Immune reaction regulation and control metagen preparation and preparation method and application thereof

Abstract

The invention discloses a postbiotic preparation for regulating and controlling immune response as well as a preparation method and application thereof, and the postbiotic preparation for regulating and controlling immune response is composed of an animal bifidobacterium subsp. Lactis BLa36 strain and an animal bifidobacterium subsp. Lactis BLa80; wherein the ratio of the viable count of the animal bifidobacterium subsp. Lactis BLa36 strain to the viable count of the animal bifidobacterium subsp. Lactis BLa80 strain is (1-10): (1-10). The method has a huge application prospect in products for improving and repairing immune disorder and inflammatory injury problems caused by allergy.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and in particular relates to a postbiotic preparation for regulating immune response, and a preparation method and application thereof. Background Art

[0002] When an individual is exposed to foreign antigens, they are captured and processed by dendritic cells (DCs) in the immune system, and then presented to naive T cells, which differentiate into type 2 helper T cells (Th2 cells), secrete cytokines such as IL-4 and IL-13, and stimulate B cells to produce specific IgE antibodies. These IgE antibodies bind to the high-affinity IgE receptors (FcεRI) on the surface of mast cells and basophils. Repeated stimulation triggers these cells to release inflammatory mediators such as histamine, leukotrienes, and prostaglandin D2. This excessive immunity causes immune system disorders, causing symptoms such as skin itching, respiratory symptoms, and gastrointestinal discomfort.

[0003] At present, the drugs used to treat diseases caused by excessive release of inflammatory mediators include antihistamines, glucocorticoids, and anti-leukotrienes. However, these drugs can relieve symptoms, but usually cannot correct the underlying immune disorder, so they cannot completely cure allergies, and may have side effects, such as the potential toxicity of loratadine to the cardiovascular system. Studies have found that postbiotics can activate related signaling pathways, exert immunomodulatory effects through multiple mechanisms, enhance the body's anti-inflammatory activity, and thus help regulate inflammatory symptoms. For example, a study compared the effects of adding live or inactivated Lactobacillus rhamnosus GG to deep hydrolyzed whey formula products on infant eczema. The results showed that formula products with inactivated Lactobacillus rhamnosus GG can improve infant skin inflammation.

[0004] Probiotics have been widely studied and used in foods and supplements because of their multiple benefits to host health, including their immunomodulatory properties. At the same time, postbiotics, as a new direction in probiotic research, have significant advantages. Postbiotics are inanimate microorganisms and / or their component preparations that are beneficial to host health, with the advantages of safety, stability, easy storage and production, and clear chemical structure. Compared with probiotics, postbiotics are safer, more stable, more effective and more convenient. However, there are few reports on the regulatory effects of postbiotic preparations on the immune system, and the mechanism by which the active ingredients in postbiotics regulate immunity is still unclear. Therefore, it is of great significance to develop a postbiotic preparation with immune regulatory function. Summary of the invention

[0005] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0006] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0007] Therefore, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a postbiotic preparation for regulating immune response.

[0008] In order to solve the above technical problems, the present invention provides the following technical solutions: a postbiotic preparation for regulating immune response, characterized in that: the postbiotic preparation for regulating immune response is composed of Bifidobacterium animalis subsp. Lactis BLa36 strain and Bifidobacterium animalis subsp. Lactis BLa80 strain;

[0009] Wherein, the ratio of the number of live bacteria of Bifidobacterium animalis subsp. Lactis BLa36 strain to that of Bifidobacterium animalis subsp. Lactis BLa80 strain is 1-10:1-10.

[0010] As a preferred embodiment of the postbiotic preparation of the present invention, the total number of viable bacteria in the postbiotic preparation is not less than 1×10 9 CFU / mL.

[0011] As a preferred embodiment of the postbiotic preparation described in the present invention, wherein: the Bifidobacterium animalis subsp. Lactis BLa36 strain is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 24029, a deposit date of December 2, 2021, and a deposit address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the Bifidobacterium animalis subsp. Lactis BLa80 strain is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 22547, a deposit date of May 17, 2021, and a deposit address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

[0012] Another object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a postbiotic preparation for regulating immune response, which is characterized by comprising: inoculating Bifidobacterium animalissubsp.Lactis BLa36 strain and Bifidobacterium animalissubsp.LactisBLa80 in MRS liquid culture medium for cultivation, centrifuging to obtain bacterial bodies, adjusting the bacterial concentration with PBS, high-pressure homogenization, centrifuging, filtering, and then mixing.

[0013] As a preferred embodiment of the preparation method of the present invention, the culture temperature is 37° C. and the culture time is 12 to 18 hours.

[0014] As a preferred embodiment of the preparation method of the present invention, the high pressure homogenization temperature is 4-10°C, the pressure is 250-310 MPa, and the number of times is 8-10 times.

[0015] Another object of the present invention is to overcome the deficiencies in the prior art and provide an application of a postbiotic preparation for regulating immune response, characterized in that the postbiotic preparation alleviates the decline in cell viability, IgE receptor activation, and excessive secretion of histamine, β-hexosaminidase, and inflammatory factors caused by immune disorders.

[0016] As a preferred embodiment of the application of the present invention, the postbiotic preparation enhances the viability of RBL-2H3 cells and inhibits the transcriptional expression of the IgE affinity receptor FcεRI.

[0017] As a preferred embodiment of the application of the present invention, the postbiotic preparation weakens the release of histamine, a key factor in allergies, and downregulates the release rate of β-hexosaminidase, a marker of mast cell degranulation.

[0018] As a preferred embodiment of the application of the present invention, the postbiotic preparation reduces the level of inflammatory factor IL-4.

[0019] Beneficial effects of the present invention:

[0020] The present invention can synergistically enhance the effect after compounding Bifidobacterium animalis subsp. Lactis Bla36 and Bifidobacterium animalis subsp. Lactis Bla80, improve the viability of RBL-2H3 cells, inhibit the transcriptional expression of IgE affinity receptor FcεRI, weaken the release of histamine, a key factor of allergy, down-regulate the release rate of mast cell degranulation marker β-hexosaminidase, and reduce the level of inflammatory factor IL-4. It has great application prospects in products that improve and repair immune disorders and inflammatory damage caused by allergies. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0022] Figure 1 This is a graph showing the effects of different postbiotics on RBL-2H3 cell viability in the present invention.

[0023] Figure 2 This is a graph showing the effects of different postbiotics of the present invention on the expression of FcεRI receptor in RBL-2H3 cells.

[0024] Figure 3 This is a graph showing the effects of different postbiotics of the present invention on the histamine secretion level of RBL-2H3 cells.

[0025] Figure 4 This is a graph showing the effects of different postbiotics of the present invention on the release rate of β-hexosaminidase in RBL-2H3 cells.

[0026] Figure 5 This is a graph showing the effects of different postbiotics of the present invention on the secretion level of inflammatory factor IL-4 in RBL-2H3 cells. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0030] Unless otherwise specified, all raw materials used in the examples of the present invention are commercially available, as shown in Table 1 for details.

[0031] Table 1

[0032] name Commercial channels Part Number MRS culture medium components and reagents China National Pharmaceutical Group Corporation CCK-8 MedChemexpress Biotech HY-K0301 Trypsin-EDTA (0.25%) MedChemexpress Biotech HY-K3007 Reverse transcription kit MedChemexpress Biotech HY-K0510A SYBR Green qPCR Master Mix MedChemexpress Biotech HY-K0501A Histamine MedChemexpress Biotech HY-B1204 Anti-DNP-IgE monoclonal antibody Merck Chemical Technology (Shanghai) Co., Ltd. D8406 DNP-HSA Merck Chemical Technology (Shanghai) Co., Ltd. A6661 DMEM medium Thermo Fisher Scientific (China) Co., Ltd. 10566016 Fetal bovine serum Thermo Fisher Scientific (China) Co., Ltd. 11995065 Trizol Thermo Fisher Scientific (China) Co., Ltd. 15596026CN

[0033] The present invention provides a postbiotic preparation for improving immune disorders. The postbiotics used are derived from comparative strains, including Bifidobacterium animalis subsp. Lactis BLa36 strain, the preservation unit of which is the General Microbiology Center of China National Microbiological Culture Collection Administration, the preservation number is CGMCC No. 24029, the preservation date is December 2, 2021, and the preservation address is No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing. It was first disclosed in Chinese patent CN202210261807.5. Bifidobacterium animalis subsp. Lactis BLa80 is deposited in the General Microbiology Center of China National Microbiological Culture Collection Administration, with a deposit number of CGMCC No. 22547, a deposit date of May 17, 2021, and a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. It was first disclosed in Chinese patent CN202110864979.7. Lactobacillus casei LC89 is deposited in the General Microbiology Center of China National Microbiological Culture Collection Administration, with a deposit number of CGMCC NO. 15409, a deposit date of March 5, 2018, and a deposit address of No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. It was first disclosed in Chinese patent CN201911054563.8 (the strain used in this patent is provided by Weikang Probiotics (Suzhou) Co., Ltd.).

[0034] The rat basophilic leukemia cells (RBL-2H3) used in the experiment were purchased from the Cell Bank of Type Culture Collection Committee of the Chinese Academy of Sciences.

[0035] MRS solid medium ( / L): Weigh 10 g of peptone, 10 g of beef extract, 20 g of glucose, 2 g of sodium acetate, 5 g of yeast powder, 2 g of diammonium hydrogen citrate, 2.6 g of K2PO4·3H2O, 0.1 g of MgSO4·7H2O, 0.05 g of MnSO4, 20 g of agar, and 1 g of L-cysteine, dissolve them in deionized water, add 1 mL of Tween 80, sterilize and cool, and pour into a sterile culture dish for later use.

[0036] MRS liquid medium ( / L): Weigh 10 g of peptone, 10 g of beef extract, 20 g of glucose, 2 g of sodium acetate, 5 g of yeast powder, 2 g of diammonium hydrogen citrate, 2.6 g of K2PO4·3H2O, 0.1 g of MgSO4·7H2O, 0.05 g of MnSO4 and 1 g of L-cysteine, dissolve them in deionized water, add 1 mL of Tween 80, sterilize and cool for later use.

[0037] Color developer ( / L): 12.17 g citric acid, 15.49 g sodium citrate, 0.342 g 4-nitrobenzene-N-acetyl-β-D-aminoglucosidoside. Prepare with pure water, filter with a 0.22 μm pore size filter membrane, and store at -20°C.

[0038] Stop solution ( / L): 10.73 g sodium carbonate, 8.4 g sodium bicarbonate.

[0039] Example 1

[0040] In this example, the postbiotic sample was prepared after culturing Bifidobacterium animalis subspecies BLa36, Bifidobacterium animalis subspecies BLa80 and Lactobacillus casei LC89, and the steps were as follows:

[0041] The strain was inoculated into MRS liquid medium, cultured at 37°C for 12-18h, centrifuged at 8000rpm for 10min, the supernatant was removed, the bacteria were collected, and the bacterial concentration was adjusted to 10 with PBS. 9 CFU / mL, high-pressure homogenization at 250-310MPa pressure, 4-10℃ for 8-10 times, centrifugation at 8000rpm for 10min, the supernatant was filtered with a 0.22μm filter membrane and stored at -20℃.

[0042] Example 2

[0043] The alleviating effect of postbiotic samples on cell allergy models:

[0044] The frozen RBL-2H3 cells were quickly thawed at 37°C, and the cells were resuspended in three volumes of cell culture medium. Centrifuged at 500g for 5 minutes, the supernatant was discarded, the cells were resuspended in cell culture medium again, and inoculated into a T25 cell culture dish.

[0045] The revived cells were cultured under 5% CO2 and 37°C. When about 80% of the area of ​​the cell culture dish was covered by growing cells, the cells were subcultured. Digested with 1 mL of trypsin-EDTA (0.25%), observed under a microscope, and when the cells were suspended, digestion was immediately terminated with 3 volumes of complete cell culture medium. After centrifugation, the cells were collected and subcultured at a ratio of 1:3.

[0046] After three passages, the cell concentration was adjusted to 4.6 × 10 5 / mL, 100μL of cell suspension was inoculated in each well of a 96-well plate, and 1.5mL of cell suspension was inoculated in each well of a 12-well plate. After the cells adhered to the wall, a blank group, a model group, a Yang Shen group, a Yin Shen group, a single postbiotic group and a postbiotic compound group were set up. The specific grouping information is shown in Table 2. In the table, the Yang Shen group is loratadine (Loratadine) and the Yin Shen group is phosphate buffer PBS. After sensitizing the groups except the blank group with 200ng / mL anti-DNP-IgE overnight, the postbiotic samples were diluted 40 times with cell culture medium and co-cultured with cells for 1.5h. After 1.5h, the supernatant was discarded and washed 3 times with PBS. The DNP-HAS action concentration was 1000ng / mL for 1h.

[0047] Table 2 Grouping information table

[0048]

[0049]

[0050] (1) Effects of postbiotic samples on cell viability

[0051] After 1 hour of excitation, 6 replicates were set for each concentration in each group of 96-well plates, and 10 μL of CCK-8 solution was added, mixed and incubated at 37°C for 2 hours. Then, the absorbance value (OD) at 450 nm was measured with an ELISA reader, and the cell viability was calculated, cell viability (%) = (experimental group OD-blank well OD) / (control group OD-blank well OD) × 100%.

[0052] Cell viability and function play a vital role in the occurrence, development and regulation of allergic reactions. The detection of cell viability can reflect the state of cells to a certain extent. Figure 1As shown in the figure, compared with the blank group, the cell viability of the model group decreased by 35.64% (P<0.0001), which indicates that the cell viability of RBL-2H3 decreased significantly under the degranulation state. After the intervention of Bla36, Bla80, and LC89, the cell viability increased by 76.54%, 51.66%, and 56.26% (P<0.0001) respectively compared with the model group, and the loratadine group was 14.65%, and the PBS was 10.08%, which had no significant effect on cell viability. Among the single postbiotic groups, Bla36 had the greatest effect on improving cell viability.

[0053] In the postbiotic combination group, after the intervention of Bla36+Bla80, the cell viability increased by 130.28%, which was 32.64% higher than that of Bla36+LC89. This shows that the effect of Bla36+Bla80 on the cell viability of RBL-2H3 cells in the degranulated state is not only better than that of all the groups intervened by single postbiotics, but also has the largest improvement in the combination group.

[0054] (2) Effects of postbiotic samples on cell FcεRI receptor expression

[0055] After 1 hour of excitation, 500 μL Trizol was added to the 12-well plate to extract total RNA, and the OD260 / OD280 values ​​were detected. After reverse transcription was completed according to the instructions of the reverse transcription kit, the cDNA sample was diluted 20 times and the fluorescence real-time quantitative reaction was performed according to the instructions of the q-PCR kit. The primers are shown in Table 3.

[0056] Table 3 Primer sequences

[0057]

[0058] FcεRI (high affinity IgE receptor) plays a central role in allergic reactions. It is highly expressed on the surface of mast cells and basophils and is a key receptor molecule that recognizes and transmits IgE signals and induces allergic reactions. Figure 2 As shown in the figure, compared with the blank group, the expression of FcεRImRNA in the model group increased by 2.44 times (P<0.0001), indicating that the expression of this receptor was significantly activated in degranulated cells. After the intervention of Bla36, Bla80, and LC89, the expression of FcεRImRNA decreased by 57.07% (P<0.0001), 45.45% (P<0.0001), and 37.68% (P<0.001) respectively compared with the model group, and the loratadine group was 28.02% (P<0.01). PBS had no significant effect on the cells, and the effect of inhibiting FcεRImRNA expression in the single postbiotic group was inferior to Bla36.

[0059] At the same time, in the postbiotic compound group, after the intervention of Bla36+Bla80, the expression of FcεRImRNA decreased by 70.01% (P<0.0001), which was 24.46% lower than that of Bla36+LC89, and better than all the groups of single postbiotics. This shows that Bla36+Bla80 has a synergistic effect, which can significantly inhibit the expression of FcεRImRNA in RBL-2H3 cells under degranulation, thereby improving the adverse effects of allergies caused by the activation of FcεRI subunits.

[0060] (3) Effects of animal Bifidobacterium lactis subsp. BLa36 postbiotic samples on cellular histamine secretion levels

[0061] After 1 hour of stimulation, the 12-well plate was collected from the cell culture supernatant, centrifuged at 2000rpm for 10min, and the supernatant was taken for the detection of histamine secretion level. The standard was diluted and added to the enzyme-labeled plate, and standard solutions of different concentrations were prepared, and then the sample to be tested was added and diluted. After the plate was sealed, it was incubated at 37°C for 30 minutes, and then the plate was washed 5 times with diluted washing solution. After that, the enzyme-labeled reagent (except the blank well) was added, and it was incubated and washed again. When developing color, color developer A was added first, and then color developer B was added, and the color was developed in the dark for 15 minutes. After terminating the reaction, the absorbance of each well at a wavelength of 450nm was measured. The entire measurement process must be completed within 15 minutes after terminating the reaction.

[0062] Histamine (HIS) is an important biogenic amine that plays a central role in allergic reactions. When the body encounters allergens, the immune system activates mast cells and basophils, which release histamine, triggering a series of physiological reactions such as capillary dilation, increased vascular permeability, and smooth muscle contraction. These reactions together lead to the appearance of allergic symptoms. Figure 3 As shown in the figure, compared with the blank group, the histamine content in the cell culture supernatant of the model group increased by 18.15% (P<0.05), indicating that the secretion level of histamine increased significantly under the degranulation state of RBL-2H3. After Bla36 intervention, the histamine secretion level decreased by 17.32% (P<0.01) compared with the model group, and loratadine, Bla80, LC89 and PBS had no significant effect on the cells.

[0063] At the same time, in the postbiotic compound group, after the intervention of Bla36+Bla80, the histamine secretion level decreased by 70.01% (P<0.01), while Bla36+LC89 had no significant effect. This shows that Bla36+Bla80 can significantly inhibit the histamine secretion level of RBL-2H3 cells in the degranulation state, enhance the effect of Bla80, and alleviate the adverse physiological reactions caused by the large amount of histamine secretion.

[0064] (4) Effects of postbiotic samples on the release rate of cellular β-hexosaminidase

[0065] After the cell supernatant was collected, 400 μL of 0.5% TritonX-100 was added to each well to completely dissolve the cells, and the supernatant was collected by centrifugation after 30 minutes.

[0066] Add 50 μL of supernatant to each well in a 96-well plate, then add 50 μL of color developer and incubate in an incubator for 1 hour; add 200 μL of terminator to each well and detect the OD value at 405 nm. Calculate the release rate (%) = (OD value of sample supernatant - OD value of normal group) / (OD value of total enzyme well - OD value of normal group) × 100%. Here [OD value of total enzyme well - OD value of normal group] is the OD value of dissolved cells.

[0067] β-Hexosaminidase (β-Hex) is a lysosomal enzyme that is often used as an indicator of mast cell and basophil activation and degranulation. Figure 4 As shown in the figure, compared with the blank group, the release rate of β-hexosaminidase in the model group increased by 1.21 times (P<0.0001), indicating that the secretion level of β-hexosaminidase increased significantly under the degranulation state of RBL-2H3. After the intervention of Bla36, the release rate of β-hexosaminidase decreased by 32.04% (P<0.001), and the release rates of β-hexosaminidase in the loratadine group were 23.81%, Bla80 was 23.92%, LC89 was 26.56%, and PBS was 29.77%. The inhibitory effects on the release of β-hexosaminidase in cells were weaker than Bla36, followed by Bla80 (P<0.01). This shows that Bla36 and Bla80 in the single epibiotic group have significant effects on inhibiting the secretion level of β-hexosaminidase.

[0068] In the postbiotic compound group, after the intervention of Bla36+Bla80, the release rate of β-hexosaminidase decreased by 36.22% (P<0.001), which was 12.96% greater than the reduction of Bla36+LC89, and better than the effect of the single postbiotic group. This shows that Bla36+Bla80 can synergistically enhance the effect and significantly inhibit the secretion level of β-hexosaminidase in RBL-2H3 cells under the degranulation state, thereby alleviating allergies caused by immune cell activation.

[0069] (5) Effects of postbiotic samples on the secretion level of cellular inflammatory factors

[0070] After 1 hour of stimulation, the 12-well plate was collected from the cell culture supernatant, centrifuged at 2000rpm for 10min, and the supernatant was taken to detect the secretion levels of inflammatory factors IL-4, IL-6 and TNF-α. The standard was diluted and added to the enzyme-labeled plate, and standard solutions of different concentrations were prepared to establish a standard curve, and then the sample to be tested was added and diluted. After the plate was sealed, it was incubated at 37°C for 30 minutes, and then the plate was washed 5 times with diluted washing solution. After that, the enzyme-labeled reagent (except the blank well) was added, and it was incubated and washed again. When developing color, color developer A was added first, and then color developer B was added, and the color was developed in the dark for 15 minutes. After terminating the reaction, the absorbance of each well at a wavelength of 450nm was measured, and the entire measurement process must be completed within 15 minutes after terminating the reaction.

[0071] IL-4 is a cytokine closely related to allergic reactions. In allergic reactions, the levels of these inflammatory factors are usually elevated, which is related to the inflammatory state of the disease and plays an important role in the occurrence and development of allergic reactions.

[0072] The results of the test on the secretion level of IL-4 in cells are as follows Figure 5 As shown in the figure, compared with the blank group, the IL-4 level of the model group cells was 198.09 ng / L, an increase of 21.64% (P<0.01), indicating that the IL-4 secretion level increased significantly under the degranulation state of RBL-2H3. After Bla36 intervention, the IL-4 level decreased by 27.96% (P<0.001); after LC89 intervention, the IL-4 level decreased by 21.39% (P<0.01); and loratadine, Bla80 and PBS had no significant intervention effect on the cells. This shows that Bla36 and LC89 have significant effects in single postbiotic groups. After compounding, after Bla36+Bla80 intervention, the IL-4 level decreased by 30.87% (P<0.001), which was 15.68% greater than the downregulation of Bla36+LC89, and better than the effects of single Bla36 and Bla80. This indicates that Bla36+Bla80 can synergistically enhance the efficacy and significantly inhibit the secretion level of IL-4 in RBL-2H3 cells under the degranulation state.

[0073] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A postbiotic preparation for regulating immune response, characterized in that: The postbiotic preparation for regulating immune response is composed of Bifidobacterium animalis subsp. Lactis BLa36 strain and Bifidobacterium animalis subsp. Lactis BLa80 strain; Wherein, the ratio of the number of live bacteria of Bifidobacterium animalis subsp. Lactis BLa36 strain to that of Bifidobacterium animalis subsp. Lactis BLa80 strain is 1-10:1-10.

2. The postbiotic preparation according to claim 1, characterized in that: The total number of viable bacteria in the postbiotic preparation is not less than 1×10 9 CFU / mL.

3. The postbiotic preparation according to claim 1 or 2, characterized in that: The strain Bifidobacterium animalis subsp. Lactis BLa36 is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 24029, a deposit date of December 2, 2021, and an address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the strain Bifidobacterium animalis subsp. Lactis BLa80 is deposited in the General Microbiology Center of the China Culture Collection Administration, with a deposit number of CGMCC No. 22547, a deposit date of May 17, 2021, and an address of No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

4. A method for preparing a postbiotic preparation for regulating immune response, characterized in that: The method comprises the following steps: inoculating Bifidobacterium animalis subsp. Lactis BLa36 and Bifidobacterium animalis subsp. Lactis BLa80 into MRS liquid culture medium for cultivation, centrifuging to obtain bacterial bodies, adjusting bacterial concentration with PBS, high pressure homogenizing, centrifuging, filtering and then mixing.

5. The preparation method according to claim 4, characterized in that: The culture temperature is 37° C. and the culture time is 12 to 18 hours.

6. The preparation method according to claim 4, characterized in that: The high pressure homogenization temperature is 4-10°C, the pressure is 250-310 MPa, and the number of times is 8-10 times.

7. An application of a postbiotic preparation for regulating immune response, characterized in that: The postbiotic preparation alleviates the decline in cell viability, IgE receptor activation, and excessive secretion of histamine, β-hexosaminidase, and inflammatory factors caused by immune disorders.

8. The use according to claim 7, characterized in that: The postbiotic preparation improves the viability of RBL-2H3 cells and inhibits the transcriptional expression of the IgE affinity receptor FcεRI.

9. The use according to claim 7, characterized in that: The postbiotic preparation weakens the release of histamine, a key factor in allergies, and downregulates the release rate of β-hexosaminidase, a marker of mast cell degranulation.

10. The use according to claim 7, characterized in that: The postbiotic preparation reduces the level of inflammatory factor IL-4.

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