Plant lactobacillus LPU3 and application thereof in relieving hyperuricemia

Abstract

The application belongs to the technical field of plant lactobacillus, and particularly relates to a plant lactobacillus LPU3 and application of the plant lactobacillus LPU3 in relieving hyperuricemia. The plant lactobacillus LPU3 has the functions of degrading uric acid in vitro, inhibiting xanthine oxidase in vitro, intervening hyperuricemia, inhibiting metabolic enzymes, improving kidney injury caused by hyperuricemia, improving kidney inflammation and oxidative stress caused by hyperuricemia, and improving intestinal flora disorder caused by hyperuricemia.

Description

Technical Field

[0001] This application belongs to the technical field of Lactobacillus plantarum, specifically relating to a strain of Lactobacillus plantarum LPU3 and its application in alleviating hyperuricemia. Background Technology

[0002] Lactiplantibacillus plantarum, a representative Gram-positive, facultative anaerobic probiotic strain, has become a research hotspot in the field of microbial functional development due to its excellent food-grade safety, intestinal colonization ability, and metabolic regulation potential. It is widely used in food fermentation, functional dietary supplements, and other applications. In recent years, with the increasing prominence of metabolic-related health problems, the application value of Lactiplantibacillus plantarum in the regulation of uric acid metabolism has been gradually explored. Related studies have shown that certain strains can help improve hyperuricemia-related metabolic disorders through pathways such as purine degradation, inhibition of key enzymes in uric acid production, or regulation of the intestinal flora.

[0003] In existing technologies, reported *Lactobacillus plantarum* strains with uric acid regulation potential include HZB-30, FS4722, and YDJ-03. Their functional mechanisms mainly focus on single-target intervention. For example, HZB-30 exerts xanthine oxidase (XOD) inhibitory activity by producing extracellular polysaccharides, FS4722 reduces uric acid production substrates through nucleoside hydrolases, and YDJ-03 focuses on optimizing renal uric acid transport function. However, these existing strains and related products still suffer from single functional targets, limited application forms, and reliance on live bacterial preparations, which present problems such as poor storage stability, weak gastric acid tolerance, and infection risks in special populations (such as immunocompromised individuals). Furthermore, systematic development targeting stabilized products such as dead *Lactobacillus plantarum* cells and metabiotics is insufficient.

[0004] Furthermore, the functional specificity of *Lactobacillus plantarum* is closely related to the genetic characteristics of the strain itself. Different strains exhibit significant differences in metabolite composition and enzyme activity expression, making it difficult to obtain a target strain with comprehensive functions and stable effects through general strain screening alone. Therefore, it is crucial to develop a *Lactobacillus plantarum* strain that can degrade uric acid and inhibit xanthine oxidase and adenosine deaminase in both live and inactivated forms. Summary of the Invention

[0005] This application provides a strain of Lactiplantibacillus plantarum LPU3, which is Lactiplantibacillus plantarum LPU3 with accession number CGMCC NO.37034. It has multiple functions such as uric acid degradation, metabolic enzyme inhibition, intestinal flora improvement and reduction of renal oxidative stress.

[0006] This application provides a uric acid degradation preparation comprising at least one or more of the following: dead cells, live cells, inactivated cells, postbiotics, and fermentation broth of *Lactobacillus plantarum* LPU3.

[0007] This application provides an inhibitor of xanthine oxidase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3.

[0008] This application provides an inhibitor of adenosine deaminase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3.

[0009] This application provides an inactivated bacterial cell of Lactiplantibacillus plantarum, wherein the Lactiplantibacillus plantarum is LPU3 with accession number CGMCCNO.37034, and the inactivated bacterial cell is a bacterial cell that has no replication ability after inactivation treatment.

[0010] This application provides a model strain containing inactivated Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

[0011] This application provides a control strain containing inactivated Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

[0012] This application provides an intervention strain containing inactivated Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

[0013] This application provides an auxiliary strain containing inactivated Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

[0014] This application provides applications of the aforementioned *Lactobacillus plantarum* LPU3, wherein the applications are selected from any one or more of the following: uric acid degradation preparations; xanthine oxidase inhibitors; adenosine deaminase inhibitors; preparation of products to assist in regulating uric acid metabolism; preparation of products to improve intestinal flora balance; preparation of products to reduce uric acid-induced renal oxidative stress; preparation of dried bodies; as a control strain for in vitro uric acid-lowering activity testing; as an experimental strain for in vitro uric acid system regulation; as a quality control strain for in vitro uric acid detection experiments; as a standard bacterial agent for in vitro uric acid-lowering activity testing; as an additive for in vitro purine / uric acid regulation in animal feed; as a standard strain or reagent for screening in vitro XOD enzyme inhibitory activity; as an experimental material for studying the XOD enzyme enzymatic reaction mechanism. Materials; used as performance verification reagents for XOD enzyme activity assay kits; used as in vitro purification aids for processing high-purine substrate foods; used as model strains for studying the regulatory mechanisms of XOD and ADA enzymes in vivo; used as control strains for screening the inhibitory activity of XOD and ADA enzymes in vivo; used as research strains for experiments on the metabolic regulation of XOD and ADA enzymes in animals; used as functional food ingredients with in vivo XOD and ADA enzyme inhibitory properties; used as interventional strains for the metabolic regulation of XOD and ADA enzymes in experimental animals; used as auxiliary strains for studying the correlation between intestinal microecology and XOD and ADA metabolism in experimental animals; used as raw materials for extracting active ingredients for the inhibition of XOD and ADA enzymes in vivo; used as materials for studying the physiological protective mechanisms of kidney tissue in experimental animals. This strain serves as a model strain for research; a control strain for screening the physiological protective activity of kidneys in experimental animals; an intervention strain for regulating the physiological state of kidney tissues in experimental animals; an auxiliary strain for studying the physiological correlation between the gut and kidney axis in experimental animals; a raw material for extracting physiological protective active ingredients for kidneys in experimental animals; a model strain for studying the physiological regulation mechanism of Firmicutes / Bacteroidetes in the gut of experimental animals; a control strain for screening the abundance regulation activity of Firmicutes / Bacteroidetes in the gut of experimental animals; an experimental strain for studying the correlation between gut phylum structure and host physiology; an intervention strain for regulating the structure and physiology of Firmicutes and Bacteroidetes in the gut of experimental animals; and an auxiliary strain for constructing a model of Firmicutes / Bacteroidetes imbalance in the gut of experimental animals. As an extractable raw material for regulating active components of Firmicutes / Bacteroides in the gut of laboratory animals; as an industrially produced strain of functional microecological biological raw material; as a feed additive for livestock / poultry / aquaculture; as a model strain for studying the abundance regulation mechanism of Bilopathobacterium, Bacteroides, Myxospira, and Colidellella in the gut of laboratory animals; as a control strain for screening the abundance inhibition activity of Bilopathobacterium, Bacteroides, Myxospira, and Colidellella in the gut of laboratory animals; as an experimental strain for studying the correlation between Bilopathobacterium, Bacteroides, Myxospira, and Colidellella and the host microecological balance; as a food-grade functional ingredient with the characteristics of regulating the abundance of Bilopathobacterium, Bacteroides, Myxospira, and Colidellella in the gut of laboratory animals.Fermentation strains used in functional fermented foods. Attached Figure Description

[0015] Figure 1 The graph shows the degradation rates of uric acid, inosine, and guanosine in Lactobacillus plantarum LPU3 provided in the test example.

[0016] Figure 2 The graph shows the growth of live and inactivated Lactobacillus plantarum cells (LPU3) and uric acid degradation rate on MRS provided in the test example.

[0017] Figure 3 This is a graph showing the in vitro XOD inhibition rate of live and inactivated Lactobacillus plantarum cells (LPU3) and LPU3_P provided in the test examples.

[0018] Figure 4 The graphs provided in the test case show the changes in body weight (A) and uric acid levels in each group of mice.

[0019] Figure 5 The graph shows the activity values ​​of adenosine deaminase and xanthine oxidase in the serum of mice in each group provided in the test case.

[0020] Figure 6 These are the kidney index diagrams and actual kidney images of each group of mice provided in the test cases.

[0021] Figure 7 The graph shows the levels of creatinine and urea nitrogen in the serum of mice in each group, as provided in the test case.

[0022] Figure 8 These are morphological images of mouse kidney tissue sections provided in the test cases.

[0023] Figure 9 The graph shows the levels of inflammatory factors (IL-1β, IL-18, TNF-α) and malondialdehyde (MDA) in the kidneys of mice in each group, as provided in the test case.

[0024] Figure 10 The image shows the OUT Venn diagram of the gut microbiota of each group of mice provided in the test case.

[0025] Figure 11 The test cases provide α-diversity index diagrams of the gut microbiota communities of mice in each group (Chao index, Shannon index, Simpson index).

[0026] Figure 12 The images show the PCOA (Proteinized Occult Acid) diagrams of the gut microbiota communities in each group of mice provided in the test cases.

[0027] Figure 13The test examples provide comparison charts of the GMHI and MDI indices between every two groups in the NC, MC, LPU3, LPU3_P, and ADC groups. For each sub-plot, a significant difference between any two groups is defined as p < 0.01.

[0028] Figure 14 This is a graph showing the phylum abundance of the gut microbiota in each group of mice provided in the test case.

[0029] Figure 15 This is a bar chart showing the differences in gut microbiota genera among the groups of mice provided in the test cases.

[0030] In the above figure, different letters represent statistically significant differences between groups (p < 0.05). Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. Reagents not specifically described in detail herein are all conventional reagents and are commercially available; methods not specifically described in detail are all conventional experimental methods and can be learned from the prior art.

[0032] In view of the lack of systematic development of stable products such as dead bacterial cells and metabiotics of *Lactobacillus plantarum*, this application provides a strain of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034, as well as its inactivated bacterial cells, dried bacterial cells, uric acid degradation agents, xanthine oxidase inhibitors, adenosine deaminase inhibitors, compositions, and applications, which realize multiple functions such as uric acid degradation, metabolic enzyme inhibition, intestinal flora improvement, and reduction of renal oxidative stress.

[0033] In one screening process, target strains were isolated from adult fecal samples. The samples were serially diluted with sterile physiological saline and spread onto MRS solid medium, then anaerobically cultured at 37°C for 48 hours. Morphologically typical single colonies (round, milky white, with neat edges) were picked and Gram-stained for microscopic examination (Gram-positive, non-spore-forming, rod-shaped) to preliminarily screen for candidate strains of *Lactobacillus plantarum*. The candidate strains were inoculated into MRS liquid medium containing uric acid (600 mmol / L) and anaerobically cultured at 37°C for 24 hours. The uric acid degradation rate was detected using a uric acid assay kit, and strains with a degradation rate ≥30% were screened. Further, XOD inhibition activity was detected using an in vitro enzyme activity system, and strains with an inhibition rate ≥25% were screened, ultimately obtaining the target strain LPU3. Strain LPU3 was passaged three times, and the above functional verification was repeated to confirm that its uric acid degradation and XOD inhibition activities were stable (coefficient of variation ≤5%).

[0034] In one identification process, strain LPU3 appeared as round, milky-white colonies on MRS medium, 1-2 mm in diameter, with neat edges and a smooth surface; Gram-positive, rod-shaped, non-spore-forming, and arranged singly or in pairs. Genomic DNA was extracted from the strain, and its 16S rRNA gene was amplified by PCR. After sequencing, the amplified product was compared with the GenBank database. The results showed that the strain had ≥99.8% homology with the type strain of *Lactiplantibacillus plantarum*. Based on morphological and physiological-biochemical characteristics, it was identified as *Lactiplantibacillus plantarum*, with the taxonomic name *Lactiplantibacillus plantarum* LPU3. It has been deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC NO.37034, deposit date December 11, 2025, and deposit address No. 3, No. 1 Beichen West Road, Chaoyang District, Beijing. This strain has been identified as a Gram-positive bacterium, non-spore-forming, facultatively anaerobic, and has good food-grade safety.

[0035] The embodiment provides a uric acid degradation formulation comprising at least one or more of the following: dead cells, live cells, inactivated cells, post-biotics, and fermentation broth of *Lactobacillus plantarum* LPU3. This formulation achieves uric acid degradation, particularly in vitro, through different cell forms.

[0036] The embodiment provides an inhibitor of xanthine oxidase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3.

[0037] The embodiment provides an inhibitor of adenosine deaminase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3.

[0038] In some embodiments, the Lactobacillus plantarum LPU3 strain according to this application may be an isolated bacterial strain or a pure culture colony.

[0039] In some of the formulations provided in the embodiments, the concentration of at least one or more of the dead bacterial cells, live bacterial cells, and inactivated bacterial cells is 10. 2 Up to 10 17 Within the range of colony-forming units per gram or per milliliter (CFU / g or CFU / mL), for example, in 10 5 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 10 6 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 107 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 10 8 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 10 9 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 10 10 -10 17 Within the range of CFU / g or CFU / mL, for example, in the range of 10 11 -10 16 Within the range of CFU / g or CFU / mL, for example, in the range of 10 12 -10 16 Within the range of CFU / g or CFU / mL, for example, in the range of 10 13 -10 16 Within the range of CFU / g or CFU / mL, for example, in the range of 10 7 -10 16 Within the range of CFU / g or CFU / mL, for example, in the range of 10 8 -10 15 Within the range of CFU / g or CFU / mL, for example, in the range of 10 9 -10 15 Within the range of CFU / g or CFU / mL, for example, in the range of 10 10 -10 15 Within the range of CFU / g or CFU / mL, for example, in the range of 10 11 -10 15 Within the range of CFU / g or CFU / mL, for example, in the range of 10 12 -10 15 Within the range of CFU / g or CFU / mL.

[0040] In the context of this application, *Lactobacillus plantarum* LPU3 as defined herein can be provided in the composition according to this application in the form of at least one or more of dead, live, and inactivated bacterial cells. Live bacterial cells refer to live *Lactobacillus plantarum* bacteria with intact cell structure, capable of normal metabolism and reproduction, for example, cultured in a culture medium (such as MRS medium), centrifuged, washed to retain viability, and usually preserved in lyophilized form (such as lyophilized bacterial powder). For example, live bacterial cells refer to the bacterial solid obtained by collecting the strain after fermentation in MRS medium by centrifugation and washing with physiological saline. Dead bacterial cells refer to bacterial cells that have died naturally or lost their activity through physical / chemical treatment (such as high temperature, ultraviolet light), and whose cell structure may be intact or partially destroyed. For example, dead bacterial cells are obtained by freeze-drying live bacterial cells, grinding and crushing them, and passing them through a 200-mesh sieve to obtain bacterial fragment powder (protein content ≥30%). Inactivated bacterial cells specifically refer to bacterial cells that have been killed by controlled methods (such as heat inactivation, formaldehyde treatment, high pressure treatment) but retain their cell surface structures (such as cell wall, capsule). Inactivated bacteria emphasize "structural preservation," while dead bacteria may suffer structural damage due to processing methods. For example, inactivated bacteria are produced by sterilizing live bacteria with moist heat at 60°C for 30 minutes (or treating with 0.5% formaldehyde solution for 1 hour) to ensure no live bacteria are present (live bacteria count <10 CFU / mL using plate counting method), thus preserving the bacterial structure and metabolites.

[0041] In some of the formulations provided in the embodiments, Lactobacillus plantarum LPU3 may be used as an active ingredient in a mixture of at least one or more of dead, live and inactivated bacterial cells, and the active ingredient accounts for 0.0001% (w / w) to 99% (w / w) of the total mass of the above-mentioned uric acid degradation formulation, xanthine oxidase inhibitor and adenosine deaminase inhibitor.

[0042] The embodiment also provides an inactivated bacterial cell of Lactiplantibacillus plantarum, wherein the Lactiplantibacillus plantarum is LPU3 with accession number CGMCC NO.37034, and the inactivated bacterial cell is a bacterial cell that has no replication ability after inactivation treatment.

[0043] Specifically, the preparation process of the inactivated bacterial cells includes: subculturing *Lactobacillus plantarum* LPU3 twice, inoculating it into 10 mL of MRS medium at an inoculum size of 3% (V / V), and culturing for 16 h to obtain the fermentation broth containing live bacterial cells. Incubating this fermentation broth in a 70°C water bath for 30 min yields the fermentation broth containing inactivated bacterial cells. Figure 2As shown, when the fermentation broth containing dead bacteria was inoculated onto MRS medium, no colony growth was observed, indicating that *Lactobacillus plantarum* LPU3 had been inactivated after a 30-minute water bath at 70°C. In some embodiments, the fermentation broth containing inactivated bacteria was centrifuged at 8000 rpm for 15 minutes, the bacterial precipitate was collected, and washed twice with sterile physiological saline to obtain a concentrated inactivated bacterial broth.

[0044] In some embodiments, the aforementioned uric acid degradation agents, xanthine oxidase inhibitors, and adenosine deaminase inhibitors also include excipients such as stabilizers, carriers, and dispersants. The stabilizers are selected from trehalose, skim milk powder, or xanthan gum; the carriers are selected from maltodextrin, lactose, or corn starch; and the dispersants are selected from polyethylene glycol or Tween 80.

[0045] In some embodiments, the uric acid degradation agent, the xanthine oxidase inhibitor, and the adenosine deaminase inhibitor are all in the form of powder, tablet, ointment, emulsion, oil, suspension, lotion, gel, paste, foam, dairy product, gel, mist, or spray, respectively.

[0046] In some embodiments, the aforementioned uric acid degradation preparation, xanthine oxidase inhibitor, and adenosine deaminase inhibitor are all powders containing live or inactivated Lactobacillus plantarum LPU3 cells. Specifically, they contain 1×10¹¹ CFU / g of Lactobacillus plantarum LPU3 live cell concentrate, maltodextrin, and trehalose. For example, the aforementioned uric acid degradation preparation, xanthine oxidase inhibitor, and adenosine deaminase inhibitor contain 10g of 1×10¹¹ CFU / g of Lactobacillus plantarum LPU3 live or inactivated cell concentrate, 80g of maltodextrin, and 10g of trehalose. The Lactobacillus plantarum LPU3 live cell concentrate can be mixed evenly with maltodextrin and trehalose, and then aseptically packaged (1g / bag) to obtain a powder formulation.

[0047] In some embodiments, the uric acid degradation agent, xanthine oxidase inhibitor, and adenosine deaminase inhibitor described above are liquid formulations containing dead L. plantarum LPU3 cells. Specifically, they contain 1×10¹¹ CFU / g of dead L. plantarum LPU3 cells, xanthan gum, and sterile physiological saline. For example, the uric acid degradation agent, xanthine oxidase inhibitor, and adenosine deaminase inhibitor described above contain 5g of 1×10¹¹ CFU / g L. plantarum LPU3 cell concentrate, 0.5g of xanthan gum, and 94.5mL of sterile physiological saline. The dead cells and xanthan gum can be added to sterile physiological saline, stirred to dissolve, and homogenized at 10000 rpm for 10 min to obtain the liquid formulation.

[0048] In this article, "metapiogenics" refers to the collective term for physiologically active bacterial components and metabolites produced by probiotics (such as *Lactobacillus plantarum* in this article) after specific processing. Its core characteristic is that it can exert its functions without relying on the live state of the bacteria. Specifically, "metapiogenics" can include at least one of the following: inactivated bacterial cells, solutions containing inactivated bacterial cells, fermentation broth containing inactivated bacterial cells, or inactivated fermentation solutions; or the "beneficial legacy" left after the death of probiotics or their metabolites.

[0049] In some embodiments, the aforementioned uric acid-degrading agents, xanthine oxidase inhibitors, and adenosine deaminase inhibitors may be provided in solid, liquid, viscous, emulsion, or dry form. The formulations provided in some embodiments are preferably formulated as pastes, soft gelatin capsules, hard gelatin capsules, powders, talc, granules, beads, lozenges, effervescent tablets, rhomboid lozenges, oral tablets, chewable tablets, sublingual tablets, oils, liquids, solutions, tinctures, emulsions, fruit juices, concentrates, syrups, sprays, mists, drinking ampoules, gels, tablets, or coated pills.

[0050] Some of the embodiments provide formulations that are powders, tablets, ointments, emulsions, oils, suspensions, lotions, gels, pastes, foams, dairy products, gels, mists, sprays, or fermented preparations.

[0051] In some embodiments, the metabiotic can be a solution obtained by passing the fermentation broth of Lactobacillus plantarum LPU3 through a 70°C water bath for 30 minutes.

[0052] In some embodiments, the aforementioned uric acid degradation formulation, xanthine oxidase inhibitor, and adenosine deaminase inhibitor all contain post-generics of *Lactobacillus plantarum* LPU3 and excipients. These excipients include diluents, preservatives, and thickeners. The diluent is sterile saline or maltodextrin. The preservative is sodium benzoate or potassium sorbate. The thickener is sodium carboxymethyl cellulose or gelatin.

[0053] In some embodiments, the uric acid degradation agent, the xanthine oxidase inhibitor, and the adenosine deaminase inhibitor described above are liquid formulations containing *Lactobacillus plantarum* LPU3 postbiotic. For example, *Lactobacillus plantarum* is fermented to a viable count of not less than 1 × 10⁻⁶. 10 CFU / mL, incubate at 70℃ for 30 min, take 100 mL of the supernatant, add 0.1 g of potassium sorbate, stir to dissolve, sterilize, and dispense into 10 mL / bottles to obtain the liquid preparation.

[0054] In some embodiments, the uric acid degradation agent, xanthine oxidase inhibitor, and adenosine deaminase inhibitor described above are powders containing *Lactobacillus plantarum* LPU3 post-biotic. For example, *Lactobacillus plantarum* is fermented until the viable count is not less than 1 × 10⁻⁶.10 After being heated to CFU / mL in a water bath at 70℃ for 30 minutes, the product was freeze-dried to obtain a powder. 1g of the powder was mixed evenly with 99g of maltodextrin and aseptically packaged (0.5g / bag) to obtain a powder formulation (post-biotic content 10μg / bag).

[0055] In some embodiments, the uric acid degradation agent, the xanthine oxidase inhibitor, and the adenosine deaminase inhibitor described above are gel formulations containing *Lactobacillus plantarum* LPU3 post-biotic. For example, *Lactobacillus plantarum* is fermented until the viable cell count is not less than 1 × 10⁻⁶. 10 After mixing CFU / mL with 2g sodium carboxymethyl cellulose, 5g glycerol, and 73mL sterile water in a 70℃ water bath for 30min, and then sterilizing at 60℃ for 30min, the gel formulation is obtained after cooling.

[0056] The embodiment also provides a dried body, which is prepared by freeze-drying the aforementioned Lactobacillus plantarum LPU3. The dried body has a water content of ≤5% and a viable bacteria retention rate of ≥85% after rehydration.

[0057] In some embodiments, the preparation process of the dried body includes:

[0058] The fermentation broth of *Lactobacillus plantarum* LPU3 (anaerobic fermentation at 37℃ for 24 hours, viable cell count ≥1×10¹) was used to ferment the bacteria. 0 Centrifuge at 8000 r / min for 15 min (CFU / mL), collect the bacterial pellet, wash twice with sterile physiological saline, and resuspend in a solution containing a protectant (bacterial concentration 1×10¹¹ CFU / mL); wherein the protectant is at least one of skim milk powder, trehalose, sucrose, and mannitol; for example, add 10%~15% skim milk powder as protectant, or 5%~10% trehalose as protectant, or 8%~12% sucrose as protectant, or a total addition of 15%~20% skim milk powder and trehalose in a 2:1 mass ratio as protectant, or a total addition of 12%~18% sucrose and mannitol in a 3:1 mass ratio as protectant;

[0059] Aliquot the resuspension into lyophilization bottles and pre-freeze at -40℃ to -60℃ for 2 to 4 hours to ensure that the sample is completely frozen.

[0060] Vacuum degree 10~30Pa, temperature -30℃~-20℃, dry for 8~12h to remove free water from the sample;

[0061] Vacuum degree 5~10Pa, temperature 20℃~30℃, dry for 2~4h to remove bound water from the sample;

[0062] After drying, seal and store with a moisture content of ≤5%. After rehydration, the viable bacteria retention rate is ≥85%.

[0063] The resulting dried product is a loose white powder that is easily rehydrated (completely dissolved within 30 seconds after adding sterile saline); after sealing, it can be stored at -20℃ to 4℃ with a shelf life of 6 to 12 months (longer shelf life when stored at -20℃); it can be directly packaged as freeze-dried bacterial powder (end product) or used as an intermediate product for the preparation of bacterial agents and compositions.

[0064] The dried form provided in these embodiments, as a stabilized form of the strain, retains the dual functions of antibacterial and targeted adhesion copolymerization, facilitating storage, transportation, and subsequent processing. It exhibits high stability; a moisture content ≤5% significantly reduces the metabolic activity of the strain, extending shelf life (6 months at 4°C, with a viable count still ≥1×10⁻⁶). 9 (CFU / g) It is easy to process, the dried body is in powder form, and can be directly mixed with excipients to prepare various formulations such as powders, granules, and capsules. The processing technology is simple. The transportation cost is low. The dried body is small in volume and light in weight, and does not require cold chain transportation (it can withstand short-term room temperature transportation), thus reducing logistics costs.

[0065] Furthermore, these dried products solve the technical problems of short storage period and high transportation cost of live bacterial preparations, improving the market circulation of the products; the live bacterial count retention rate after rehydration is ≥85%, ensuring that the functional activity of the strains is not affected by the drying process; they can be used as intermediate or end products, flexibly adapting to different industrialization needs, such as being sold directly as freeze-dried bacterial powder, or used to prepare compound preparations.

[0066] The embodiment also provides a composition characterized in that it comprises at least one of the following: *Lactobacillus plantarum* LPU3, the uric acid degradation agent, the xanthine oxidase inhibitor, the adenosine deaminase inhibitor, the dead bacterial cell, and the dried cell.

[0067] This application provides applications of the aforementioned *Lactobacillus plantarum* LPU3, including: uric acid degradation agents; inhibitors of xanthine oxidase; inhibitors of adenosine deaminase; preparation of products that assist in regulating uric acid metabolism; preparation of products that improve intestinal flora balance; preparation of products that alleviate renal oxidative stress induced by hyperuricemia; and preparation of at least one of the following: dried body.

[0068] The following detailed explanation of the functions achievable by the implementation scheme of this application, with reference to test examples, does not constitute a limitation on the implementation method of this application.

[0069] MRS medium: peptone 10 g / L, beef extract 5 g / L, yeast extract 5 g / L, glucose 20 g / L, anhydrous sodium acetate 5 g / L, diammonium hydrogen citrate 2 g / L, Tween 80 1 g / L, K₂HPO₄ 2 g / L, MgSO₄ 0.2 g / L, MnSO₄ 0.05 g / L, pH=6.20±0.20, sterilized at 121℃ for 20 min.

[0070] Male C57BL / 6J mice were purchased from Spifort (Beijing) Biotechnology Co., Ltd. and housed in the animal facility of Hubei Provincial Center for Disease Control and Prevention. Animal experiment ethics number: Safety Evaluation Center Animal (Fu) No. 202510315.

[0071] Test Example 1: In vitro degradation of uric acid and nucleosides by Lactobacillus plantarum LPU3

[0072] The strain was passaged twice and inoculated into 30 mL of MRS medium at a 3% (V / V) inoculum, and cultured for 16 h. 10 mL of the bacterial culture was collected into a centrifuge tube, centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the bacterial pellet was washed with 5 mL of PBS twice. The pellet was resuspended in 900 μL of 0.6 mmol / L uric acid solution and incubated at 37 °C for 60 min. 100 μL of 0.1 mol / L perchloric acid was added, the mixture was shaken, and centrifuged at 4000 x g for 10 min. The supernatant was collected and filtered through a 0.22 μm filter into a liquid chromatography vial. The mobile phase was potassium dihydrogen phosphate:methanol 96:4, the UV wavelength was 254 nm, the column temperature was 25 °C, and isocratic elution was performed for 20 min. The results were quantitatively determined using the external standard method. Following the same method, the bacterial culture was cultured and centrifuged, and the bacterial pellet was resuspended in 0.6 mmol / L inosine and guanosine solutions, respectively, to determine the bacterial degradation capacity for inosine and guanosine.

[0073] The results are as follows Figure 1 As shown, the uric acid degradation rate of LPU3 was 53.51%±1.11, the inosine degradation rate was 100%±0.00, and the guanosine degradation rate was 100%±0.00.

[0074] Test Example 2: In vitro uric acid degradation capacity test of inactivated Lactobacillus plantarum cells (LPU3_P)

[0075] The strain was passaged twice and inoculated into 10 mL of MRS medium at a 3% (v / v) inoculum, and cultured for 16 h. The bacterial suspension was divided into two equal portions. One portion was incubated at 70°C for 30 min and denoted as LPU3_P. The other portion was left untreated and denoted as LPU3. After treatment, the two portions of bacterial suspension were streaked onto two separate culture media using an inoculation loop and incubated at 37°C for 24 h.

[0076] The strain was passaged twice and inoculated into 10 mL of MRS medium at a 3% (v / v) inoculum, and cultured for 16 h. 10 mL of bacterial culture was collected into a centrifuge tube, centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the bacterial pellet was washed with 5 mL PBS twice. The pellet was resuspended in 5 mL PBS and incubated at 70 °C for 30 min. After the water bath, the pellet was centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the pellet was resuspended in 900 μL of 0.6 mmol / L uric acid solution and incubated at 37 °C for 60 min. 100 μL of 0.1 mol / L perchloric acid was added, the mixture was shaken to mix, and centrifuged at 4000 x g for 10 min. The supernatant was collected and filtered through a 0.22 μm filter into a liquid chromatography vial. The mobile phase was potassium dihydrogen phosphate:methanol 96:4, the UV wavelength was 254 nm, the column temperature was 25 °C, and isocratic elution was performed for 20 min. The results were quantitatively determined using the external standard method.

[0077] like Figure 2 As shown, no colony growth was observed when LPU3_P was inoculated onto MRS medium, indicating that *Lactobacillus plantarum* LPU3 was dead after a 30-minute water bath at 70°C. The uric acid degradation capacity of LPU3_P was determined, and its uric acid degradation rate was 34.45% ± 2.59%.

[0078] Based on this, the embodiments of this application also provide a model strain for studying the in vitro uric acid metabolism regulation mechanism. Its inactivated bacterial cells are used in the laboratory to conduct basic research on the in vitro interaction between microorganisms (inactivated form) and uric acid, and the in vitro uric acid-lowering mechanism of microorganisms, providing functionally defined experimental materials for microecological research on in vitro uric acid regulation. This model strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0079] Based on this, the embodiments of this application also provide a control strain for in vitro uric acid-lowering activity detection. Its inactivated bacterial cells are used to construct a high-throughput screening model for in vitro uric acid degradation / adsorption activity, assisting in the activity screening and verification of strains, natural products, and food ingredients with in vitro uric acid-lowering potential in the food and microbiology fields, serving as an experimental control benchmark. This control strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0080] Based on this, the embodiments of this application also provide an experimental strain for regulating an in vitro uric acid system. The inactivated bacterial cells are used in laboratory studies simulating the in vitro uric acid environment to investigate the effects of inactivated probiotics on the concentration and speciation of uric acid in vitro. This is for in vitro experimental research only and does not involve in vivo application. This experimental strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0081] Based on this, the embodiments of this application also provide a quality control strain for in vitro uric acid detection experiments. The inactivated bacterial cells are used for performance verification and quality control of in vitro uric acid detection kits and methods, improving the accuracy and stability of in vitro uric acid detection experiments, and are only used as reagents. This quality control strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0082] Based on this, the embodiments of this application also provide a standard bacterial agent for in vitro uric acid-lowering activity experiments. The inactivated bacterial cells are quantitatively prepared into a standardized bacterial agent for use as a positive control in laboratory in vitro uric acid-lowering activity experiments, providing a unified activity reference standard for similar experiments. This standard bacterial agent contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034. The formulation and excipients of this standard bacterial agent are the same as those of the uric acid degradation preparations provided in the above embodiments, and will not be repeated here.

[0083] Based on this, this application also provides an additive for regulating purine / uric acid in animal feed. Its inactivated bacterial cells are added to the in vitro processing stage of high-purine animal feed to help reduce the concentration of uric acid-related precursors / uric acid in the in vitro feed system, optimizing the nutritional composition of the feed. This additive is only used as a functional additive in in vitro feed processing and is not directly added to the animal body, focusing on feed quality optimization. This additive contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0084] Test Example 3: In vitro xanthine oxidase inhibition ability test of live and inactivated Lactobacillus plantarum cells (LPU3) and LPU3_P

[0085] The strain was passaged twice and inoculated into MRS medium at a 3% (v / v) inoculum, and cultured for 16 h. The bacterial suspension was divided into two equal portions, centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the bacterial pellet was washed with 2 mL PBS. This process was repeated twice. One portion of the bacterial pellet was resuspended in 2 mL PBS, vortexed, and incubated at 70 °C for 30 min, labeled LPU3_P. The other portion was left untreated, directly resuspended in 2 mL PBS, vortexed, and labeled LPU3 for later use. The enzymatic reaction system was prepared by adding 560 μL PBS, 20 μL XOD solution (0.05 U / mL), and 40 μL of the sample to be tested. After mixing, the mixture was incubated at 37 °C for 10 min, and then 200.0 μL xanthine solution (2 mmol / L) was added to initiate the reaction. The absorbance of the reaction solution at 295 nm was measured using a UV spectrophotometer, recorded every minute for 6 min. Plot the reaction time on the x-axis and absorbance on the y-axis to determine the slope of the curve, i.e., the reaction rate As. Use the same volume of PBS as a blank control; the slope of its curve represents the enzyme reaction rate Ac. Calculate the inhibition rate of the strain on XOD activity. The calculation formula is as follows:

[0086] XOD inhibition rate (%) = (1 - As / Ac) × 100%

[0087] In the formula: As is the reaction rate of the sample to be tested; Ac is the reaction rate of the control group.

[0088] like Figure 3 As shown, the XOD inhibition rate of LPU3 was 97.83% ± 0.35, and the XOD inhibition rate of LPU3_P was 95.39% ± 1.15. That is, the live cells of the LPU3 strain provided in this application have XOD inhibitory effects, and its inactivated cells also have XOD inhibitory effects.

[0089] Based on this, embodiments of this application also provide standard strains or reagents for screening in vitro XOD enzyme inhibitory activity: using inactivated *Lactobacillus plantarum* cells as a positive control, a high-throughput screening model for in vitro XOD enzyme inhibitory activity is constructed for screening other natural products, food ingredients, or microbial strains with potential enzyme inhibitory activity. The standard strain or reagent contains inactivated *Lactobacillus plantarum* LPU3 cells with accession number CGMCC NO.37034.

[0090] Based on this, the embodiments of this application also provide experimental materials for studying the XOD enzyme enzymatic reaction mechanism, which are used in the laboratory to conduct basic research on the interaction mechanism between inactivated bacterial cells and XOD enzyme in in vitro enzymatic reaction systems, and to explore the influence of microbial cells on enzyme activity. The experimental materials include inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0091] Based on this, this application also provides a performance verification reagent for XOD enzyme activity detection kits, used to verify the accuracy and sensitivity of in vitro XOD enzyme activity detection kits, test strips, and other products, ensuring quality control of in vitro detection experiments. This performance verification reagent contains inactivated Lactobacillus plantarum LPU3 cells with accession number CGMCC NO.37034.

[0092] Based on this, embodiments of this application also provide an in vitro purification aid for processing high-purine substrate foods. Utilizing its in vitro inhibitory properties against XOD enzymes, it is used as an additive in the in vitro processing stages (such as soaking, washing, and pretreatment) of high-purine raw materials like animal organs and seafood to optimize the enzymatic environment of the food processing system, without involving any in vivo effects after human ingestion. This in vitro purification aid contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0093] Test Example 4: Interventional effect of Lactobacillus plantarum LPU3 and its inactivated cells (LPU3_P) on hyperuricemia

[0094] Model establishment: Six- to eight-week-old male C57BL / 6J mice (18-20g) were housed in an environment with a room temperature of 25°C ± 2°C, humidity of 50% ± 5%, and a 12-hour light-dark cycle. After a 7-day acclimatization period, the mice were randomly divided into four groups (n=8 / group): NC, MC, LPU3, LPU3_P, and ADC. Hyperuricemia was induced in the MC, LPU3, LPU3_P, and ADC groups. The model was established by suspending potassium oxonate in 0.5% sodium carboxymethyl cellulose solution and adenine in physiological saline. Mice were administered 0.2 mL of adenine (50 mg / kg) by gavage and 0.2 mL of potassium oxonate solution (250 mg / kg) by intraperitoneal injection daily. Mice in the NC group were administered the same volume of physiological saline by gavage and the same volume of 0.5% sodium carboxymethyl cellulose solution by intraperitoneal injection. Mice in the LPU3 and LPU3_P groups were treated with adenine and potassium oxonate for 4 hours, and then administered 0.2 mL of physiological saline-live bacteria solution (containing Lactobacillus plantarum LPU3 10) by gavage. 9 CFU / animal) and physiological saline-inactivated bacterial solution (inactivated Lactobacillus plantarum LPU310 at 70℃ for 30 min) 9 Mice in the ADC group were given 0.2 mL of saline containing 5 mg / kg allopurinol, while mice in the NC and MC groups were given the same volume of saline. Mice were weighed every 3 days, and orbital blood was collected every 7 days to measure uric acid levels. The experiment lasted for 21 days. After 21 days, mice were weighed and euthanized.

[0095] like Figure 4As shown in Figure A, the body weight of mice in the MC and ADC groups gradually decreased, showing a significant difference compared to the NC group. After intervention with *Lactobacillus plantarum* LPU3 and inactivated bacterial solution LPU3_P, the body weight of mice gradually recovered, significantly increasing compared to the MC group. This indicates that *Lactobacillus plantarum* LPU3 and its inactivated bacterial solution can effectively improve the health status of mice with hyperuricemia.

[0096] Test Example 5: The inhibitory effect of Lactobacillus plantarum LPU3 and its inactivated cells (LPU3_P) on metabolic enzymes and the effect of reducing uric acid.

[0097] After the in vivo experiment, blood was collected from each group of mice for the detection of adenosine deaminase (ADA), xanthine oxidase (XOD), and uric acid (UA). The results are as follows: Figure 5 and Figure 4 As shown in B, ADA and XOD are important metabolic enzymes in the uric acid production pathway. ADA deamination converts adenosine to inosine. Inosine is further converted to hypoxanthine. XOD catalyzes the conversion of hypoxanthine to xanthine, which is then further catalyzed to uric acid. When the activities of ADA and XOD increase, uric acid production increases; when the activities of ADA and XOD decrease, uric acid production decreases.

[0098] like Figure 5 As shown, the activities of ADA and XOD in the MC group were significantly higher than those in the NC group. However, after intervention with LPU3 and LPU3_P, the activities of ADA and XOD were significantly lower than those in the MC group. That is, the live cells of the LPU3 strain provided in this application have inhibitory effects on XOD and ADA after in vivo intervention, and its inactivated cells also have inhibitory effects on XOD and ADA after in vivo intervention.

[0099] like Figure 4 As shown in Figure B, on day 7 of the experiment, the serum uric acid level in the MC group mice was significantly higher than that in the NC group, and remained stable thereafter. However, after intervention with LPU3 and LPU3_P, the serum uric acid level in mice was significantly reduced on day 14, and thereafter, the serum uric acid level remained significantly lower than that in the MC group. That is, the live LPU3 strain provided in this application has a hematuria-reducing effect after in vivo intervention, and its inactivated strain also has a hematuria-reducing effect after in vivo intervention.

[0100] Based on this, this application also provides a model strain for studying the regulatory mechanisms of XOD and ADA enzymes in vivo. Its inactivated bacterial cells are used in the laboratory to conduct basic research on the interaction between intestinal microorganisms (inactivated form) and host purine metabolism-related enzymes, and the regulation of enzyme activity in vivo, providing functionally defined experimental materials for research related to the "microbe-metabolic enzyme axis." This model strain includes inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0101] Based on this, the embodiments of this application also provide a control strain for screening the inhibitory activities of XOD and ADA enzymes in vivo. Its inactivated bacterial cells are used to construct a high-throughput screening model for the inhibitory activities of purine metabolism-related enzymes in vivo, assisting in the activity verification and screening of strains, natural products, and food ingredients with similar enzyme inhibitory potential in the food and microbiology fields, serving as a positive control benchmark. This control strain contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0102] Based on this, the embodiments of this application also provide a research strain for experiments on enzyme metabolism regulation in animals. The inactivated bacterial cells are used in laboratory animals to study the regulation of purine metabolism-related enzyme activities, exploring the effects of inactivated probiotics on the expression and activity of XOD and ADA enzymes in the host. This is for experimental research purposes only and does not involve disease intervention. This research strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0103] Based on this, embodiments of this application also provide a food functional ingredient with in vivo XOD and ADA enzyme inhibitory properties, wherein its inactivated bacterial cells are made into food-grade freeze-dried bacterial powder and added to common foods such as yogurt, fermented milk, plant-based beverages, meal replacement powders, and cereal products. This food functional ingredient contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with preservation number CGMCC NO.37034.

[0104] Based on this, the embodiments of this application also provide an intervention strain for regulating enzyme metabolism in laboratory animals. The inactivated bacterial cells are used in experiments related to the regulation of metabolic enzyme activity in laboratory animals to explore the regulatory mechanisms of inactivated microbial cells on metabolic enzymes such as XOD and ADA in laboratory animals, providing experimental data support for research on microbial metabolic regulation. This intervention strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0105] Based on this, the embodiments of this application also provide an auxiliary bacterial strain for studying the correlation between intestinal microecology and enzyme metabolism in experimental animals. The inactivated bacterial cells are used to study the correlation between the structure of the intestinal flora and the activity of enzymes related to purine metabolism in vivo. This strain is used solely as experimental research material and is not for the treatment / prevention of diseases in experimental animals. This auxiliary strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCCNO.37034.

[0106] Based on this, the embodiments of this application also provide an extraction raw material as an active ingredient for inhibiting XOD and ADA enzymes in vivo. Using inactivated *Lactobacillus plantarum* cells as the raw material, components with in vivo enzyme inhibitory activity (such as cell wall polysaccharides, polypeptides, and residual metabolites of inactivated cells) are extracted through physical and chemical methods. These active ingredients are used only as raw materials for food additives and experimental reagents, and not for the production of pharmaceuticals or health products. The extracted raw material contains inactivated *Lactobacillus plantarum* LPU3 cells with accession number CGMCC NO.37034.

[0107] Test Example 6: Lactobacillus plantarum LPU3 and its inactivated form (LPU3_P) improve kidney damage caused by hyperuricemia.

[0108] After the in vivo experiments were completed, livers, kidneys, and blood were collected from mice in each group, and kidney index, blood urea nitrogen, and creatinine were measured.

[0109] like Figure 6 As shown, the kidney index in the MC and ADC groups was significantly higher than that in the NC group, and the kidneys appeared pinkish-white, indicating kidney enlargement and transformation into uric acid nephropathy. The kidney index in the LPU3 group was significantly lower than that in the NC group, with no significant difference; the kidneys appeared dark red, also with no significant difference from the NC group. The kidney index in the LPU3_P group decreased, but did not reach a significant level.

[0110] like Figure 7 As shown, creatinine and blood urea nitrogen levels in the MC and ADC groups were significantly higher than those in the NC group. After LPU3 intervention, creatinine and blood urea nitrogen levels significantly decreased. After LPU3_P intervention, creatinine and blood urea nitrogen levels also significantly decreased. Creatinine and blood urea nitrogen are indicators for evaluating kidney function. Elevated levels of creatinine and blood urea nitrogen in the blood indicate renal insufficiency, potentially indicating kidney failure, nephritis, acute tubular necrosis, or other complications. In other words, the live LPU3 strain provided in this application has a protective effect against kidney damage caused by hyperuricemia after in vivo intervention, and its inactivated strain also has a similar protective effect against kidney damage caused by hyperuricemia after in vivo intervention.

[0111] Based on this, this application also provides a model strain for studying the physiological protective mechanism of experimental animal kidney tissue. Its inactivated bacterial cells are used in the laboratory to conduct basic research on the physiological interaction between microorganisms (inactivated form) and experimental animal kidney tissue, and the physiological regulation of the gut-kidney axis, providing functionally defined experimental materials for studying the microecological mechanisms of animal kidney physiological protection. This model strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0112] Based on this, the embodiments of this application also provide a control strain for screening the physiological protective activity of kidneys in experimental animals. The inactivated bacterial cells are used to construct a high-throughput screening model for the physiological protective activity of kidney tissues in experimental animals, assisting in the activity verification and screening of strains, natural products, and food ingredients with similar potential for kidney physiological protection in the food and microbiology fields, serving as a positive control benchmark. This control strain contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0113] Based on this, the embodiments of this application also provide a research strain for regulating the physiological homeostasis of experimental animals. The inactivated bacterial cells are used in the laboratory to investigate the regulatory mechanisms of inactivated microbial cells on the physiological state and morphology of kidney tissue in experimental animals. This is for experimental research purposes only and does not involve disease intervention. This research strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0114] Based on this, the embodiments of this application also provide an intervention strain for regulating the physiological state of experimental animal kidney tissue. The inactivated bacterial cells are used in laboratory animal kidney physiology-related experiments to explore the regulatory effects of inactivated probiotics on the morphology and physiological indicators of experimental animal kidney tissue, providing data support for experimental animal physiological research. This intervention strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0115] Based on this, this application also provides an auxiliary bacterial strain for studying the physiological correlation between the gut-kidney axis in experimental animals. The inactivated bacterial cells are used to study the correlation between the gut microbiota and the physiological state of kidney tissue in experimental animals, and are only used as experimental research material, not for the treatment / prevention of kidney-related diseases in experimental animals. This auxiliary strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCCNO.37034.

[0116] Based on this, the embodiments of this application also provide an extraction raw material as an active ingredient for protecting the kidney physiology of experimental animals. Using inactivated *Lactobacillus plantarum* cells as the raw material, components with protective activity for the kidney physiology of experimental animals (such as cell wall polysaccharides, polypeptides, and residual metabolites of inactivated cells) are extracted through physical and chemical methods. This active ingredient is only used as a raw material for food additives, experimental reagents, and biological additives for animal husbandry, and is not used in the production of pharmaceuticals or health products. The extraction raw material contains inactivated *Lactobacillus plantarum* LPU3 cells with accession number CGMCC NO.37034.

[0117] Test Example 7: Lactobacillus plantarum LPU3 and its inactivated form (LPU3_P) improve kidney inflammation and oxidative stress caused by hyperuricemia.

[0118] After the experiment, kidney tissues from all mice were collected, HE sections were prepared, and inflammatory factors (IL-1β, IL-18, TNF-α) and cellular oxidative stress (MDA) levels were detected.

[0119] See results Figure 8 In the NC group, the renal tubules and glomeruli were clearly morphologically distinct with no obvious lesions. In the MC group, the glomeruli were enlarged, the tubular lumens were dilated, the renal epithelial cell nuclei disappeared, necrosis was observed, and the renal interstitium was filled with inflammatory cells. The pathological condition of the kidneys in the LPU3 group was significantly improved compared to the MC group, with normal glomerular and tubular morphology and a reduction in inflammatory cells in the renal interstitium. However, in the LPU3_P group, some tubular lumens were still dilated, and inflammatory cells infiltrated the interstitium. Meanwhile, the pathological condition of the kidneys in the ADC group showed no significant improvement compared to the MC group, and the necrotic area was even more extensive.

[0120] like Figure 9 As shown, compared with the NC group, the MC group had significantly higher levels of TNF-α, IL-1β, IL-18, and MDA in the kidneys, indicating that high uric acid led to inflammatory responses and stress damage in the kidneys. After LPU3 intervention, the levels of TNF-α, IL-1β, IL-18, and MDA were significantly lower than in the MC group, while the levels of TNF-α, IL-1β, IL-18, and MDA in the LPU3_P and ADC groups showed no significant change compared to the MC group. This result demonstrates that LPU3 can protect the kidneys and reduce kidney inflammation and stress damage. LPU3_P also has a protective effect on the kidneys.

[0121] Test Example 8: Lactobacillus plantarum LPU3 and its inactivated cells (LPU3_P) improve intestinal flora imbalance caused by hyperuricemia.

[0122] After the in vivo experiment, cecal tissues of mice from each group were collected, and 16S rRNA amplicon sequencing analysis was performed on the contents of the mouse cecal tissues.

[0123] like Figure 10 The Venn plot shows that the MC and ADC groups have fewer OUT values ​​than the LPU3 and LPU3_P groups.

[0124] like Figure 11 Alpha-diversity analysis showed that, compared with the NC group, the MC group had decreased Chao and Shannon indices and significantly increased Simpson indices, indicating that hyperuricemia leads to a decrease in gut microbiota richness and diversity. LPU3 intervention significantly increased Chao and Shannon indices and decreased Simpson indices, demonstrating that LPU3 can improve gut microbiota richness and diversity. LPU3_P intervention significantly reduced Simpson indices and increased microbiota richness.

[0125] like Figure 12β-diversity analysis showed that the MC and NC groups were too far apart on the PCOA map, with p-values ​​less than 0.01, indicating differences in community composition between the MC and NC groups. The LPU3 and LPU3_P groups were closer to the NC group on the PCOA map, suggesting that LPU3 and LPU3_P interventions could reduce changes in gut microbiota structure. Combining the α and β-diversity analyses, it is clear that both LPU3 and LPU3_P can reduce the damage to the gut microbiota caused by hyperuricemia in mice.

[0126] The gut microbiota was analyzed. GMHI (Gut Microbial Health Index) and MDI (Mutual Disorder Index) are indicators of gut microbiota health; a higher GMHI value indicates a healthier gut microbiota, while a higher MDI value indicates a greater degree of dysbiosis. Figure 13 As shown, compared with the NC group, the GMHI values ​​of the MC and ADC groups were significantly lower, and the MDI values ​​were significantly higher, indicating that the gut microbiota was in a state of disorder. Compared with the MC group, the GMHI values ​​of the LPU3 and LPU3_P groups were significantly higher, and the MDI values ​​were significantly lower, indicating that the LPU3 and LPU3_P interventions restored the healthy state of the gut microbiota.

[0127] Figure 14 The statistical results of the intestinal hilum level in each group of mice are shown. Figure 14 As shown, hyperuricemia in MC group mice can induce a significant imbalance in the gut microbiota at the phylum level, specifically manifested as a significant decrease in Firmicutes abundance, a significant increase in Bacteroidetes abundance, and a significant decrease in the F / B ratio. This pattern of "decreased Firmicutes and increased Bacteroidetes" is highly consistent with the dysbiosis characteristics of diseases such as metabolic syndrome and inflammatory bowel disease, suggesting that gut microbiota dysbiosis may be an important link in the pathological mechanism of hyperuricemia. Based on the comparison results between the LPU3 group and the MC group, it can be seen that intervention with live or inactivated LPU3 strains (LPU3_P group) can more effectively reverse the dysbiosis, increasing Firmicutes, decreasing Bacteroidetes, and restoring the F / B ratio. Therefore, it can be seen that not only can the live LPU3 bacteria provided in this application improve the symptoms of "reduction of Firmicutes and increase of Bacteroidetes" in hyperuricemic mice, but the inactivated bacteria of the LPU3 strain can also play a role. This indicates that the strain can not only play a role in regulating the microbial community through colonization, but also indirectly affect the microbial community structure by regulating the host's metabolism or immune status through the inactivated bacteria.

[0128] Based on this, this application also provides a model strain for studying the physiological regulation mechanism of Firmicutes / Bacteroidetes in the intestinal phylum of experimental animals. Its inactivated bacterial cells are used in the laboratory to conduct basic research on the interaction between microorganisms (inactivated form) and the intestinal flora of experimental animals, and the physiological regulation of Firmicutes / Bacteroidetes, providing functionally defined experimental materials for the study of the mechanism of intestinal microecological phylum structural regulation. This model strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0129] Based on this, the embodiments of this application also provide a control strain for screening the abundance regulation activity of Firmicutes / Bacteroidetes in the intestinal tract of experimental animals. Its inactivated bacterial cells are used to construct a high-throughput screening model for the abundance regulation activity of Firmicutes / Bacteroidetes in the intestinal tract of experimental animals, assisting in the activity verification and screening of strains, natural products, and food ingredients with similar phylum regulatory potential in the food and microbiology fields, serving as a positive control benchmark. This control strain contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCCNO.37034.

[0130] Based on this, the embodiments of this application also provide experimental strains for studying the relationship between intestinal flora structure and host physiology. The inactivated bacterial cells are used in the laboratory to investigate the impact of changes in the abundance of Firmicutes and Bacteroidetes on the overall structure of the intestinal microecology of experimental animals. This is for experimental research purposes only and does not involve disease intervention. The experimental strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCCNO.37034.

[0131] Based on this, the embodiments of this application also provide an intervention strain for the structural and physiological regulation of Firmicutes and Bacteroidetes in the intestinal phylum of laboratory animals. The inactivated bacterial cells are used in laboratory animal intestinal microecology-related experiments to explore the regulatory effects of inactivated probiotics on the abundance and overall structure of Firmicutes and Bacteroidetes in the intestinal phylum of laboratory animals, providing data support for laboratory animal microecology research. This intervention strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0132] Based on this, this application also provides an auxiliary strain for constructing a model of Firmicutes / Bacteroidetes imbalance in the intestinal flora of experimental animals. Its inactivated bacterial cells are used to artificially regulate the abundance of Firmicutes / Bacteroidetes in the intestinal flora of experimental animals in the laboratory, constructing a standardized animal model of abnormal intestinal flora structure, and providing a unified experimental model material for similar microecological regulation studies. This auxiliary strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0133] Based on this, this application also provides an extraction raw material as a regulatory active ingredient for Firmicutes / Bacteroidetes in the intestinal tract of experimental animals. Using inactivated *Lactobacillus plantarum* cells as the raw material, components with regulatory activity on the abundance of Firmicutes / Bacteroidetes in the intestinal tract of experimental animals (such as cell wall polysaccharides, polypeptides, and residual metabolites of inactivated cells) are extracted using physical and chemical methods. This active ingredient is only used as a raw material for food additives, experimental reagents, and biological additives for animal husbandry, and is not used in the production of pharmaceuticals or health products. The extracted raw material contains inactivated *Lactobacillus plantarum* LPU3 cells with accession number CGMCC NO.37034.

[0134] Based on this, this application also provides an industrially produced strain of *Lactobacillus plantarum* as a functional microecological biological raw material. After large-scale fermentation and cultivation, the *Lactobacillus plantarum* is subjected to standardized inactivation treatment to produce a high-purity inactivated bacterial powder. This powder serves as a biological raw material with characteristics that regulate the abundance of Firmicutes / Bacteroidetes in the intestinal tract of laboratory animals, and is supplied to fields such as food processing, experimental research, and food-grade formulation production, reflecting only the experimental physiological characteristics of the raw material. This industrially produced strain contains inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0135] Based on this, this application also provides a feed additive for livestock / poultry / aquaculture, inactivated bacterial cells of which are added to the basic feed or compound feed of farmed animals. Utilizing their regulatory properties on the structure of Firmicutes / Bacteroidetes in the animal's intestine, they optimize the composition of the intestinal flora, improve intestinal digestion and absorption, and increase feed conversion rate. This focuses solely on optimizing the production performance and intestinal microecological physiological state of farmed animals and does not involve the treatment of any animal diseases. This feed additive contains inactivated bacterial cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0136] Figure 15 The statistical results at the gut microbiota level in each group of mice are shown. Figure 15 As shown, in the MC group, the number of key beneficial bacteria for uric acid metabolism (Lactobacillus) was significantly reduced. These bacteria can reduce uric acid absorption by degrading uric acid and regulating the intestinal barrier. Meanwhile, the number of pro-inflammatory and metabolic disorder-related bacteria (Bacteroides, Biliophilus, Myxospira, and Coridella) was significantly increased. Biliophilus metabolizes bile acids, promoting uric acid reabsorption; excessive proliferation of Bacteroides damages the intestinal barrier; and Myxospira and Coridella are positively correlated with metabolic inflammation, collectively exacerbating the progression of hyperuricemia.

[0137] The results from the LPU3 group showed that LPU3 live bacteria significantly increased the abundance of *Lactobacillus* spp., and the enrichment of *Lactobacillus* spp. was a unique effect of LPU3 live bacteria, suggesting that colonization and metabolic activity of live bacteria are key. In addition, LPU3 live bacteria significantly reduced the abundance of *Bacillus* spp., *Bacteroides* spp., *Myxospira* spp., and *Coridella* spp., directly breaking the vicious cycle of dysbiosis and inflammation-induced abnormal uric acid metabolism.

[0138] Based on this, this application provides model strains for studying the abundance regulation mechanisms of *Bacteroides*, *Bacteroides*, *Myxobolus*, and *Coridella* genera in the intestinal tract of laboratory animals. The live bacterial cells are used in the laboratory to conduct research on the interaction between microorganisms and specific bacterial genera in the intestinal tract of laboratory animals, and to explore the molecular mechanisms of targeted regulation of intestinal bacteria, providing functionally defined experimental materials for the field of regulation of specific bacterial genera in the intestinal microecology. This model strain contains live cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0139] Based on this, this application provides a control strain for screening the inhibitory activity of *Bacillus*, *Bacteroides*, *Myxospira*, and *Coridella* species in the intestinal tract of laboratory animals. The live bacterial cells are used to construct a high-throughput screening model for reducing the abundance of *Bacillus*, *Bacteroides*, *Myxospira*, and *Coridella* species in the intestinal tract of laboratory animals. This model assists in the activity verification and screening of strains, natural products, and food ingredients with similar genus regulatory potential in the food and microbiology fields, serving as a positive control benchmark. This control strain contains live cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0140] Based on this, the embodiments of this application provide experimental strains for studying the correlation between intestinal bilirubin, Bacteroides, Myxobolus, and Coridella and the host's microecological balance. The live bacterial cells are used in the laboratory to investigate the impact of changes in the abundance of bilirubin and other genera on the overall structure and homeostasis of the intestinal flora of experimental animals. This is solely for basic research purposes and does not involve any disease intervention. The experimental strain contains live cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0141] Based on this, this application provides a food-grade functional ingredient that has the characteristic of regulating the abundance of *Bacteroides*, *Bacteroides*, *Myxospira*, and *Coridella* in the intestines of laboratory animals. The live bacterial cells are made into a food-grade freeze-dried bacterial powder and added to common fermented / non-fermented foods such as yogurt, fermented milk, fermented soy products, cereal meal replacement powders, and plant-based beverages. The label only states "contains live *Lactobacillus plantarum* cells that can reduce the abundance of *Bacteroides*, *Bacteroides*, *Myxospira*, and *Coridella* in the intestines of laboratory animals," reflecting only the animal experimental physiological characteristics of the strain, without any claims of health benefits or disease treatment. This food-grade functional ingredient contains live *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

[0142] Based on this, the embodiments of this application provide a fermentation strain for functional fermented foods, which can be directly used as a starter in the production of foods such as yogurt, kimchi, and fermented grains, or added in the later stages of fermentation. Utilizing its unique animal experimental characteristics in regulating the flora of *Bacteroides*, *Bacteroides*, *Myxobolus*, and *Corydalis*, it enriches the functional dimensions of the food, focusing solely on optimizing the functional characteristics and improving fermentation quality, without relating to any human physiological indicators, and without claiming any health benefits. This fermentation strain contains live cells of *Lactobacillus plantarum* LPU3 with preservation number CGMCC NO.37034.

[0143] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A strain of Lactiplantibacillus plantarum LPU3, which is Lactiplantibacillus plantarum LPU3 with accession number CGMCC NO.37034.

2. A uric acid degradation agent comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3 as described in claim 1.

3. An inhibitor of xanthine oxidase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3 as described in claim 1.

4. An inhibitor of adenosine deaminase, comprising at least one or more of the following: dead cells, live cells, inactivated cells, metabiotics, and fermentation broth of *Lactobacillus plantarum* LPU3 as described in claim 1.

5. An inactivated bacterial cell of Lactiplantibacillus plantarum, wherein the Lactiplantibacillus plantarum is LPU3 with accession number CGMCC NO.37034, and the inactivated bacterial cell is a bacterial cell that has no replication ability after inactivation treatment.

6. A type strain comprising inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

7. A control strain comprising inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

8. An intervention strain comprising inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034.

9. An auxiliary strain comprising inactivated cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034.

10. The application of Lactobacillus plantarum LPU3 according to claim 1, wherein the application is selected from any one or more of the following: Uric acid degradation agents; Inhibitors of xanthine oxidase; Inhibitors of adenosine deaminase; To prepare products that help regulate uric acid metabolism; To develop products that improve the balance of gut microbiota; To prepare products that alleviate renal oxidative stress induced by hyperuricemia; Preparation of dried body; As a control strain for in vitro uric acid-lowering activity assay, inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034 were included. As an experimental strain for regulating the in vitro uric acid system, it includes inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034; The quality control strain for in vitro uric acid detection experiments includes inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As a standard bacterial agent for in vitro uric acid-lowering activity experiments, it contains inactivated bacterial cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034; As an additive for regulating purine / uric acid in animal feed, it contains inactivated Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034; As a standard strain or reagent for screening in vitro XOD enzyme inhibition activity, the standard strain or reagent contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As experimental material for studying the enzymatic reaction mechanism of XOD enzyme, this experimental material contains inactivated bacterial cells of Lactobacillus plantarum LPU3 with the preservation number CGMCC NO.37034; As a performance validation reagent for the XOD enzyme activity assay kit, this performance validation reagent contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034; As an in vitro purification aid for processing high-purine substrate foods, this in vitro purification aid contains inactivated cells of Lactobacillus plantarum LPU3 with preservation number CGMCCNO.37034; As a model strain for studying the regulatory mechanisms of XOD and ADA enzymes in vivo, this model strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As a control strain for screening the inhibitory activity of XOD and ADA enzymes in vivo, the control strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As a research strain for experiments on the metabolic regulation of XOD and ADA enzymes in animals, this research strain contains inactivated cells of Lactobacillus plantarum LPU3 with the preservation number CGMCCNO.37034. As a functional food ingredient with the properties of inhibiting XOD and ADA enzymes in vivo, this functional food ingredient contains inactivated cells of Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034. As an intervention strain for the metabolic regulation of XOD and ADA enzymes in experimental animals, this intervention strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As an auxiliary strain for studying the association between the intestinal microecology of experimental animals and XOD enzyme and ADA metabolism, this auxiliary strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As an extract of active ingredients that inhibit XOD and ADA enzymes in vivo, the extract contains inactivated cells of Lactobacillus plantarum LPU3 with preservation number CGMCCNO.37034. As a model strain for studying the physiological protective mechanism of kidney tissue in experimental animals, this model strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As a control strain for screening the physiological protective activity of experimental animal kidneys, the control strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As an intervention strain for regulating the physiological state of kidney tissue in experimental animals, this intervention strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As an auxiliary strain for studying the physiological association of the gut-kidney axis in experimental animals, this auxiliary strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As an extract of the active ingredient for protecting the kidney physiology of experimental animals, the extract contains inactivated cells of Lactobacillus plantarum LPU3 with the preservation number CGMCCNO.37034. As a model strain for studying the physiological regulation mechanism of Firmicutes / Bacteroidetes in the gut of experimental animals, this model strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As a control strain for screening the abundance regulation activity of Firmicutes / Bacteroidetes in the intestinal phylum of experimental animals, the control strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As an experimental strain for studying the relationship between the structure of the gut microbiota and host physiology, this experimental strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCCNO.37034. As an intervention strain for the structural and physiological regulation of Firmicutes and Bacteroidetes in the gut of experimental animals, this intervention strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As an auxiliary strain for constructing an experimental animal intestinal Firmicutes / Bacteroidetes flora imbalance model, this auxiliary strain contains inactivated cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As an extract of active ingredients that regulate Firmicutes / Bacteroidetes in the gut of laboratory animals, the extract contains inactivated cells of Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034. As an industrial production strain of functional microecological biological raw materials, the industrial production strain contains inactivated cells of Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034. As a feed additive for livestock / poultry / aquaculture, this feed additive contains inactivated Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034; As a model strain for studying the abundance regulation mechanism of Bacteroides, Bacteroides, Myxospira, and Coridella in the intestine of experimental animals, this model strain contains live cells of Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034. This control strain was used as a screening strain for the inhibitory activity against the abundance of *Bacillus*, *Bacteroides*, *Myxobolus*, and *Coridella* in the intestines of laboratory animals. The control strain contained live cells of *Lactobacillus plantarum* LPU3 with accession number CGMCC NO.37034. As an experimental strain for studying the association between intestinal bilirubin, Bacteroides, Myxospira, and Coridella and the host microecological balance, this experimental strain contains live cells of Lactobacillus plantarum LPU3 with accession number CGMCC NO.37034. As a food-grade functional ingredient with the characteristic of regulating the abundance of Bacteroides, Bacteroides, Myxobolus and Coridella in the intestines of laboratory animals, this food-grade functional ingredient contains live Lactobacillus plantarum LPU3 with preservation number CGMCC NO.37034. As a fermentation strain for functional fermented foods, this fermentation strain contains live cells of *Lactobacillus plantarum* LPU3 with preservation number CGMCC NO.37034.

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