A composition of seven probiotics for improving immunity and its application

Abstract

The present invention relates to a composition of seven probiotics for improving immunity and its use. The strains in the composition include Streptococcus thermophilus CT-02, Bifidobacterium animalis subsp. lactis C-2, Bifidobacterium longum subsp. infantis C-3, Lactobacillus delbrueckii subsp. bulgaricus CB-01, Lactobacillus acidophilus CL-01, Lactobacillus paracasei CL-02, and Lactobacillus rhamnosus CL-03. It was found that there is potential interaction between the seven strains. When used in combination, they can cooperate with each other and enhance synergy, showing excellent effects in improving immunity, alleviating inflammatory responses, and improving intestinal environmental health.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms, and particularly relates to a composition of seven probiotics for improving immunity and application thereof. Background Art

[0002] The immune system, the body's core defense against pathogens, relies on the dynamic synergy of immune organs, immune cells, and active substances. Immunity is a crucial defense mechanism for the body to resist pathogen invasion and maintain its health.

[0003] The intestine is the largest immune organ in the human body, and about 10 14 Individual microorganisms form a bidirectional regulatory network with the host immune system. The intestinal microbiota not only directly activates the innate immune response by metabolizing active substances such as short-chain fatty acids (SCFAs), but also regulates T lymphocyte subset differentiation and cytokine secretion via the gut-immune axis. However, external interference factors such as the intake of a high-fat diet can easily cause intestinal microbial disturbances, further weakening the immune barrier function and forming a vicious cycle of "microbial imbalance-immunosuppression."

[0004] Probiotics have become a research hotspot due to their inherent immunomodulatory properties. Specific probiotics, such as Lactobacillus rhamnosus GG, can activate dendritic cells through the TLR4 / MyD88 signaling pathway and promote the secretion of the Th1 cytokine IFN-γ. Bifidobacterium can also upregulate the expression of tight junction proteins in the intestinal epithelium, thereby enhancing the physical barrier function. Existing technologies often utilize a single strain or a simple combination of two or three strains, with their mechanisms of action limited to regulating a single immune indicator (such as enhancing IgA secretion). However, due to the highly heterogeneous human intestinal microbiome (including over 1,000 bacterial species competing for niches), it is difficult for a single strain to overcome colonization resistance and achieve stable proliferation. Furthermore, simple combination treatments can easily trigger metabolic competition between strains, resulting in insufficient coverage of immune regulatory nodes. Therefore, developing a complex probiotic product designed based on the metabolic interactions of multiple strains, which can achieve synergistic effects across multiple immune pathways, such as maintaining the intestinal barrier, activating immune cells, combating oxidative stress, or regulating inflammatory responses, has become a key approach to overcoming existing technological barriers. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the object of the present invention is to provide a composition of seven probiotics for improving immunity and its application.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a seven-probiotic composition for improving immunity, wherein the strains in the probiotic composition include Streptococcus thermophilus CT-02 strain with a preservation number of GDMCC No: 64474, Bifidobacterium animalissubsp. lactis C-2 strain with a preservation number of GDMCC No: 65455, Bifidobacterium longum subsp. infantis C-3 strain with a preservation number of GDMCC No: 64541, Lactobacillus delbrueckii subsp. bulgaricus CB-01 strain with a preservation number of GDMCC No: 64475, Lactobacillus acidophilus CL-01 strain with a preservation number of GDMCC No: 64731, and Lactobacillus acidophilus CL-01 strain with a preservation number of GDMCC No: A combination of Lacticaseibacillus paracasei CL-02 strain with a deposit number of GDMCC No: 64476 and Lacticaseibacillus rhamnosus CL-03 strain with a deposit number of GDMCC No: 65725.

[0008] The present invention develops a new probiotic compounding method and a new strategy for improving immunity, namely, seven bacterial strains, namely, Streptococcus thermophilus CT-02 strain, Bifidobacterium animalis subsp. lactis C-2 strain, Bifidobacterium longum subsp. infantis C-3 strain, Lactobacillus delbrueckii subsp. bulgaricus CB-01 strain, Lactobacillus acidophilus CL-01 strain, Lactobacillus paracasei CL-02 strain and Lactobacillus rhamnosus CL-03 strain, are compounded and used in combination. It is found that there are potential interactions among the seven strains, and they can cooperate with each other and synergize to enhance the effect. When the bacterial amount used is the same, the effect of the compound of the seven bacteria in improving immunity is significantly improved compared with the bacterial intervention method in which any bacterial species is missing.

[0009] Preferably, the ratio of the number of viable bacteria of the CT-02 strain, C-2 strain, C-3 strain, CB-01 strain, CL-01 strain, CL-02 strain and CL-03 strain is (1-10):(1-10):(0.1-5):(1-10):(5-15):(1-10):(0.1-5).

[0010] The above “1-10” may be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.;

[0011] The above-mentioned “0.1-5” can be, for example, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, etc.;

[0012] The above-mentioned "5-15" can be, for example, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, etc. Other specific point values ​​within this numerical range can be selected, and they will not be listed here one by one.

[0013] Based on the potential interaction between the seven strains, the present invention also found that when the seven strains are compounded and used in the above-mentioned specific ratio of viable bacteria count, the effect in improving the immunity level is more significant.

[0014] Preferably, the total viable bacterial concentration of the strains in the probiotic composition is not less than 1×10 8 CFU / mL or 1×10 8 CFU / g, for example 1×10 8 CFU / mL (CFU / g), 2×10 8 CFU / mL (CFU / g), 5×10 8 CFU / mL (CFU / g), 8×10 8 CFU / mL (CFU / g), 1×10 9 CFU / mL (CFU / g), 5×10 9 CFU / mL (CFU / g), 1×10 10 CFU / mL (CFU / g), etc. Other specific point values ​​within this numerical range can be selected and will not be described here one by one.

[0015] In a second aspect, the present invention provides a probiotic for improving immunity, wherein the probiotic comprises the probiotic composition described in the first aspect.

[0016] Preferably, the dosage form of the probiotic is selected from solution, lyophilized powder, capsule, tablet or granule.

[0017] Preferably, the probiotic further comprises a protective agent.

[0018] Preferably, the protective agent comprises any one or a combination of at least two of skim milk, sucrose, lactose, trehalose, dextran, gelatin, dextrin, gum arabic, sodium alginate, polyvinyl pyrrolidone, sorbitol, xylo-oligosaccharides, fructo-oligosaccharides or xylitol.

[0019] Preferably, the probiotic is in the form of a solution, which is prepared by the following method:

[0020] The strains are inoculated into culture medium respectively for activation and fermentation culture in sequence to obtain fermentation broth; the fermentation broth is centrifuged respectively and resuspended with a solvent to obtain bacterial suspensions of corresponding strains; the bacterial suspensions are mixed according to the ratio of viable bacteria count to obtain the probiotic agent.

[0021] Alternatively, the probiotic is in the form of a freeze-dried powder, which is prepared by the following method:

[0022] The strains are inoculated into culture medium respectively for activation and fermentation culture in sequence to obtain fermentation broth; the fermentation broth is centrifuged respectively, mixed with a protective agent and freeze-dried to obtain bacterial powder of the corresponding strain, and the bacterial powder is mixed according to the ratio of viable bacteria to obtain the probiotic agent.

[0023] Preferably, the culture medium comprises MRS medium or M17 medium.

[0024] Preferably, the MRS medium comprises, by concentration, the following: peptone 8-12 g / L, beef extract 8-12 g / L, glucose 15-25 g / L, sodium acetate 1-3 g / L, yeast powder 3-7 g / L, diammonium hydrogen citrate 1-3 g / L, K2PO4·3H2O 2-3 g / L, MgSO4·7H2O 0.05-0.2 g / L, MnSO4 0.01-0.1 g / L, Tween 80 0.5-2 mL / L, and cysteine ​​hydrochloride 0.1-1 g / L.

[0025] Preferably, the M17 medium comprises, by concentration, 3-7 g / L soy peptone, 3-7 g / L yeast extract, 3-7 g / L casein peptone, 0.1-1 g / L ascorbic acid, 1-10 g / L beef extract, and 15-25 g / L β-glycerophosphate disodium.

[0026] In a third aspect, the present invention provides a use of the probiotic composition as described in the first aspect or the probiotic agent as described in the second aspect in the preparation of food or health products.

[0027] In a fourth aspect, the present invention provides a use of the probiotic composition as described in the first aspect or the probiotic agent as described in the second aspect in preparing a preparation for preventing or alleviating liver damage caused by inflammatory factors, spleen damage caused by inflammatory factors, or inflammatory bowel disease.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The present invention develops a new probiotic compounding method and a new strategy for improving immunity, namely, seven bacterial strains, namely, Streptococcus thermophilus CT-02 strain, Bifidobacterium animalis subsp. lactis C-2 strain, Bifidobacterium longum subsp. infantis C-3 strain, Lactobacillus delbrueckii subsp. bulgaricus CB-01 strain, Lactobacillus acidophilus CL-01 strain, Lactobacillus paracasei CL-02 strain and Lactobacillus rhamnosus CL-03 strain, are compounded and used in combination. It is found that there are potential interactions among the seven strains, and they can cooperate with each other and synergize to enhance the effect. When the bacterial amount used is the same, the effect of the compound of the seven bacteria in improving immunity is significantly improved compared with the bacterial intervention method in which any bacterial species is missing.

[0030] The CT-02 strain involved in the present invention is classified as Streptoccus thermophilus, and the depository is Guangdong Provincial Microbiological Culture Collection Center, with a deposit number of GDMCC No: 64474, a deposit date of March 29, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0031] The C-2 strain involved in the present invention is classified as Bifidobacterium animalis subsp. lactis, and the depository is Guangdong Provincial Microbial Culture Collection Center, with a deposit number of GDMCC No: 65455, a deposit date of November 8, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0032] The C-3 strain involved in the present invention is classified as Bifidobacterium longum subsp. infantis, and the depository is Guangdong Provincial Microbial Culture Collection Center, with a deposit number of GDMCC No: 64541, a deposit date of April 22, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0033] The CB-01 strain involved in the present invention is classified as Lactobacillus delbrueckii subsp.bulgaricus, and the depository is Guangdong Provincial Microbiological Culture Collection Center, with a deposit number of GDMCC No: 64475, a deposit date of March 29, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0034] The CL-01 strain involved in the present invention is classified as Lactobacillus acidophilus, and the depository is Guangdong Provincial Microbiological Culture Collection Center, with a deposit number of GDMCC No: 64731, a deposit date of June 7, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0035] The CL-02 strain involved in the present invention is classified as Lacticaseibacillus paracasei, and the depository is Guangdong Provincial Microbiological Culture Collection Center, with a deposit number of GDMCC No: 64476, a deposit date of March 29, 2024, and a deposit address of 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou;

[0036] The CL-03 strain involved in the present invention is classified as Lacticaseibacillus rhamnosus, the depository is Guangdong Provincial Microbial Culture Collection Center, the deposit number is GDMCC No: 65725, the deposit date is February 21, 2025, and the deposit address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a statistical graph showing the changes in body weight of each group of mice before and after modeling;

[0038] Figure 2 This is a statistical result graph of the levels of TNF-α, IL-6, IFN-γ and IL-10 factors in the serum of each group of mice;

[0039] Figure 3 This is a statistical graph of IgA and IgG levels in the serum of mice in each group;

[0040] Figure 4 Figure 2 is the histopathological observation and analysis results of liver sections of mice in groups S1, S10, and S11;

[0041] Figure 5 This is a statistical graph of the alanine aminotransferase levels in the serum of mice in each group;

[0042] Figure 6 Figure 2 is the histopathological observation and analysis results of spleen sections of mice in groups S1, S10, and S11;

[0043] Figure 7 This is a statistical result chart of the ratio of reduced glutathione to oxidized glutathione levels in the spleen tissue of each group of mice;

[0044] Figure 8Figure 2 is the histopathological observation and analysis results of intestinal sections of mice in groups S1, S10, and S11;

[0045] Figure 9 This is a statistical result graph of the levels of TNF-α, IL-6, INF-γ and IL-10 factors in the intestinal tissues of each group of mice;

[0046] Figure 10 This is a statistical graph of IgA levels in fecal samples from each group of mice. DETAILED DESCRIPTION

[0047] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0048] The following bacterial species information is:

[0049] ① The CT-02 strain involved below is named Streptoccus thermophilus and its deposit number is GDMCC No: 64474;

[0050] ② The C-2 strain involved below is named Bifidobacterium animalis subsp. lactis and its deposit number is GDMCC No: 65455;

[0051] ③ The C-3 strain involved below is named Bifidobacterium longum subsp. infantis and its deposit number is GDMCC No: 64541;

[0052] ④ The CB-01 strain involved below is designated as Lactobacillus delbrueckii subsp.bulgaricus and its deposit number is GDMCC No: 64475;

[0053] ⑤ The CL-01 strain involved below is named Lactobacillus acidophilus and its deposit number is GDMCC No: 64731;

[0054] ⑥ The CL-02 strain involved below is designated as Lacticaseibacillus paracasei and its deposit number is GDMCC No: 64476;

[0055] ⑦ The CL-03 strain referred to below is designated as Lacticaseibacillus rhamnosus and its deposit number is GDMCC No: 65725.

[0056] The culture medium and its formula involved below are:

[0057] The mice involved in the following are C57BL / 6J male mice (6 weeks old) obtained from Spefox (Beijing) Biotechnology Co., Ltd.

[0058] The following method for preparing bacterial suspension and bacterial powder is as follows: after activating the strain, inoculate it into culture medium for cultivation to obtain culture solution; centrifuge the culture solution, resuspend the bacteria to obtain bacterial suspension, or further add a protective agent and freeze-dry to obtain a freeze-dried bacterial powder product.

[0059] GraphPad 8.0 statistical software was used to prepare histograms, and the values ​​were expressed as mean ± SEM.

[0060] Example 1

[0061] This example explores the ability of compound probiotics to improve various indicators of inflammatory mice

[0062] (1) Experimental animals: 6-week-old C57BL / 6J male mice, housed in a laboratory under specific pathogen-free conditions with a 12-h daylight cycle, a temperature of 22±2°C, and a relative humidity of 55%±10%.

[0063] (2) Animal grouping and modeling: The mice were randomly grouped after one week of adaptive feeding as shown in Table 1:

[0064] Table 1

[0065]

[0066] Among them, each group in the above table had 6 mice, and the total viable bacterial count in each group of S1-S9 was 1×10 9 CFU / mL.

[0067] (3) Intervention method: During the experiment, mice in each group had free access to food and water.

[0068] From day 8 to day 35 of the experiment, groups S1-S9 received daily gavage of the corresponding compound probiotic suspension, 250 μL each time, twice daily. Groups S10 and S11 received an equal volume of sterile saline twice daily. On day 36, all groups except group S11 received an intraperitoneal injection of 5 mg / kg bw lipopolysaccharide (LPS, Escherichia coli O55:B5). Twenty-four hours after model establishment, mice were anesthetized and sacrificed, and samples were collected.

[0069] (4) Index test

[0070] ① Mouse weight analysis

[0071] The weight of mice in each group was counted before and after modeling, and the difference in weight change between the 36th day (before modeling) and the 37th day (after modeling) of the experiment was calculated. Figure 1 The feces shape and health status of the mice were observed at the same time, and the results are shown in Table 2.

[0072] Table 2

[0073]

[0074] As shown in the statistical results in the figure, after the experiment, the mice in the S10 (model group) group showed a significant weight loss and developed soft and loose stools, messy fur, curled up, less active, listless, and unresponsive, proving that the model was successful. After probiotic intervention, the weight loss of mice in each probiotic intervention group was alleviated to varying degrees. Among them, a comparison between the S1 group and the S3-S9 groups showed that when the composite probiotics lacked any one of the seven strains CT-02, C-2, C-3, CB-01, CL-01, CL-02, and CL-03, the effect was worse than that of the S1 group. This shows that the present invention uses the above seven specific probiotics for compound use, which can synergistically enhance the effect of improving the weight loss level of inflammatory mice.

[0075] ② Analysis of mouse serum cytokine levels

[0076] After the experiment, the serum of mice in each group was collected and centrifuged at 2000×g and 4°C for 15 min. The levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), interferon-γ (IFN-γ), immunoglobulin A (IgA), and immunoglobulin G (IgG) in the serum were determined according to the instructions of the ELISA kit. The results were as follows: Figure 2 and Figure 3 shown.

[0077] Lipopolysaccharides (LPS) derived from Gram-negative bacteria can directly activate mammalian innate immune cells to produce large amounts of inflammatory mediators, which can directly or indirectly damage host cells or tissues. As shown in the figure, compared with the S11 (blank group), the serum levels of the pro-inflammatory factors IL-6, TNF-α, and IFN-γ in the S10 (model group) mice were significantly elevated, while the level of the anti-inflammatory factor IL-10 was significantly decreased. At the same time, the release of the pro-inflammatory factors IL-6 and TNF-α further stimulated B cells to produce more IgA and IgG. This indicates that LPS injection can activate immune cells, leading to the production and release of a large number of inflammatory factors in mice, while suppressing the expression of anti-inflammatory factors.

[0078] After probiotic intervention, the levels of proinflammatory factors in mice in each probiotic intervention group were reduced to varying degrees, while the levels of anti-inflammatory factors were significantly increased. Among them, a comparison between the S1 group and the S3-S9 groups showed that when the composite probiotics lacked any one of the seven strains CT-02, C-2, C-3, CB-01, CL-01, CL-02 and CL-03, the effects were all worse than those in the S1 group. It can be seen that the present invention uses the above-mentioned seven specific probiotics for compound use, which can synergistically enhance the effect, prevent LPS from stimulating the mouse immune system, reduce the release of inflammatory factors, and inhibit excessive inflammation, thereby further reducing the excessive activation of B cells and the production of immunoglobulins IgA and IgG.

[0079] ③ Analysis of liver damage level

[0080] a. After the experiment, liver tissues of mice in groups S1, S10, and S11 were collected for H&E staining and sectioning. The results of the section analysis were as follows: Figure 4 shown.

[0081] As can be seen from the figure, in S11 (blank group), the mouse hepatocytes are arranged in a lamellar structure with the central vein as the center, and several bile ducts can be seen between the hepatic lobules; the hepatocyte cytoplasm is rich, the cell nucleus is located in the center of the cell, and no obvious histopathological changes are observed; in the S10 (model group) mouse liver, mild multifocal hepatocyte swelling and degeneration are observed, manifested as enlarged hepatocytes, translucent cytoplasm, and narrowed sinusoidal spaces; in the S1 group, no obvious histopathological changes are observed in the mouse liver after probiotic intervention treatment. It can be seen that the probiotic composition provided by the present invention can effectively alleviate the symptoms related to liver damage caused by lipopolysaccharide-induced inflammatory response.

[0082] b. Take the serum of each group of mice and use ELISA kit to measure the level of alanine aminotransferase (ALT). The statistical results are as follows: Figure 5 shown.

[0083] LPS, whether intestinal or exogenously administered, can translocate to the liver and further impair liver function. Among biomarkers of liver injury, alanine aminotransferase (ALT) is a key indicator of hepatocellular damage. When hepatocellular damage occurs, ALT is released from the cells into the blood, leading to elevated ALT levels. As shown in the figure, intraperitoneal LPS injection induced hepatocellular damage in mice. ALT levels in the serum of S10 mice (model group) were significantly elevated. Combined with biopsy results, extensive fat accumulation and inflammatory cell infiltration in the livers of these mice indicate that the inflammatory model was successfully established. Following probiotic treatment, the severity of liver damage in all probiotic treatment groups was alleviated, demonstrating that the combined use of seven strains (CT-02, C-2, C-3, CB-01, CL-01, CL-02, and CL-03) synergistically mitigates LPS-induced liver injury.

[0084] ④ Splenic damage level

[0085] a. After the experiment, some spleen tissues of mice in groups S1, S10, and S11 were collected for H&E staining and sectioning. The results of the section analysis were as follows: Figure 6 shown.

[0086] As can be seen from the figure, dark blue lymphoid tissue can be seen in the spleen tissue of S11 (blank group) mice forming white pulp, distributed between the dark red red pulp, and no obvious histopathological changes were observed; while in the spleen of S10 (model group) mice, mild white pulp germinal center lymphocyte necrosis and mild white pulp atrophy symptoms were observed, specifically manifested as a decrease in lymphocytes in the periarterial lymphoid sheaths; and in the S1 group treated with probiotics, only mild white pulp germinal center lymphocyte necrosis was observed in the spleen tissue of mice, indicating that the seven probiotic compositions provided by the present invention can effectively alleviate the symptoms related to spleen damage induced by increased inflammation levels.

[0087] b. Part of the spleen tissue of each group of mice was homogenized and the reduced glutathione (GSH) and oxidized glutathione (GSSG) contents were determined according to the reagents and instructions, and the GSH / GSSG ratio was calculated. The results are shown in the figure below. Figure 7 shown.

[0088] LPS stimulates macrophages to secrete pro-inflammatory cytokines such as TNF-α, IL-6, and INF-γ. These cytokines, by impairing mitochondrial integrity and function, lead to increased production and production of reactive oxygen species (ROS), exacerbating GSH depletion and resulting in a decreased GSH / GSSG ratio. As shown in the figure, the GSH / GSSG ratio in the S10 (model) sample was significantly lower than that in the S11 (blank) sample. Staining of sections revealed the recruitment of numerous immune cells (such as monocytes, lymphocytes, and neutrophils) to the spleen, resulting in spleen enlargement due to immune cell infiltration and proliferation, and pathological changes such as inflammatory cell infiltration, congestion, hemorrhage, and necrosis. Probiotic treatment alleviated oxidative stress in the spleen of mice in all probiotic treatment groups, demonstrating that the combined use of the seven strains CT-02, C-2, C-3, CB-01, CL-01, CL-02, and CL-03 synergistically improves LPS-induced oxidative stress in the spleen.

[0089] ⑤ Analysis of intestinal barrier function

[0090] a. After the experiment, some intestinal tissues of mice in groups S1, S10, and S11 were collected for PAS staining and sectioning. The results of the section analysis were as follows: Figure 8 shown.

[0091] As can be seen from the figure, wrinkled structures can be seen in the colon mucosa of S11 (blank group) mice, which contain relatively rich intestinal glands. PAS staining shows that goblet cells are blue-purple, and no obvious histopathological changes are observed. Compared with S11 (blank group), the colon mucosa of S10 (model group) mice showed mild to moderate atrophy, which was specifically manifested by shortening of the mucosa and intestinal glands, a decrease in the number of goblet cells, and expansion of the intestinal cavity. In the S1 group treated with probiotics, the colon mucosa of mice only showed mild to mild atrophy symptoms. It can be seen that the composition composed of seven probiotics provided by the present invention can effectively alleviate related intestinal damage symptoms.

[0092] b. Part of the intestinal tissue of each group of mice was homogenized and the levels of TNF-α, IL-6, INF-γ and IL-10 were measured according to the reagents and instructions. The results are as follows: Figure 9 shown.

[0093] As shown in the figure, after intraperitoneal injection of lipopolysaccharide into mice, the levels of the pro-inflammatory factors TNF-α, IL-6, and INF-γ in the colon tissue of the S10 (model group) mice were significantly elevated compared to the levels of the relevant factors in the S11 (blank group) samples, while the level of the anti-inflammatory factor IL-10 was significantly decreased. After probiotic intervention, the intestinal barrier damage of mice in all probiotic intervention groups was alleviated, indicating that the seven strains CT-02, C-2, C-3, CB-01, CL-01, CL-02, and CL-03 can synergize and effectively improve the barrier damage caused by LPS.

[0094] ⑥ Analysis of related immunoglobulin levels in intestinal contents

[0095] After the experiment, the feces of the mice were collected and the levels of secretory immunoglobulin-A (IgA) in the fecal samples of each group of mice were determined according to the instructions of the ELISA kit. Figure 10 shown.

[0096] IgA is the primary antibody produced by the intestinal mucosa. Observing the levels of related factors in fecal samples can, to a certain extent, reflect the host's intestinal health and inflammation levels. As shown in the figure, after intraperitoneal injection of lipopolysaccharide (LPS), IgA antibody levels in the intestines of S10 (model group) mice were significantly elevated compared to the levels of related factors in S11 (blank group) samples. Following probiotic intervention, intestinal inflammation symptoms were alleviated in all probiotic intervention groups, demonstrating that the seven strains, CT-02, C-2, C-3, CB-01, CL-01, CL-02, and CL-03, synergistically enhance efficacy, effectively improving LPS-induced intestinal inflammation symptoms and demonstrating excellent results.

[0097] The applicant declares that the present invention is illustrated by the above-described embodiments, but the present invention is not limited to the above-described embodiments. This does not mean that the present invention must rely on the above-described embodiments in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for raw materials in the present invention, additions of auxiliary ingredients, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0098] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the scope of protection of the present invention.

[0099] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A composition of seven probiotics for improving immunity, characterized in that: The strain in the probiotic composition is Streptococcus thermophilus with a viable cell count ratio of (1-10):(1-10):(0.1-5):(1-10):(5-15):(1-10):(0.1-5) and a deposit number of GDMCC No: 64474. Streptoccus thermophilus CT-02 strain, Bifidobacterium animalis subsp. lactis with a deposit number of GDMCC No: 65455 Bifidobacterium animalis subsp. lactis C-2 strain, Bifidobacterium longum subsp. infantis with a deposit number of GDMCC No: 64541 Bifidobacterium longum subsp. infantis C-3 strain, Lactobacillus delbrueckii subsp. bulgaricus with a deposit number of GDMCC No: 64475 Lactobacillus delbrueckii subsp. bulgaricus CB-01 strain, Lactobacillus acidophilus with a deposit number of GDMCC No: 64731 Lactobacillus acidophilus CL-01 strain, Lactobacillus paracasei with a deposit number of GDMCC No: 64476 Lacticaseibacillus paracasei CL-02 strain and Lactobacillus rhamnosus with a deposit number of GDMCC No: 65725 Lacticaseibacillus rhamnosus Combination of CL-03 strains.

2. The probiotic composition according to claim 1, wherein The total viable bacterial concentration of the strains in the probiotic composition is not less than 1×10 8 CFU / mL or 1×10 8 CFU / g.

3. A probiotic for improving immunity, characterized in that: The active ingredient in the probiotic is the probiotic composition according to claim 1.

4. The probiotic according to claim 3, wherein The dosage form of the probiotic is selected from solution, lyophilized powder, capsule, tablet or granule.

5. The probiotic according to claim 3, wherein The probiotic also includes a protective agent.

6. The probiotic according to claim 5, wherein The protective agent includes any one of skim milk, sucrose, lactose, trehalose, dextran, gelatin, dextrin, gum arabic, sodium alginate, polyvinyl pyrrolidone, sorbitol, oligoxylose, oligofructose or xylitol, or a combination of at least two thereof.

7. The probiotic according to claim 4, wherein The dosage form of the probiotic is a solution, which is prepared by the following method: The strains are inoculated into culture medium respectively for activation and fermentation in sequence to obtain fermentation broth; the fermentation broth is centrifuged and resuspended with a solvent to obtain bacterial suspensions of the corresponding strains; the bacterial suspensions are mixed according to the ratio of viable bacteria count to obtain the probiotic agent; Alternatively, the probiotic is in the form of a freeze-dried powder, which is prepared by the following method: The strains are inoculated into culture medium respectively for activation and fermentation culture in sequence to obtain fermentation broth; the fermentation broth is centrifuged respectively, mixed with a protective agent and freeze-dried to obtain bacterial powder of the corresponding strain, and the bacterial powder is mixed according to the ratio of viable bacteria to obtain the probiotic agent.

8. Use of the probiotic composition according to claim 1 or 2 or the probiotic agent according to any one of claims 3 to 7 in the preparation of food or health products.

9. Use of the probiotic composition according to claim 1 or 2 or the probiotic agent according to any one of claims 3 to 7 in the preparation of a preparation for preventing or alleviating liver damage caused by inflammatory factors, spleen damage caused by inflammatory factors, or inflammatory bowel disease.

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