Lactobacillus paracasei nefu-5 and application thereof

Abstract

This invention relates to *Lactobacillus paracasei* NEFU-5 and its applications, belonging to the field of biotechnology. To address the problems of limited functionality and poor direct degradation of metabolites in existing probiotic strains, this invention provides *Lactobacillus paracasei* NEFU-5 (accession number CCTCC NO: M 2026147). This *Lactobacillus paracasei* NEFU-5 can simultaneously and efficiently degrade uric acid, triglycerides, and cholesterol, and possesses excellent probiotic properties and safety. The *Lactobacillus paracasei* NEFU-5 provided by this invention can be used to prepare fermented products and can be used to prevent or improve hyperuricemia, hyperlipidemia, and other concurrent metabolic diseases, showing significant application prospects.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, and in particular relates to a type of Lactobacillus paracasei and its applications. Background Technology

[0002] With changes in modern lifestyles and dietary structures, the incidence of metabolic syndrome and related diseases has been rising year by year, becoming a global public health problem. Metabolic syndrome typically manifests as a cluster of metabolic abnormalities, mainly including complications such as hyperuricemia (HUA), hypertriglyceridemia (HTG), and hypercholesterolemia (HC). These abnormalities are risk factors for cardiovascular disease, type 2 diabetes, non-alcoholic fatty liver disease, and gout. Among them, hyperuricemia is a chronic metabolic disease caused by purine metabolism disorders leading to elevated blood uric acid levels. It is not only a direct cause of gout but is also closely related to hypertension, kidney disease, and insulin resistance. Abnormal blood lipids, especially elevated triglycerides (TRIG) and cholesterol (TC), can easily lead to atherosclerosis and significantly increase the risk of cardiovascular and cerebrovascular events.

[0003] Currently, the treatment of these metabolic abnormalities mainly relies on chemical drugs, such as allopurinol and febuxostat for lowering uric acid, and statins and fibrates for lowering blood lipids. However, long-term use may lead to side effects such as liver damage, muscle toxicity, and gastrointestinal discomfort, and there is a risk of drug resistance. Therefore, developing safe, long-acting alternative or adjuvant therapies with multi-target regulatory effects has become a key research direction and challenge.

[0004] In recent years, probiotics have shown promising prospects in the prevention and treatment of metabolic diseases due to their high safety, wide range of effects, multi-target nature, and low toxicity. Lactic acid bacteria, as common probiotics, can exert health benefits by regulating the intestinal flora, improving barrier function, and influencing host metabolism and immunity. Existing research indicates that some lactic acid bacteria have certain uric acid-lowering or cholesterol-lowering functions. For example, some strains can degrade intestinal purines or inhibit xanthine oxidase to lower uric acid, while others lower cholesterol by binding bile salts and promoting excretion. However, current research and application of probiotics still have significant limitations. Most reported lactic acid bacteria strains with metabolic regulatory functions focus on a single indicator, with few strains capable of simultaneously and efficiently acting on the three key metabolic indicators of uric acid, triglycerides, and cholesterol. Furthermore, the "lipid-lowering" or "uric acid-lowering" effects of these strains largely rely on indirect intestinal environment regulation or host physiological regulation, exhibiting weak direct in vitro degradation capabilities of substrates and limited efficacy. For patients with both high uric acid and high blood lipids, there is a lack of probiotic resources that can simultaneously intervene and simplify treatment. Summary of the Invention

[0005] To address the problems of limited functionality and poor direct degradation of metabolites in existing probiotic strains, this invention provides Lactobacillus paracasei NEFU-5 and its applications.

[0006] One of the objectives of this invention is to provide a Lactobacillus paracasei NEFU-5, wherein Lactobacillus paracasei NEFU-5 ( Lactobacillus paracasei The accession number for NEFU-5 is CCTCC NO: M 2026147, and it is classified as follows: Lactobacillus paracasei NEFU-5 is deposited at the China Center for Type Culture Collection on January 16, 2026.

[0007] A second objective of this invention is to provide a microbial agent containing the aforementioned Lactobacillus paracasei NEFU-5.

[0008] A third objective of this invention is to provide the application of the aforementioned *Lactobacillus paracasei* NEFU-5 or its agent in the preparation of a drug, which has the following functions: degrading uric acid and relieving hyperuricemia; degrading triglycerides and cholesterol and relieving hyperlipidemia; and reducing inflammatory factors. Compared with the prior art, the beneficial effects of the present invention are: the present invention provides a Lactobacillus paracasei (NEFU-5) and a bacterial agent containing the strain, wherein the Lactobacillus paracasei NEFU-5 has the accession number CCTCC NO: M 2026147.

[0009] The *Lactobacillus paracasei* NEFU-5 provided by this invention can achieve an in vitro uric acid degradation rate of 74.88%, a triglyceride degradation rate of 58.48%, and a cholesterol degradation rate of 41.6%. It can reduce the serum uric acid content in hyperuricemia and hyperlipidemia dual-model mice from 290.432 μmol / L to 98.747 μmol / L, the triglyceride content from 1.645 mmol / L to 0.823 mmol / L, and the cholesterol content from 7.015 mmol / L to 4.712 mmol / L.

[0010] In vitro and in vivo experiments have verified that the Lactobacillus paracasei NEFU-5 provided by this invention exhibits significant anti-inflammatory effects and can effectively reduce the levels of inflammatory factors in the kidneys and livers of mice with hyperuricemia and hyperlipidemia. The strain can directly degrade uric acid, triglycerides and cholesterol, thereby alleviating hyperuricemia and hyperlipidemia, regulating the composition of intestinal flora and reducing inflammatory responses.

[0011] This invention provides new strains of bacteria for the development of probiotic preparations and functional foods that have both uric acid-lowering and blood lipid-lowering functions. These strains can be used to prevent or improve hyperuricemia, hyperlipidemia and other concurrent metabolic diseases, and have significant application prospects.

[0012] [Biological Preservation Information]: The preservation number for *Lactobacillus paracasei* NEFU-5 is CCTCC NO: M 2026147, and its classification name is... Lactobacillus paracasei NEFU-5 is deposited at the China Center for Type Culture Collection on January 16, 2026. Attached Figure Description

[0013] Figure 1 This is a graph showing the screening results of uric acid-degrading strains; the vertical axis represents the UA degradation rate, which is the uric acid degradation rate. Figure 2 This is a graph showing the screening results of triglyceride-degrading strains; the vertical axis represents the TRIG degradation rate, which is the triglyceride degradation rate. Figure 3 This is a graph showing the screening results of cholesterol-degrading strains; the vertical axis represents the cholesterol degradation rate (TC degradation rate). Figure 4 Electron micrograph of Lactobacillus paracasei NEFU-5 colonies; Figure 5 This is a colony morphology diagram of Lactobacillus paracasei NEFU-5. Figure 6 The image shows the results of homology comparison analysis of Lactobacillus paracasei NEFU-5. Figure 7 This is a graph showing the results of a hemolysis test. Figure 8 The image shows the results of the indole test; from left to right, the negative control group, the Lactobacillus paracasei NEFU-5 group, and the blank control group. Figure 9 This is a statistical graph of DPPH free radical scavenging capacity; the vertical axis represents DPPH free radical scavenging rate; the horizontal axis represents ascorbic acid. Figure 10 This is a statistical graph of ABTS radical scavenging capacity; the vertical axis represents ABTS radical scavenging rate. Figure 11 This is an automatically aggregated statistical chart; the vertical axis, Auto-aggregation, represents the automatic aggregation rate; the horizontal axis, Time, represents time. Figure 12 This is a statistical graph of cell surface hydrophobicity measurement; the vertical axis represents cell surface hydrophobicity; Xylene represents xylene; Ethyl acetate represents ethyl acetate; Chloroform represents chloroform. Figure 13 A statistical chart showing the degradation rates of uric acid, triglycerides, and cholesterol in Lactobacillus paracasei NEFU-5; Figure 14 A statistical graph showing the IL-1β content in the kidneys of mice in different groups; the vertical axis represents the IL-1β content in the kidneys. Figure 15 A statistical graph showing the IL-1β content in the livers of mice in different groups; the vertical axis, Liver IL-1β, represents the IL-1β content in the liver. Detailed Implementation

[0014] Those skilled in the art can refer to the content of this document and appropriately improve the process parameters to achieve the desired results. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate alterations and combinations to the methods and applications described herein without departing from the content and scope of this invention to implement and apply the technology of this invention.

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the materials, reagents, methods, and instruments used are all conventional materials, reagents, methods, and instruments in the art, and can be obtained commercially by those skilled in the art.

[0016] The Lactobacillus paracasei NEFU-5 described in the following examples has the accession number CCTCC NO: M 2026147 and is classified as follows: Lactobacillus paracasei NEFU-5 is deposited at the China Center for Type Culture Collection on January 16, 2026.

[0017] Example 1: Isolation, screening and identification of Lactobacillus paracasei NEFU-5 1. Isolation and Screening of Strains: Homemade sauerkraut from Xiangfang District, Harbin City, Heilongjiang Province was selected as the sample. Solid and liquid samples of the sauerkraut were added to MRS medium (composition: 10 g peptone, 10 g beef extract, 10 g yeast extract, 20 g glucose, 1.0 mL Tween 80, 2.0 g dipotassium hydrogen phosphate, 5 g sodium acetate, 2 g triammonium citrate, 0.1 g magnesium sulfate, 0.05 g manganese sulfate, dissolved in 1 L distilled water, pH 6-7, sterilized at 121℃ for 20 min). The medium was incubated at 28-37℃ and 50-200 r / min with shaking for 20-28 hours. After dilution, the culture was spread onto MSM inorganic salt medium (17.1 g disodium hydrogen phosphate, 3.0 g potassium dihydrogen phosphate, 0.5 g sodium chloride, 0.01 g calcium chloride, 0.5 g magnesium sulfate, 15 g agar, 0.336 g uric acid) with uric acid as the sole carbon and nitrogen source. Sterilize a plate with 1000 mL of distilled water (sterilized at 0.1 MPa for 20 min), let it stand, and incubate at 37℃ for 48 h. Select milky-white colonies and screen for single colonies with typical Lactobacillus characteristics. Place these single colonies on MRS solid medium (composition: 10 g peptone, 10 g beef extract, 10 g yeast extract, 20 g glucose, 1.0 mL Tween 80, 2.0 g dipotassium hydrogen phosphate, 5 g sodium acetate, 2 g triammonium citrate, 0.1 g magnesium sulfate, 0.05 g manganese sulfate, 10-20 g agar powder dissolved in 1 L distilled water, pH 6-7, sterilized at 121℃ for 20 min) and streak repeatedly to purify until single-morphological colonies appear. Pick a single colony and inoculate it on MRS liquid medium (composition: 10 g peptone, 10 g beef extract, 10 g yeast extract, 20 g glucose, 1.0 mL Tween 80, 1.0 mL dipotassium hydrogen phosphate, 2.0 g sodium acetate, 2 g triammonium citrate, 0.1 g magnesium sulfate, 0.05 g manganese sulfate, 10-20 g agar powder dissolved in 1 L distilled water, pH 6-7, sterilized at 121℃ for 20 min) to purify it. Dissolve 2.0 g of dipotassium hydrogen phosphate, 5 g of sodium acetate, 2 g of triammonium citrate, 0.1 g of magnesium sulfate, and 0.05 g of manganese sulfate in 1 L of distilled water at pH 6-7. Sterilize at 121℃ for 20 min, incubate, and then incubate at 37℃ for 48 h.

[0018] The above bacterial cultures were inoculated at a rate of 1% into MSM inorganic salt liquid medium with triglycerides as the sole carbon source. The cultures were shaken and cultured at 37°C for 72 h. At 12, 24, 36, 48, 60, and 72 h, 2 mL of fermentation broth was collected, centrifuged at 4°C and 6000 r / min, and the supernatant was collected. The triglyceride content in the supernatant was then determined, and strains with high triglyceride degradation rates were selected.

[0019] The above-mentioned strains were inoculated at a 1% inoculum in MSM inorganic salt liquid medium with cholesterol as the sole carbon source, and cultured with shaking at 37℃ for 72 h. At 12, 24, 36, 48, 60 and 72 h, 2 mL of fermentation broth was taken each time, centrifuged at 4℃ and 6000 r / min, and the supernatant was collected. The cholesterol content in the supernatant was detected, and strains with high cholesterol degradation rate were selected.

[0020] like Figure 1-3 As shown, lactic acid bacteria with high degradation capabilities for uric acid, triglycerides, and cholesterol were screened and obtained; their colony morphology was then observed, such as... Figure 4-5 As shown, the lactic acid bacteria obtained from the above screening were inoculated into MRS liquid medium and cultured statically at 37°C until the logarithmic phase. Glycerol with a final concentration of 30% was added and stored at -80°C.

[0021] 2. Identification of strains DNA from the obtained lactic acid bacteria strain was extracted using a bacterial genomic DNA extraction kit. PCR amplification was performed using universal primers 27F (nucleotide sequence shown in SEQ ID NO.1) and 1492R (nucleotide sequence shown in SEQ ID NO.2). The PCR amplification reaction system consisted of: 1 μL genomic DNA (20 ng / μL), 10× Buffer (containing 2.5 mM MgSO4), and 1 μL genomic DNA (20 ng / μL). 2+ 5 μL of Taq polymerase (5 u / μL), 1 μL of dNTP (10 mM), 1.5 μL each of primers 27F and 1492R (10 μM), and ddH2O to a final volume of 50 μL were added. The PCR amplification program was as follows: pre-denaturation at 95℃ for 5 min; denaturation at 95℃ for 30 s, annealing at 58℃ for 30 s, extension at 72℃ for 1.5 min, for 35 cycles; final extension at 72℃ for 7 min. The PCR amplification products were recovered using the AxyPrep DNA gel extraction kit and sent to Shanghai Paisennong Biotechnology Co., Ltd. for sequencing. The obtained sequences were compared with the GenBank database using BLAST software for homology analysis. Figure 6 As shown, the lactic acid bacteria strains obtained from the above screening can be identified as Lactobacillus paracasei, and they are named Lactobacillus paracasei NEFU-5; the 16S rRNA of Lactobacillus paracasei NEFU-5 is shown in SEQ ID NO.3.

[0022] Effect Experiment: 1. Safety evaluation (1) Hemolysis test: The Lactobacillus paracasei NEFU-5 obtained in Example 1 was placed at 37℃ and allowed to stand for 18-24 hours to obtain seed liquid. 1 mL of seed liquid was added to 9 mL of blank MRS liquid medium and incubated for 10 hours to obtain activated Lactobacillus paracasei NEFU-5. It was then streaked onto Columbia blood agar medium (composition: 5 g sodium chloride, 2 g glucose, 5 g peptone, 10 g trypone, 5 g yeast extract, 5 g beef extract, 15 g agar, 1000 mL distilled water, 60 mL defibrinated sheep blood). Escherichia coli (purchased from Yangling Ruizhi Weikang Biotechnology Co., Ltd. as a pathogenic indicator strain) was used as the control group. The culture was carried out at 37℃ for 48 hours. If a grass-green hemolysis ring appeared, it was α-hemolysis; if a colorless and transparent hemolysis ring appeared, it was β-hemolysis; if no hemolysis ring appeared, it was γ-hemolysis.

[0023] The results are as follows Figure 7 As shown, the control group of Escherichia coli showed obvious β-hemolytic rings (complete hemolysis, clear area), consistent with its known hemolytic characteristics; Lactobacillus paracasei NEFU-5 did not show hemolytic activity, indicating that it does not have a hemolysis-related pathogenic mechanism.

[0024] (2) Indole test Lactobacillus paracasei NEFU-5 was inoculated at a 2% inoculum into peptone water medium (composition: 10 g peptone, 5 g sodium chloride, 2 g disodium hydrogen phosphate, 2 g dipotassium hydrogen phosphate, 5 g glucose, 1000 mL distilled water), with physiological saline replacing the strain as a blank control; and cultured at 35℃ for 72 h. Two drops of xylene were added, the medium was shaken thoroughly, allowed to stand, and then 3-6 drops of indole reagent were added. The experimental results were then observed.

[0025] The results are as follows Figure 8 As shown, no red rose indole appeared in the upper layer of the test tube, indicating that Lactobacillus paracasei NEFU-5 was negative and did not produce indole-like substances.

[0026] 2. Antioxidant capacity determination (1) DPPH free radical scavenging ability: 100 μL of VC (concentration of 15 µg / mL) and 100 μL of 0.4 mM DPPH solution were added to a 96-well plate as the control group; 100 μL of Lactobacillus paracasei NEFU-5 obtained in Example 1 and 100 μL of 0.4 mM DPPH solution were added to a 96-well plate as the experimental group. The reaction was carried out at 25°C in the dark for 30 min, and the DPPH free radical scavenging ability of the lactic acid bacteria was determined based on the absorbance at 540 nm.

[0027] The results are as follows Figure 9As shown, the DPPH free radical scavenging rate of *Lactobacillus paracasei* NEFU-5 was 77.35%, which was closest to the DPPH free radical scavenging rate of the positive control vitamin C (86.54%). This indicates that the strain provided by this invention has a strong DPPH free radical scavenging ability.

[0028] (2) ABTS radical scavenging ability: 7.4 mM ABTS radical solution was reacted with 2.6 mM potassium persulfate for 24 h at room temperature in the dark to generate stable, high-concentration ABTS radical cations (ABTS· + ) Stock solution. Before measurement, use PBS to prepare the ABTS to be tested. + The stock solution was diluted at 734 nm to achieve an absorbance of 0.70 ± 0.03. 20 μL of VC (20 µg / mL) was added to a 96-well plate containing 180 μL of ABTS radical solution as a control group; 20 μL of *Lactobacillus paracasei* NEFU-5 bacterial culture obtained in Example 1 was added to a 96-well plate containing 180 μL of ABTS radical solution as an experimental group. The reaction was carried out at 25°C in the dark for 10 min, and the ABTS radical scavenging ability of the lactic acid bacteria was determined based on the absorbance at 734 nm.

[0029] The results are as follows Figure 10 As shown, the ABTS free radical scavenging rate of Lactobacillus paracasei NEFU-5 is 87.00%; indicating that the Lactobacillus paracasei NEFU-5 provided by the present invention has a strong ABTS free radical scavenging ability.

[0030] 3. Automatic aggregation ability measurement The *Lactobacillus paracasei* NEFU-5 obtained in Example 1 was grown overnight in MRS broth at 37°C, centrifuged, and washed twice with sterile PBS (pH=7.2). The broth was then resuspended in the supernatant and vortexed for 30 seconds. Using VC as a control group, the absorbance was measured at 600 nm using a UV-Vis spectrophotometer at different times (0, 1, 2, 3, 4, and 5 hours) to obtain the autoaggregation ability of *Lactobacillus paracasei* NEFU-5.

[0031] Automatic aggregation capability = [1-(A t / A0)]×100%.

[0032] A0: Initial absorbance value measured at 600 nm wavelength, with a time of 0 hours (i.e., immediately after the bacterial suspension is prepared and vortexed); A t : The absorbance value of the sample taken from the upper layer of the suspension at a wavelength of 600 nm, which is t hours.

[0033] Lactic acid bacteria can form a biological barrier in the intestine through self-agglutination. This characteristic not only helps probiotics colonize and proliferate in the intestine, but also competitively inhibits the colonization and infection of pathogenic bacteria. Figure 11 As shown, the self-aggregation rate of Lactobacillus paracasei NEFU-5 was 61.17% after 24 hours. This indicates that the Lactobacillus paracasei NEFU-5 provided by this invention has a significant self-aggregation ability, providing an important basis for it to form a stable barrier in the intestine and exert its probiotic function.

[0034] 4. Measurement of cell surface hydrophobicity The hydrophobicity of the cell surface of *Lactobacillus paracasei* NEFU-5 obtained in Example 1 was determined by the microbial adhesion hydrocarbon method (MATH).

[0035] After culturing *Lactobacillus paracasei* NEFU-5 obtained in Example 1 for 24 h, the cells were centrifuged and washed twice with PBS (pH=7.2). The cells were resuspended in 5 mL of PBS buffer, and the absorbance of the cell suspension was measured at 600 nm using a UV-Vis spectrophotometer, denoted as A0. The cell suspension was then mixed with an equal volume of solvent for 5 min to obtain a suspension. Measurements were performed using ethyl acetate (alkaline solvent), chloroform (acidic solvent), or xylene (non-polar solvent). The suspension was incubated at room temperature for 30 min to achieve phase separation. The absorbance of the aqueous phase at 600 nm was measured and denoted as A. t The hydrophobicity of the cell surface of Lactobacillus paracasei NEFU-5 was obtained.

[0036] Cell surface hydrophobicity = [(A0-A t ) / A0]×100%.

[0037] A0: Initial absorbance value measured at 600 nm wavelength, with a time of 0 hours (i.e., immediately after the bacterial suspension is prepared and vortexed); A t : The absorbance value of the sample taken from the upper layer of the suspension at a wavelength of 600 nm, which is t hours.

[0038] Higher cell surface hydrophobicity indicates stronger corresponding surface properties of the strain; results are as follows Figure 12As shown, *Lactobacillus paracasei* NEFU-5 exhibits a high adsorption rate of 76.64% for chloroform, indicating that the cell surface of *Lactobacillus paracasei* NEFU-5 provided by this invention is rich in electron donors (such as amino and hydroxyl groups) and possesses a strong Lewis basic region, which is consistent with the surface characteristics of most lactic acid bacteria. The adsorption rate of *Lactobacillus paracasei* NEFU-5 provided by this invention for xylene is at a moderate level of 60.97%, and the adsorption rate for ethyl acetate is 60.96%, indicating that its surface electron acceptors (such as carboxyl and phosphate groups) are relatively weak, and its affinity for basic solvents is slightly low.

[0039] As can be seen, the Lactobacillus paracasei NEFU-5 provided by the present invention exhibits the strongest surface hydrophobicity and electron donor properties, which suggests that it may have excellent adhesion and colonization potential.

[0040] 5. Tests for lowering uric acid, triglycerides, and cholesterol. (1) In vitro experiments The *Lactobacillus paracasei* NEFU-5 obtained in Example 1 was placed in MRS liquid medium and cultured statically at 37°C until the logarithmic growth phase. After centrifugation and three washes, it was resuspended in PBS and inoculated at a 2% (v / v) inoculum into MSM medium containing 0.336 g / L uric acid, 1.330 g / L triglycerides, and 0.580 g / L cholesterol. The medium was cultured at 37°C with shaking for 72 h. Every 12 h, the supernatant of the incubated culture was collected by centrifugation and filtered through a 0.22 μm filter membrane. The degradation of uric acid was detected by HPLC. The degradation rates of triglycerides and cholesterol were obtained by using a kit (purchased from Nanjing Jiancheng Biotechnology Research Institute).

[0041] Degradation rate (%) = [(C0-C t ) / C0]×100%.

[0042] C0: Initial concentrations of uric acid, triglycerides, and cholesterol in the culture medium after 0 hours of incubation (i.e., 0.841 g / L); C t The residual concentrations of uric acid, triglycerides, and cholesterol in the supernatant after centrifugation and filtration after culturing for t hours.

[0043] The results are as follows Figure 13 As shown in Table 1, the degradation rates of uric acid, triglycerides, and cholesterol by the Lactobacillus paracasei NEFU-5 reached 74.88%, 58.48%, and 41.6% respectively within 72 h.

[0044] Table 1

[0045] (2) In vivo test a) Establishment and grouping of animal models Sixty male C57BL / 6J mice weighing 17-22 g (purchased from Liaoning Changsheng Biotechnology Co., Ltd., license number SCXK(Liaoning) 2010-0001) were used to establish the Lactobacillus paracasei NEFU-5 group, HUA+HLP hyperuricemia group, hyperlipidemia group (HUA+HLP), and bacterial suspension treatment group (HB) by gavage. Specifically, starting from day 8, the mice were administered potassium oxonate + uric acid suspension at a dose of 300 mg / kg body weight by gavage daily, supplemented with a high-fat diet and free access to water. After 56 days of continuous feeding, blood was collected from each group of mice, and the serum was collected by centrifugation at 3000 r / min for 15 min.

[0046] b) Measurement of uric acid, triglycerides, and cholesterol levels On the last day of the 49-day continuous feeding following the above gavage, blood was collected from the orbital cavity of each group of mice. The blood was placed in the blood collection tube and left to stand at room temperature for 1 hour. The tube was then centrifuged at 3000 rpm and 4℃ for 15 minutes. The supernatant was collected and stored as serum. The levels of uric acid, triglycerides, and cholesterol in the mouse serum were measured using test kits provided by Nanjing Jiancheng Bioengineering Research Institute.

[0047] The results are shown in Tables 2-4. At 56 days (7 days of acclimatization feeding + 49 days of continuous feeding after gavage), the levels of serum uric acid, triglycerides, and cholesterol in the *Lactobacillus paracasei* NEFU-5 group (B) mice were significantly different from those in the model group (hyperuricemia + hyperlipidemia HUA + HLP) mice. This indicates that the *Lactobacillus paracasei* NEFU-5 group provided by this invention significantly reduced the levels of these three substances in serum compared to the model group (P < 0.0001).

[0048] Table 2

[0049] Table 3

[0050] Table 4

[0051] It is evident that the Lactobacillus paracasei strain NEFU-5 provided by this invention has a highly efficient and direct effect on degrading uric acid, triglycerides, and cholesterol in mice with hyperuricemia and hyperlipidemia.

[0052] c) Measurement of inflammatory factor levels The levels of IL-1β in the kidney and liver homogenates of mice in the above model group (HUA+HLP) and the Lactobacillus paracasei NEFU-5 treatment group (B) were detected using the ELISA kit from Seville Biosciences.

[0053] The results are as follows Figure 14-15 As shown, compared with the HUA hyperuricemia group (HUA), the IL-1β content in the kidney homogenate of mice in the Lactobacillus paracasei NEFU-5 treatment group (B) decreased from 3873.54 pg / mL to 2903.54 pg / mL (a decrease of ≈25%); the IL-1β content in the liver homogenate of mice decreased from 151.934 pg / mL to 80.772 pg / mL (a decrease of ≈47%), indicating that the Lactobacillus paracasei NEFU-5 provided by the present invention can effectively inhibit inflammatory pathways.

[0054] Example 2: Application of Lactobacillus paracasei NEFU-5 in the preparation of fermented products The strain *Lactobacillus paracasei* NEFU-5 obtained in Example 1 was inoculated into MRS liquid medium and cultured in an incubator at 37°C for 24 hours. Fresh, undamaged blueberries were washed, juiced, and sterilized (at 80°C for 20 min), then cooled to obtain juice. Under aseptic conditions, 2% of the cultured bacterial agent was added to the juice, stirred evenly, bottled, sealed, and fermented at 37°C for 36 hours. After fermentation, the juice was cooled at 4°C to obtain fermented blueberry juice.

[0055] The strain *Lactobacillus paracasei* NEFU-5 obtained in Example 1 was inoculated into MRS liquid medium and cultured in an incubator at 37°C for 24 hours. Fresh, undamaged oranges were washed, juiced, and sterilized (at 80°C for 20 minutes), then cooled to obtain juice. Under aseptic conditions, 2% of the cultured bacterial agent was added to the juice, stirred evenly, bottled, sealed, and fermented at 37°C for 36 hours. After fermentation, the juice was cooled at 4°C to obtain fermented orange juice.

[0056] The specific embodiments of the present invention disclosed above are merely illustrative of the invention. These embodiments do not exhaustively describe all details, nor do they limit the invention to the specific embodiments described. Many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A type of Lactobacillus paracasei NEFU-5, characterized in that, The Lactobacillus paracasei NEFU-5 ( Lactobacillus paracasei The accession number for NEFU-5 is CCTCC NO: M 2026147, and it is classified as follows: Lactobacillus paracasei NEFU-5 is deposited at the China Center for Type Culture Collection on January 16, 2026.

2. A microbial agent, characterized in that, The bacterial agent contains Lactobacillus paracasei NEFU-5 as described in claim 1.

3. The use of Lactobacillus paracasei NEFU-5 according to claim 1 or the bacterial agent according to claim 2 in the preparation of a drug, characterized in that, The drug has the following functions: degrading uric acid and relieving hyperuricemia; degrading triglycerides and cholesterol and relieving hyperlipidemia; and reducing inflammatory factors.

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