyperuricemia in mice.

[0049] Xanthine oxidase (XOD), a key enzyme in uric acid synthesis, exhibits increased activity in the liver when uric acid levels rise. Figure 6As shown, compared with the control group, the XOD activity in the liver and serum of mice in the model group was significantly increased (P < 0.01). However, after SWU-HX39 supplementation, the XOD activity in the liver and serum decreased, respectively (P < 0.05 and P < 0.01). These results indicate that the effect of Pyorrhizococcus lactis SWU-HX39 in alleviating hyperuricemia in mice is partly attributed to its ability to inhibit XOD activity, thereby reducing the synthesis of uric acid in the body.

[0050] (4) Determination of anti-inflammatory effect: Serum lipopolysaccharide (LPS) was measured by ELISA to evaluate typical inflammatory cytokines in the serum, in order to assess the damage (IL-1β, TNF-α and IL-6) caused by HUA-induced renal fibrosis in mice.

[0051] The results are as follows Figure 7 As shown, compared with the control group, the levels of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, IL-6, and LPS, were significantly increased in the serum of model group mice, indicating obvious abnormal cytokine levels. Intervention with *Pediococcus lactis* SWU-HX39 effectively reduced the levels of TNF-α, IL-1β, IL-6, and LPS in the serum of hyperuricemic mice, with reductions of 18.78%, 27.06%, 44.48%, and 30.47%, respectively. Compared with the positive control group, *Pediococcus lactis* SWU-HX39 showed comparable efficacy in regulating these cytokine levels, with no statistically significant difference between the two groups (P>0.05). This indicates that *Pediococcus lactis* SWU-HX39 has the ability to improve cytokine dysregulation in hyperuricemic mice and downregulate the levels of pro-inflammatory factors in the body, thereby achieving an anti-inflammatory effect.

[0052] (5) Intestinal flora analysis Mouse feces were thawed from a -80°C freezer. Total genomic DNA from the microbial community was extracted according to the EZNA® soil DNA kit (Omega Bio-tek, Norcross, GA, US) instructions. The quality of the extracted genomic DNA was assessed using 1% agarose gel electrophoresis, and DNA concentration and purity were determined using NanoDrop2000. Using the extracted DNA as a template, PCR amplification of the V3-V4 variable region of the 16S rRNA gene was performed using upstream primer 338F (5'-ACTCCTACGGGAGGCAGCAG-3') and downstream primer 806R (5'-GGACTACHVGGGTWTCTAAT-3') carrying the barcode sequence. The PCR products were recovered using 2% agarose gel electrophoresis, and the recovered products were quantified using a DNA gel purification kit. Then, NEXTFLEX was used... The purified PCR products were used to construct libraries using the Rapid DNA-Seq Kit, and sequencing was performed using the Illumina Nextseq 2000 platform. The raw sequencing sequences were then quality-controlled assembled using FASTP and FLASH. Based on default parameters, the optimized sequences after quality-controlled assembly were noise-reduced using the DADA2 plugin in the Qiime2 workflow. Based on the Sliva16S rRNA gene database, a series of statistical and visual analyses of ASVs were performed using the Naive Bayes classifier in Qiime2.

[0053] Patellar bacteria are key members of the human gut microbiota, crucial for maintaining health and deeply involved in multiple life processes such as immune enhancement, nutritional metabolism regulation, and antibacterial and antiviral defense. Studies have shown that tryptophanase has been found in Bacteroides, and the relative abundance of Bacteroides is closely related to tryptophanase gene levels. Tryptophan metabolites, as ligands, can activate aryl hydrocarbon receptor (AHR) signaling in various diseases, such as inflammation, chronic kidney disease, and cancer. Furthermore, tryptophan metabolism from gut microbiota has been shown to mediate kidney damage through AHR receptor signaling activation. Compared to the control group, the abundance of Bacteroides in the gut microbiota of model mice was significantly increased (p < 0.05), while the abundance of Firmicutes and Patellar bacteria was significantly lower. Patescibacteria The abundance of ) was significantly reduced (p < 0.05 and P < 0.001, respectively). However, intervention with P. SWU-HX39 effectively reversed these adverse changes.

[0054] At the genus level, a detailed analysis was conducted on the genera with significant differences among the groups. The results are as follows: Figure 8 The results showed that, compared with the control group, the model group significantly increased the relative abundance of *Bacteroides* (P < 0.01) and *Parabacteroides* (P < 0.05), and decreased the relative abundance of *Eubacterium* / *Eubacterium* and *Ruminococcus*. Intervention with *Pediococcus lactis* SWU-HX39 significantly decreased the relative abundance of *Bacteroides* (P < 0.05) and *Parabacteroides*, while increasing the relative abundance of *Eubacterium* / *Eubacterium* and *Ruminococcus*. *Ruminococcus* are major benign species inhabiting the cecum and colon, capable of degrading various fibers and polysaccharides and producing short-chain fatty acids (SCFAs). Studies have shown that the abundance of SCFA-producing bacteria (such as *Ruminococcus*) is significantly decreased in hyperuricemic mice, accompanied by kidney damage. These results indicate that intervention with *Pediococcus lactis* SWU-HX39 effectively modulates gut microbiota levels, corrects gut microbiota imbalance, and has the effectiveness and potential to improve hyperuricemia in mice.

[0055] (6) Determination of short-chain fatty acids (SCFAs): Take 50 mg of cecal contents into a 2 mL centrifuge tube, dissolve it with saturated NaCl until there are no obvious lumps, add H2SO4 to acidify, shake to mix, and then extract short-chain fatty acids with anhydrous diethyl ether. After extraction at 4℃ for 45 min, centrifuge at 12000 r / min for 15 min and collect the supernatant. Remove residual water from the supernatant with anhydrous sodium sulfate, centrifuge again, collect the upper ether phase, filter it through a nylon membrane, and add it to a brown sample bottle. Analyze the content of short-chain fatty acids (acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, valeric acid) by GC.

[0056] The metabolic benefits of SCFAs in humans are widely recognized, encompassing improvements in glucose homeostasis, enhanced glucose tolerance, and increased insulin sensitivity. This study focuses on the effects of *Pediococcus lactis* SWU-HX39 on the concentration of SCFAs in the cecal contents of hyperuricemic mice. Tests showed that, compared to the control group, the concentrations of acetic acid, propionic acid, butyric acid, and total acid in the model group mice were significantly reduced (P < 0.001). The levels of acetic acid, propionic acid, isobutyric acid, butyric acid, isovaleric acid, and valerate in the HX39 group mice were all increased to varying degrees compared to the model group, with the increases in acetic acid, propionic acid, and butyric acid being particularly significant. Specific experimental results are as follows: Figure 9 As shown, *Pediococcus lactis* SWU-HX39 significantly increased the levels of SCFAs in hyperuricemic mice, particularly in propionic acid concentration (P < 0.0001). This indicates that SCFA levels in hyperuricemic mice increased to varying degrees under SWU-HX39 intervention. SWU-HX39 increased the abundance of SCFA-producing bacteria, thereby raising SCFA levels in hyperuricemic mice, which in turn reduced uric acid levels and improved abnormal uric acid content. This result corroborates the gut microbiota structure analysis, further confirming the positive role of *Pediococcus lactis* SWU-HX39 in regulating gut microbiota and metabolic health in hyperuricemic mice. Although the SCFA levels in the positive control group were higher than those in the model group, they did not reach the levels of the HX39 group.

[0057] (7) Analysis of uric acid transporter gene expression in mouse kidneys The homeostasis of uric acid concentration in the body depends on the dynamic balance between its production and excretion. In human physiology, the kidneys are responsible for approximately two-thirds of uric acid excretion, and 90% of cases of hyperuricemia, a common metabolic disorder, are attributed to defects in the urate excretion mechanism. It has been reported that the ABCG2, SLC22A6, and SLC17A1 genes play important roles in uric acid excretion, while the GLUT9 gene is closely related to uric acid reabsorption.

[0058] like Figure 10As shown, compared with the control group, the expression levels of three uric acid excretion-related genes, ABCG2, SLC22A6, and SLC17A1, were significantly downregulated in the kidneys of model mice (P < 0.0001), while the expression level of the GLUT9 gene was significantly increased (P < 0.05). This indicates that their uric acid excretion capacity was severely inhibited and uric acid reabsorption was increased, further exacerbating the rise in serum uric acid levels. After intervention with *Pediococcus lactis* SWU-HX39, the expression levels of ABCG2, SLC22A6, and SLC17A1 genes were significantly upregulated, and the expression level of the GLUT9 gene was effectively reduced (P < 0.01). The overall trend was similar to that of the positive control group, but allopurinol showed a more significant effect in reducing GLUT9 expression. In conclusion, *Pediococcus lactis* SWU-HX39 exerted a positive regulatory effect on uric acid homeostasis in hyperuricemia model mice at the renal level by regulating the expression of genes related to uric acid excretion and reabsorption.

Claims

1. A strain of *Pediococcus lactis* SWU-HX39 with uric acid-lowering function, characterized in that: The classification name of the lactic acid cocci is *Pediococcus lactis* ( Pediococcus acidilactici SWU-HX39 is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 33055, on December 13, 2024, at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing.

2. The use of the *Pediococcus lactis* SWU-HX39 as described in claim 1 in the preparation of a drug for relieving hyperuricemia.

3. The application of the *Pediococcus lactis* SWU-HX39 as described in claim 1 in the preparation of foods that regulate intestinal flora.

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