Lactobacillus paracasei for regulating local secretory immunoglobulin and systemic immunoglobulin of host to enhance anti-infection ability

Abstract

The invention discloses a Lactobacillus paracasei strain for regulating local secretory immune globulin and systemic immune globulin of a host to enhance infection resistance, and belongs to the technical field of microorganisms. The lactobacillus paracasei provided by the invention has the effects of reducing vaginal mucosa injury and inhibiting vagina inflammation, and the effects are specifically reflected as follows: (1) the expression of a polymeric immune globulin receptor gene of an organism is improved; (2) promoting the secretion of secretory immune globulin sIgA of the body; (3) promoting secretion of immune globulin IgG of the body; (4) reducing secretion of granulocyte colony stimulating factors of the body; (5) the secretion of TNF-alpha is inhibited, and the secretion of IL-10 is promoted; (6) improving pathological characterization of the organism; and (7) improving glycogen staining characterization after fungal infection of the organism. Therefore, the lactobacillus paracasei has a huge application prospect in products for improving vaginal mucosa injury and inhibiting vagina inflammation.

Description

Technical Field

[0001] The invention relates to a Lactobacillus paracasei strain capable of regulating local secretory immunoglobulin and systemic immunoglobulin of a host to enhance anti-infection ability, belonging to the technical field of microorganisms. Background Art

[0002] Candida albicans is a common opportunistic fungus found widely in the human mouth, intestines, and vagina. When the host immune system is suppressed or the bacterial flora is imbalanced, C. albicans can overgrow and cause local or systemic infections. Clinical treatment for C. albicans infections primarily relies on antifungal drugs. However, long-term use of antifungal drugs can cause vaginal microecological imbalance and mucosal barrier damage, leading to extremely high recurrence rates after discontinuation of medication. Furthermore, with long-term use of these drugs, fungal resistance increases significantly, making the treatment of candidal vaginitis even more difficult.

[0003] The host immune system plays a crucial role in defending against invading pathogens, particularly in local tissue defense, where immune responses are crucial for combating infection. Secretory immunoglobulin A (SIgA) is a key antibody in mucosal immunity, neutralizing toxins produced by pathogens and exerting anti-inflammatory effects. IgG also plays a crucial role in systemic immunity, recognizing and binding to specific antigens, thereby exerting its antibacterial, antiviral, and toxin-neutralizing properties. Compared to traditional direct antibacterial approaches, enhancing host immunity to prevent vaginal pathogen infection modulates the host's own immunity, enhancing its ability to recognize and eliminate pathogens, providing a long-lasting defense and significantly reducing recurrence. Prevention differs significantly from probiotic therapy in its mechanism of action. Treatment typically involves measures taken after a disease has already occurred, aiming to eliminate the pathogen and alleviate symptoms, while prevention involves measures taken before the disease develops to reduce the risk of infection.

[0004] However, the host possesses multiple anti-infective functions, and studies have shown that commensal bacteria can effectively activate host anti-infective pathways and regulate the production of antimicrobial substances to resist pathogenic bacteria. Andrew et al. proposed that repeated oral administration of commensal bacteria to mice could selectively induce IgA production in the mucosa and serum. Adriana et al. demonstrated that Bacteroides fragilis can promote type I interferon (IFN) signaling to maintain immune tolerance in mice. However, research on commensal bacteria regulating host immunity has primarily focused on the intestine, with less research on the vagina. Therefore, activating host anti-infective functions by vaginal commensal bacteria could maintain local microecological balance, reduce the incidence and recurrence of infection, and prevent the spread of infection at the source. This strategy not only mitigates the harm of infection to the host but also reduces reliance on traditional drug treatments, avoiding the development of drug resistance and side effects. Notably, there are significant differences between prevention and treatment in the management of Candida albicans infection. Treatment is typically initiated after infection has already occurred, aiming to eliminate existing pathogens and alleviate associated symptoms. However, therapeutic efficacy is often limited by factors such as pathogen resistance, infection site, and host immune status. In contrast, prevention aims to prevent infection by enhancing the host's immunity and reducing the chances of pathogen colonization. Davar compared the recurrence rate within 6 months in patients with vaginal candidiasis receiving preventive treatment with probiotics and placebo, and found that the recurrence rate in patients receiving probiotics was significantly lower than that in patients receiving placebo.

[0005] Therefore, regulating the host's local and systemic immunity through symbiotic bacteria to enhance the host's anti-infection ability and restore the vagina's natural defense mechanism are the most important strategies to resist the invasion of pathogens and prevent the aggravation of the disease. Summary of the Invention

[0006] In response to the above-mentioned deficiencies in the prior art, the present invention provides a strain of Lactobacillus paracasei that modulates the host's local secretory immunoglobulins and systemic immunoglobulins to enhance anti-infection ability. The purpose is to solve the technical problems of the prior art in preventing vaginal infections and reducing the occurrence and progression of diseases. The present invention aims to improve the host's immunity and ability to resist pathogenic bacteria infection, and to enhance the host's defense capabilities.

[0007] The first technical solution provided by the present invention is a strain of Lactobacillus paracasei CCFM1433, which was deposited in Guangdong Provincial Microbial Culture Collection Center on September 20, 2024, with a deposit number of GDMCC No: 65159. The Lactobacillus paracasei CCFM1433 was isolated from the vagina of a healthy woman.

[0008] The second technical solution provided by the present invention is a microbial preparation containing the Lactobacillus paracasei CCFM1433 described in the first technical solution.

[0009] In certain embodiments, the content of Lactobacillus paracasei CCFM1433 in the microbial preparation is not less than 1×10 6 CFU / mL or 1×10 6 CFU / g.

[0010] The third technical solution provided by the present invention is a product containing the Lactobacillus paracasei CCFM1433 described in the first technical solution or the microbial preparation described in the second technical solution.

[0011] In certain embodiments, the product is a food, a medicine, or a hygiene product.

[0012] Furthermore, the medicine comprises the above-mentioned strain and / or preparation, and a pharmaceutically acceptable carrier.

[0013] Furthermore, the carrier includes one or more of fillers, binders, wetting agents, disintegrants, lubricants, and flavoring agents commonly used in medicine.

[0014] Furthermore, the dosage form of the drug includes granules, capsules, tablets, pills, suppositories or oral liquids.

[0015] Furthermore, the medicines include oral tablets and capsules with enteric coatings, oral liquids; vaginal suppositories, tablets, gelatin capsules, sprays, creams, and gels.

[0016] Furthermore, the sanitary products include sanitary wet wipes, sanitary napkins, sanitary pads, sanitary tampons, sanitary napkins, vaginal washes, and women's antibacterial / antibacterial washes.

[0017] In certain embodiments, the content of Lactobacillus paracasei CCFM1433 in the product is not less than 1×10 6 CFU / mL or 1×10 6 CFU / g.

[0018] The fourth technical solution provided by the present invention is the use of the Lactobacillus paracasei CCFM1433 described in the first technical solution or the microbial preparation described in the second technical solution in the preparation of a product for enhancing vaginal immunity.

[0019] In certain embodiments, the effect of enhancing vaginal immunity includes increasing the secretion of secretory immunoglobulins sIgA and IgG, reducing the production of granulocyte colony-stimulating factor, inhibiting the secretion of TNF-α, increasing the secretion of IL-10 and improving the pathological characteristics of the body after infection.

[0020] In certain embodiments, the product is a medicine or a hygiene product.

[0021] Furthermore, the medicine comprises the above-mentioned strain and / or preparation, and a pharmaceutically acceptable carrier.

[0022] Furthermore, the carrier includes one or more of fillers, binders, wetting agents, disintegrants, lubricants, and flavoring agents commonly used in medicine.

[0023] Furthermore, the dosage form of the drug includes granules, capsules, tablets, pills, suppositories or oral liquids.

[0024] Furthermore, the medicines include oral tablets and capsules with enteric coatings, oral liquids; vaginal suppositories, tablets, gelatin capsules, sprays, creams, and gels.

[0025] Furthermore, the sanitary products include sanitary wet wipes, sanitary napkins, sanitary pads, sanitary tampons, sanitary napkins, vaginal washes, and women's antibacterial / antibacterial washes.

[0026] The fifth technical solution provided by the present invention is the use of the Lactobacillus paracasei CCFM1433 described in the first technical solution or the microbial preparation described in the second technical solution in the preparation of a product for preventing vaginal pathogenic bacteria infection.

[0027] In certain embodiments, the effects of the product include reducing TNF-α and increasing IL-10 secretion in mouse spleen tissue.

[0028] In certain embodiments, the product is a medicine or a hygiene product.

[0029] Furthermore, the medicine comprises the above-mentioned strain and / or preparation, and a pharmaceutically acceptable carrier.

[0030] Furthermore, the carrier includes one or more of fillers, binders, wetting agents, disintegrants, lubricants, and flavoring agents commonly used in medicine.

[0031] Furthermore, the dosage form of the drug includes granules, capsules, tablets, pills, suppositories or oral liquids.

[0032] Furthermore, the medicines include oral tablets and capsules with enteric coatings, oral liquids; vaginal suppositories, tablets, gelatin capsules, sprays, creams, and gels.

[0033] Furthermore, the sanitary products include sanitary wet wipes, sanitary napkins, sanitary pads, sanitary tampons, sanitary napkins, vaginal washes, and women's antibacterial / antibacterial washes.

[0034] Beneficial effects:

[0035] The present invention provides a strain of Lacticaseibacillus paracasei CCFM1433, isolated from the vagina of a healthy woman, which has the effects of enhancing the vagina's ability to resist infection, strengthening the host's immune defense, and inhibiting vaginal inflammation, specifically manifested as follows: (1) increasing the expression of the body's polymeric immunoglobulin receptor gene; (2) promoting the body's secretion of secretory immunoglobulin sIgA; (3) promoting the body's secretion of immunoglobulin IgG; (4) reducing the body's secretion of granulocyte colony-stimulating factor; (5) inhibiting the secretion of TNF-α and increasing the secretion of IL-10; (6) improving vaginal pathological manifestations; and (7) improving the body's glycogen staining manifestations after fungal infection. Therefore, the Lacticaseibacillus paracasei has great application prospects in products for enhancing local immunity and regulating vaginal inflammation.

[0036] Biomaterial Deposit

[0037] The Lacticaseibacillus paracasei CCFM1433 provided by the present invention was deposited in the Guangdong Provincial Microbial Culture Collection Center on September 20, 2024, with a deposit number of GDMCC No: 65159, and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : Streak results of Lactobacillus paracasei CCFM1433.

[0039] Figure 2 : Flowchart of animal experiments.

[0040] Figure 3 :The effect of Lactobacillus paracasei on the gene expression of polymeric immunoglobulin receptor pIgR in animals.

[0041] Figure 4 :The effect of Lactobacillus paracasei on the secretion of secretory immunoglobulin sIgA in animals.

[0042] Figure 5 : Diagram of the effect of Lactobacillus paracasei on the secretion of immunoglobulin IgG in animals.

[0043] Figure 6 :The effect of Lactobacillus paracasei on the secretion of granulocyte colony-stimulating factor in animals.

[0044] Figure 7 :The effect of Lactobacillus paracasei on the expression of animal cytokines TNF-α and IL-10.

[0045] Figure 8 : Figure 3 histopathological evaluation of mouse vagina.

[0046] Figure 9 : Periodic acid-Schiff staining of mouse vaginal tissue.

[0047] (Different lowercase letters in the figure indicate significant differences among the groups, p < 0.05). DETAILED DESCRIPTION

[0048] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0049] The culture medium involved in the following examples is as follows:

[0050] LBS solid medium ( / L): 5 g tryptone, 5 g yeast extract powder, 6 g potassium dihydrogen phosphate, 0.034 g potassium dihydrogen phosphate, 0.575 g magnesium sulfate, 20 g glucose, 25 g sodium acetate, 2 g ammonium citrate, 0.12 g manganese sulfate, 15 g agar, 1 mL Tween-80, 1.3 mL glacial acetic acid, pH 5.3-5.7.

[0051] MRS solid medium ( / L): 5 g peptone, 5 g yeast extract powder, 15 g glucose, 3 g disodium hydrogen phosphate, 1 mL Tween-80, 3 g dipotassium hydrogen phosphate, 3 g diammonium hydrogen citrate, 0.1 g magnesium sulfate heptahydrate, 0.05 g manganese sulfate monohydrate, 20 g agar, pH 6.2-6.4.

[0052] MRS liquid medium ( / L): 5 g peptone, 5 g yeast extract powder, 15 g glucose, 3 g disodium hydrogen phosphate, 1 mL Tween-80, 3 g dipotassium hydrogen phosphate, 3 g diammonium hydrogen citrate, 0.1 g magnesium sulfate heptahydrate, 0.05 g manganese sulfate monohydrate, pH 6.2-6.4.

[0053] SDA medium ( / L): animal tissue pepsin hydrolysate and trypticase 10g, glucose 40g, agar 15g, pH 5.6±0.2.

[0054] SDB medium ( / L): animal tissue pepsin hydrolysate and trypsin casein 10g, glucose 20g, pH 5.6±0.2.

[0055] The strains and animals involved in the following examples are as follows:

[0056] The bacterial culture of Lactobacillus paracasei CCFM1433 was isolated from female vagina and stored in the bacterial strain bank of Food Biotechnology Center of Jiangnan University.

[0057] Lactobacillus delbrueckii DM8909 was isolated from Dingjunsheng Lactobacillus live vaginal capsules and stored in the strain bank of Food Biotechnology Center of Jiangnan University.

[0058] Candida albicans SC5314 was purchased from Guangdong Institute of Microbiology Culture Collection Center (GDMCC).

[0059] 7-week-old SPF female BALB / c mice, weighing 18-20 g, were purchased from Beijing Weitonglihua Laboratory Animal Technology Co., Ltd. (production license number SCXK (Beijing) 2012-0001).

[0060] The bacterial solution preparation method involved in the following examples is as follows:

[0061] Lactobacillus paracasei CCFM1433 bacterial culture: Lactobacillus paracasei CCFM1433 was streaked and isolated on MRS solid medium, cultured in an anaerobic incubator at 37°C for 36 h, single colonies were picked and placed in 5 mL of MRS liquid medium, cultured in an anaerobic incubator at 37°C for 20 h, and inoculated into 1 L of culture system at a 4% inoculum size. After culture in an incubator at 37°C for 20 h, the bacterial sludge was centrifuged and the bacterial solution concentration was adjusted to 5×10 9 CFU / mL. The preparation method of Lactobacillus delbrueckii DM8909 bacterial solution is the same as above, and it is recorded as DM8909.

[0062] Candida albicans suspension: SC5314 was streaked on SDA medium and cultured in a 28°C incubator for 48 h. A single colony was picked and inoculated into SDB medium for expansion. The final concentration of the bacterial suspension was adjusted to 5 × 10 8 CFU / mL.

[0063] Estradiol: Dissolve 0.1 mg of β-estradiol in 0.05 mL of sesame oil and prepare it for use immediately.

[0064] Example 1 Isolation and identification of Lactobacillus paracasei CCFM1433

[0065] Vaginal swab samples were collected from healthy women and placed in an EP tube containing 1 mL of sterile saline. 0.2 mL was drawn into 1.8 mL of sterile saline to obtain 10 -1 Dilution, then draw 0.5mL 10 -1 Dilute in 4.5 mL of saline to obtain 10 -2 Dilution, follow this operation to obtain 10 -3 , 10 -4 , 10 -5 , 10 -6 Gradient dilution. Take 10 -4 , 10 -5 , 10 -6 Place 1 mL of each dilution in a dish, pour into MRS solid culture medium, mix gently, wait for the culture medium to solidify, and culture inverted at 37°C for 48 h.

[0066] Select colonies of different morphologies and perform streak purification on MRS plates ( Figure 1 ), pick a purified single colony and inoculate it into 5 mL of liquid culture medium, and culture at 37°C for 48 hours. Take 1.5 mL of the cultured bacterial suspension, centrifuge at 6000 rpm for 3 minutes, discard the supernatant, wash three times with 1.5 mL of sterile water, and resuspend in 1.5 mL of sterile water to use as a template for bacterial identification. Set up a 20 μL PCR system, add 0.5 μL of forward primer (10 μM), 0.5 μL of reverse primer (10 μM), 10 μL of 2× Taq Mixture, 0.5 μL of bacterial suspension, and 8.5 μL of double-distilled water. Primer information is shown in Table 1.

[0067] Table 1: Primer information

[0068]

[0069] PCR conditions: 95°C for 5 minutes, 95°C for 10 seconds, 55°C for 30 seconds, 72°C for 30 seconds, steps 2-4 at 30×, 72°C for 5 minutes, and 12°C for 2 minutes. The resulting PCR product was sent to a professional sequencing company. The sequencing results were compared with a BLAST search and similarity comparison in GeneBank, and the strain was identified as Lacticaseibacillus paracasei.

[0070] For correctly identified bacterial strains, 1.5 mL of bacterial solution was transferred to a 2 mL bacterial culture storage tube. After centrifugation at 6000 rpm for 3 min, the supernatant was removed in a laminar flow hood, 1 mL of 30% sterile glycerol was added, and the mixture was thoroughly mixed using a vortex oscillator before storage in a -80°C refrigerator.

[0071] 16S sequence information (SEQ ID No. 1):

[0072]

[0073] Example 2 Application of Lactobacillus paracasei CCFM1433 in Improving the Resistance of Mice to Pathogenic Bacteria Infection

[0074] Twenty 7-week-old SPF female BALB / c mice weighing 18-20 g were randomly divided into 4 cages with 5 mice in each cage. Figure 2 Flowchart of animal experiments.

[0075] Table 2: Animal experimental plan and grouping

[0076]

[0077] The mice were randomly divided into 4 groups according to their body weight. The specific group information is shown in Table 2. All mice in the groups were kept normally during the whole experiment. The blank group and the model group were gavaged with 200 μL normal saline for 17 consecutive days, and the experimental group was gavaged with 200 μL of 5×10 9 CFU / mL of Lactobacillus delbrueckii DM8909 or Lactobacillus paracasei CCFM1433. On days 12-15, the blank group was subcutaneously injected with 50 μL of normal saline, and the model group and experimental group were subcutaneously injected with 50 μL of estradiol to induce estrus (subcutaneous injection on days 12 and 15). On days 16-17, the model group and experimental group used a pipette to draw 20 μL of 5×10 8 A suspension of C. albicans (CFU / mL) was slowly injected into the vagina of mice, which were then held in an inverted position for 1-2 minutes. A control group was inoculated with normal saline once daily. On day 18, all mice were sacrificed, serum was isolated, and vaginal tissue was removed for analysis of polymeric immunoglobulin receptor gene expression, immunoglobulin secretion levels, TNF-α, IL-10, and G-CSF levels, and subsequent histopathological staining.

[0078] Assay Methods: At the end of the experiment, mice were sacrificed and vaginal tissue was dissected. A portion of the tissue was homogenized using pre-chilled RIPA lysis buffer (Biyuntian Biotechnology Co., Ltd.) and a protease inhibitor cocktail. The sample was centrifuged at 12,000 rpm for 15 minutes at 4°C. The vaginal tissue supernatant was then assayed for pIgR, sIgA, TNF-α, and IL-10 levels according to the kit instructions (Nanjing Senbeijia Biotechnology Co., Ltd.). Another portion of the vaginal tissue was placed in 4% paraformaldehyde solution for histopathological examination.

[0079] Histopathological Observation: Vaginal tissue was fixed with 4% paraformaldehyde, embedded in paraffin, and sectioned into 5-mm-thick sections. Hematoxylin and eosin (H&E) and periodic acid-Schiff staining were performed. Vaginal tissue samples were examined at 20x magnification using a pathology slide scanner (PanoramicMIDI, 3DHistech Ltd, Budapest, Hungary).

[0080] Experimental results:

[0081] (1) Polymeric immunoglobulin receptor pIgR

[0082] pIgR (Polymeric Immunoglobulin Receptor) is a transmembrane protein primarily expressed on the surface of epithelial cells. Its primary function is to mediate the transport of secretory immunoglobulins (such as IgA) and participate in mucosal immune responses.

[0083] Table 3: Primers

[0084]

[0085] like Figure 3 As shown in the results, compared with the blank group (promoting human pIgR expression to 1.07), the relative expression of pIgR mRNA in the model group was significantly reduced to 0.43. Oral administration of Lactobacillus delbrueckii DM8909 promoted human pIgR expression to 0.8 (increased to 186.0%), and Lactobacillus paracasei CCFM1433 promoted human pIgR expression to 0.84 (increased to 195.3%). Probiotics can effectively increase the relative expression of pIgR mRNA (p>0.05), and Lactobacillus paracasei CCFM1433 has a more significant effect in increasing the relative expression of pIgR mRNA.

[0086] (2) Secretory immunoglobulin receptor sIgA

[0087] Secretory immunoglobulin A (sIgA) is an antibody that plays a key role in mucosal immunity. The production of sIgA involves B cells in mucosa-associated lymphoid tissues. These cells differentiate into plasma cells in response to antigen stimulation and secrete polymeric IgA (pIgA). pIgA is transported across mucosal epithelial cells via the polymeric immunoglobulin receptor (pIgR), ultimately forming sIgA and releasing it onto the mucosal surface. sIgA can prevent pathogen adhesion and exert an immune clearance effect.

[0088] like Figure 4As shown, compared with the blank group (0.84 μg / mL), the content of sIgA produced by the body in the model group after intervention was significantly reduced to 0.47 μg / mL. After oral administration of Lactobacillus delbrueckii DM8909, the body produced sIgA of 0.66 μg / mL (increased by 140.4%), which was significantly different from the model group. After intervention with Lactobacillus paracasei CCFM1433, the body produced sIgA of 0.72 μg / mL (increased by 153.2%), which was significantly different from the model group before, and the level of sIgA was higher, close to that of the blank group. Therefore, Lactobacillus paracasei CCFM1433 has a good ability to promote the secretion of sIgA.

[0089] (3) Immunoglobulin IgG

[0090] Immunoglobulin G (IgG) is the most prevalent antibody type in human serum, accounting for approximately 75% of total immunoglobulins. IgG can recognize and bind to specific antigens, such as bacteria and viruses, thereby neutralizing them and is a key antibody in the body's fight against infection.

[0091] like Figure 5 As shown, compared with the blank group (7.17 μg / mL), the IgG content produced by the body in the model group was significantly reduced after intervention, which was 6.23 μg / mL. After oral administration of Lactobacillus delbrueckii DM8909, the IgG produced by the body was 6.53 μg / mL (increased to 104.8%), but there was no significant difference compared with the model group; after intervention with Lactobacillus paracasei CCFM1433, the IgG content produced by the body was 7.01 μg / mL (increased to 112.5%). There was a significant difference in the IgG level between Lactobacillus paracasei CCFM1433 and the model group (p>0.05), and the effect was better, indicating that Lactobacillus paracasei CCFM1433 can significantly enhance the host systemic immunity to resist pathogenic bacteria infection.

[0092] (4) Granulocyte colony-stimulating factor (G-CSF)

[0093] Granulocyte colony-stimulating factor (G-CSF) is a proinflammatory cytokine whose main function is to promote the survival, proliferation, differentiation and function of neutrophil progenitors and mature neutrophils.

[0094] like Figure 6As shown, compared with the blank group (364.07 ng / L), the content of G-CSF produced by the body in the model group after intervention was significantly increased to 419.63 ng / L. After oral Lactobacillus delbrueckii DM8909 intervention, the body produced 372.72 ng / L of G-CSF (a decrease of 11.2% compared with the model group), and after intervention with Lactobacillus paracasei CCFM1433, the body produced 350.49 ng / L of G-CSF (a decrease of 16.5% compared with the model group). Both can significantly reduce the level of G-CSF, and Lactobacillus paracasei CCFM1433 has a more significant effect in reducing G-CSF, allowing the body to tend to normalize the level and thus resist a series of inflammations caused by pathogenic bacteria infection.

[0095] (5) Secretion of tumor necrosis factor-α (TNF-α) and interleukin IL-10 in mouse spleen tissue

[0096] TNF-α plays a promoting role in inflammatory response and is a small molecule protein mainly secreted by monocytes and macrophages; IL-10 is a multi-functional cytokine with strong anti-inflammatory properties, which is mainly secreted by activated T cells, monocytes, B cells and macrophages.

[0097] like Figure 7 As shown in (A), the TNF-α content in the blank control group was 243.70 ng / L, and that in the model group was 408.91 ng / L. Compared with the model group, the TNF-α production in the body after oral administration of live bacteria of Lactobacillus delbrueckii DM8909 was 352.93 ng / L (a decrease of 13.7% compared with the model group), and the TNF-α production in the body after oral administration of live bacteria of Lactobacillus paracasei CCFM1433 was 325.76 ng / L (a decrease of 20.3% compared with the model group). Both groups were able to significantly reduce the TNF-α level compared with the model group, but Lactobacillus paracasei CCFM1433 was better than the Lactobacillus delbrueckii DM8909 group in reducing the TNF-α level.

[0098] like Figure 7 As shown in (B), the IL-10 secretion of the blank control group was 572.42 pg / mL, and the IL-10 secretion of the model group was 413.82 pg / mL. Compared with the model group, the IL-10 secretion of oral Lactobacillus delbrueckii DM8909 was 497.77 pg / mL (increased to 120.3%), and the IL-10 secretion of oral Lactobacillus paracasei CCFM1433 was 512.82 pg / mL (increased to 123.9%). Compared with the model group, both groups were able to significantly increase the IL-10 level. The ability of the Lactobacillus paracasei CCFM1433 group to increase IL-10 was significantly better than that of the Lactobacillus delbrueckii DM8909 group.

[0099] In summary, Lactobacillus paracasei CCFM1433 can significantly reduce TNF-α and increase IL-10 secretion in vaginal tissue of mice, inhibit further development of inflammation, and accelerate the body's immune regulation.

[0100] (6) Mouse vaginal histopathological analysis

[0101] HE staining, or hematoxylin-eosin staining, is the most commonly used staining technique in histopathology and histology. This staining method clearly displays the morphological structure of cells and tissues and is fundamental to disease diagnosis and research.

[0102] like Figure 8 As shown, in the blank control group, the vaginal epithelium of mice was smooth and continuous, with intact tissue structure and no obvious inflammatory cell infiltration. In the model group, the vaginal epithelium showed poor continuity, with surface cell erosion, submucosal interstitial congestion, and a large number of inflammatory cells infiltrating both the epithelium and interstitium. The Lactobacillus delbrueckii DM8909 group showed less inflammatory cell infiltration than the model group, but there was significant squamous epithelial hyperplasia and slight damage to the vaginal tissue surface. In mice infected with Lactobacillus paracasei CCFM1433, epithelial damage was less severe, inflammatory cells were significantly reduced, and the cornified layer reappeared on the mucosal surface. Lactobacillus paracasei CCFM1433 helped repair the vaginal mucosa, and the extent of vaginal tissue damage in mice treated with CCFM1433 was less than that in the Lactobacillus delbrueckii DM8909 group.

[0103] (7) Periodic acid-Schiff staining analysis of mouse vaginal tissue

[0104] Periodic acid-Schiff (PAS) staining is a commonly used histochemical staining technique, primarily used to visualize polysaccharides in tissues, such as glycogen, mucopolysaccharides, and fungi. In PAS staining, polysaccharides appear purple or magenta, while cell nuclei are stained blue by hematoxylin.

[0105] like Figure 9As shown, PAS staining of vaginal tissue from mice in the normal group exhibited a uniform purple-red color, reflecting normal distribution of glycogen within vaginal epithelial cells and indicative of mucosal health. Purple-red fungal spore-like structures were observed within the vaginal epithelial cells of mice in the model group, indicating fungal invasion. In contrast, mice orally administered with live Lactobacillus delbrueckii DM8909 and Lactobacillus paracasei CCFM1433 bacteria showed a significant decrease in surface glycogen content in vaginal tissue, along with a significant reduction in fungal invasion. This suggests that probiotic intervention has a positive effect against Candida albicans infection and enhances host defense mechanisms. However, a small amount of glycogen aggregated on the surface of CCFM1433 bacteria suggests that, after infection, CCFM1433 bacteria modulates host resistance and enhances host defenses. However, oral administration of Lactobacillus delbrueckii DM8909 resulted in a loss of surface glycogen in vaginal tissue, and the mucosa was slightly damaged. Therefore, CCFM1433 bacteria can enhance host defenses and reduce fungal invasion, thereby playing a positive role in preventing candidal vaginitis.

[0106] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. The present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A strain of Lactobacillus paracasei CCFM1433, which was deposited in Guangdong Provincial Microbial Culture Collection Center on September 20, 2024, with a deposit number of GDMCCNo:65159.

2. a microbial preparation comprising the lactobacillus paracasei CCFM1433 of claim 1.

3. The microbial preparation according to claim 2, characterized in that The content of Lactobacillus paracasei CCFM1433 in the microbial preparation is not less than 1×10 6 CFU / mL or 1×10 6 CFU / g.

4. A product containing the Lactobacillus paracasei CCFM1433 of claim 1 or the microbial preparation of claim 2 or 3.

5. The product according to claim 4, characterized in that The product is food, medicine or sanitary product.

6. The product according to claim 4, characterized in that The content of Lactobacillus paracasei CCFM1433 in the product is not less than 1×10 6 CFU / mL or 1×10 6 CFU / g.

7. Use of the Lactobacillus paracasei CCFM1433 according to claim 1 or the microbial preparation according to claim 2 or 3 in preparing a product for enhancing vaginal immunity, characterized in that: The enhancement of vaginal immunity includes at least one of the following functions: (1) Increase the expression of polymeric immunoglobulin receptor genes; (2) Promote the secretion of local secretory immunoglobulin sIgA in the vagina; (3) Promote the secretion of immunoglobulin IgG; (4) Reduce the body's secretion of granulocyte colony-stimulating factor G-CSF; (5) Inhibit the secretion of TNF-α and increase the secretion of IL-10; (6) Improve vaginal pathological manifestations; (7) Improve glycogen staining after fungal infection.

8. The use according to claim 7, characterized in that The product is a medicine or a sanitary product; preferably, the sanitary product includes sanitary wet wipes, sanitary napkins, sanitary pads, sanitary tampons, sanitary napkins, vaginal washes, women's antibacterial washes or antibacterial washes.

9. Use of the Lactobacillus paracasei CCFM1433 according to claim 1 or the microbial preparation according to claim 2 or 3 in preparing a product for preventing vaginal pathogen infection.

10. The use according to claim 9, characterized in that The pathogenic bacteria include but are not limited to Candida albicans; the product is a medicine or a sanitary product; preferably, the sanitary product includes sanitary wet wipes, sanitary napkins, sanitary pads, sanitary tampons, sanitary napkins, vaginal washes, women's antibacterial washes or antibacterial washes.

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