A strain of Bifidobacterium longum subspecies longum for lowering blood pressure and blood lipids, and its postbiotics and applications

Abstract

The invention discloses a strain of Bifidobacterium longum subspecies longum for lowering blood pressure and blood lipids, and its postbiotics and applications, and relates to the technical field of microbial fermentation. The invention screens and obtains a strain of Bifidobacterium longum subspecies longum ( Bifidobacterium longum subsp. long )WZA‑BL01, which has a deposit number of: CCTCC NO: M 20241531. The long subspecies of Bifidobacterium longum is obtained by fermenting and culturing the long subspecies of Bifidobacterium longum, and the long subspecies of Bifidobacterium longum postbiotics are combined with natto extract and mulberry leaf extract to prepare a blood pressure and blood lipid lowering product. The product can significantly reduce the tail vein pressure and the content of total cholesterol, triglycerides, and low-density lipoprotein in rats, and increase the content of high-density lipoprotein. It can be seen that the long subspecies of Bifidobacterium longum and its postbiotics obtained by the present invention can have the dual effects of lowering blood pressure and lowering blood lipids.

Description

Technical Field

[0001] The invention relates to the technical field of microbial fermentation, and in particular to a strain of Bifidobacterium longum subspecies longum capable of lowering blood pressure and blood lipids, and postbiotics and applications thereof. Background Art

[0002] Modern physiology believes that blood pressure is the lateral pressure on the blood vessel wall per unit area when blood flows in the blood vessels. It is the driving force for blood to flow in the blood vessels. Hypertension refers to blood pressure that continues to exceed normal values, causing the blood vessel wall to bear higher pressure than normal for a long time, resulting in brittle damage to the blood vessels, thereby damaging the functions of organs such as the heart, brain, and kidneys. Blood lipids are essential substances for the basic metabolism of living cells, including neutral fats such as triglycerides and lipids such as cholesterol. Hyperlipidemia (dyslipidemia) refers to the long-term excess of cholesterol or triglycerides in plasma, which causes blood lipids to deposit on the blood vessel wall, block blood vessels, and induce diseases of organs such as the brain, kidneys, and eyes. Both hyperlipidemia and hypertension are chronic diseases, and the two usually trigger each other, that is, hypertension can cause hyperlipidemia, and hyperlipidemia can also cause hypertension. Therefore, in the treatment of high blood pressure and dyslipidemia, it is necessary to treat it with a comprehensive prevention and treatment concept, and it is not enough to simply lower blood pressure or blood lipids.

[0003] Postbiotics are a general term for the metabolites of probiotics after probiotics are processed. Because they do not contain live bacteria, they have high biosafety. At the same time, their small molecules can quickly enter the body through the intestinal mucosa and have direct and rapid functionality. Many evidences show that postbiotics may be beneficial to the management of metabolic diseases through potential effects, among which hypertension and dyslipidemia are typical metabolic diseases.

[0004] Bifidobacterium longum is widely found in the intestines of humans and animals. It is included in the "List of Bacteria that can be used in Food" and "List of Bacteria that can be used in Infant Food" in my country. It includes Bifidobacterium longum subspecies longum ( Bifidobacterium longum subsp. . long ), Bifidobacterium longum subsp. infantis ( Bifidobacterium longum subsp. . child ) etc. In the prior art, CN181146998A discloses a strain of Bifidobacterium longum subspecies long KS1 and its application in the preparation of anti-aging and sleep-aiding food and medicine, wherein the Bifidobacterium longum subspecies long KS1 can be used as a renin inhibitor to prevent and treat hypertension, but it cannot play a lipid-lowering effect, and CN116814501B discloses a Bifidobacterium longum subspecies long for alleviating obesity and its application, which can only reduce blood lipid levels but cannot reduce blood pressure.

[0005] Therefore, a strain of Bifidobacterium longum subsp. longum ( Bifidobacterium longum subsp. . long), and it is necessary to use it to prepare corresponding postbiotics to achieve the dual effects of lowering blood pressure and lowering blood lipids. Summary of the invention

[0006] In view of the above-mentioned prior art, the purpose of the present invention is to provide a strain of Bifidobacterium longum subspecies longum for lowering blood pressure and blood lipids, and its postbiotics and applications.

[0007] To achieve the above object, the present invention adopts the following technical solution:

[0008] In a first aspect of the present invention, a strain of Bifidobacterium longum subspecies longum ( Bifidobacterium longum subsp. . long )WZA-BL01, the strain was deposited in the China Center for Type Culture Collection (CCTCC, located at Wuhan University, No. 299, Bayi Road, Wuchang District, Wuhan City, Hubei Province) on July 10, 2024, and its deposit number is: CCTCC NO:M 20241531.

[0009] A second aspect of the present invention provides a Bifidobacterium longum subsp. longum postbiotic, which is prepared by the following method:

[0010] (1) inoculating Bifidobacterium longum subspecies longum into a fermentation medium and fermenting to obtain a fermentation liquid;

[0011] (2) After the fermentation liquid is centrifuged, the supernatant is collected and dried to obtain Bifidobacterium longum subsp. longum postbiotics.

[0012] Preferably, in step (1), the components of the fermentation medium are: peptone 10-20 g / L, glucose 15-25 g / L, yeast extract 1.5-2.5 g / L, soluble starch 0.3-0.6 g / L, sodium chloride 3-6 g / L, L-cysteine ​​0.3-0.6 g / L, tomato extract 3-6 g / L, liver extract 1.5-2.5 g / L, Tween-80 0.5-1.5 mL / L, and Sophora japonica extract 30-50 mg / L, pH: 7.0±0.1 (25°C).

[0013] Further preferably, the preparation method of the Sophora japonica extract is: after mixing Sophora japonica and water in a solid-liquid ratio of (80-100) g: 500 mL, decocting for 2-3 times, combining the decoctions, and drying to obtain the Sophora japonica extract.

[0014] More preferably, the decoction time is 2-3h.

[0015] Preferably, in step (1), the fermentation temperature is 35-40°C and the fermentation time is 48-72h.

[0016] Preferably, in step (1), the inoculation amount of Bifidobacterium longum subspecies longum is 10-20% of the volume of the fermentation medium.

[0017] The third aspect of the present invention provides the use of Bifidobacterium longum subsp. longum or Bifidobacterium longum subsp. longum postbiotics in the preparation of blood pressure and blood lipid lowering products.

[0018] Preferably, the blood pressure and blood lipid lowering product is prepared from Bifidobacterium longum subsp. longum postbiotics, natto extract and mulberry leaf extract in a ratio of 1:1:1.

[0019] Preferably, the preparation method of the mulberry leaf extract is: after mixing mulberry leaves and water in a mass ratio of 1:20, heating and refluxing for extraction for 3 times, combining the extraction liquids, filtering and drying, thereby obtaining the mulberry leaf extract.

[0020] Preferably, the preparation method of the natto extract is: mixing Bacillus subtilis seed liquid and Kluyveromyces marxianus seed liquid in a ratio of 1:1 to obtain a mixed seed liquid, inoculating the mixed seed liquid into a soybean culture medium, fermenting at 37°C for 48 hours to obtain a fermentation liquid, centrifuging the fermentation liquid, taking the supernatant and drying it to obtain the natto extract.

[0021] Further preferably, the inoculation amount of the mixed seed solution is 10% of the volume of the soybean culture medium.

[0022] More preferably, the strain number of Bacillus subtilis is ACCC 19373, and the strain number of Kluyveromyces marxianus is ACCC 21190.

[0023] Further preferably, the components of the soybean culture medium are: 80 g / L soybean powder, 20 g / L peptone, and 10 g / L sucrose.

[0024] Beneficial effects of the present invention:

[0025] The present invention obtains Bifidobacterium longum subspecies longum ( Bifidobacterium longum subsp. . long )WZA-BL01, the long subspecies of Bifidobacterium longum is fermented and cultured to obtain the long subspecies of Bifidobacterium longum postbiotics, and the long subspecies of Bifidobacterium longum is compounded with natto extract and mulberry leaf extract to obtain a composition, which is a product for lowering blood pressure and blood lipids. The product can significantly reduce the tail vein pressure (systolic blood pressure) of SHR rats, and can also significantly reduce the content of total cholesterol, triglycerides, etc. in rat serum, and increase the content of high-density lipoprotein. It can be seen that the product prepared by the present invention can have the effects of lowering blood pressure and lowering blood lipids at the same time. It can be seen from the experimental data that the long subspecies of Bifidobacterium longum postbiotics, natto extract and mulberry leaf extract have a synergistic effect in lowering blood pressure and blood lipids. In addition, the present invention can improve the blood pressure and blood lipid lowering effects of the long subspecies of Bifidobacterium longum postbiotics by adding Sophora japonica extract to the fermentation medium, thereby improving the efficacy of the blood pressure and blood lipid lowering products. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0027] In order to enable those skilled in the art to more clearly understand the technical solution of the present application, the technical solution of the present application will be described in detail below in conjunction with specific embodiments.

[0028] The test materials used in the examples of the present invention are all conventional test materials in the art and can be purchased through commercial channels.

[0029] Among them, the SPF-grade male SHR rats were purchased from Beijing Weitonglihua Experimental Animal Technology Co., Ltd., the SPF-grade male SD rats and basic feed were purchased from Jinan Pengyue Experimental Animal Breeding Co., Ltd., and the Bacillus subtilis and Kluyveromyces marxianus were purchased from China Agricultural Microbiological Culture Collection Center, with strain numbers ACCC 19373 and ACCC 21190, respectively.

[0030] Example 1: Isolation and identification of strains

[0031] 1. Isolation and initial screening of strains

[0032] 10g of fecal sample from healthy adults was collected and diluted 10-fold with PBS diluent. -4 , 10 -5 , 10 -6 and 10 -7 At each dilution, 100 μL was spread on a modified MRS solid medium, cultured anaerobically at 37 °C for 48 h, and the colony morphology was recorded.

[0033] Single colonies with round, convex, smooth, neatly edged, and opaque milky white morphology were selected for streak purification. The above colonies were then inoculated in MRS liquid culture medium for anaerobic culture. The obtained colonies were Gram-stained, and Gram-positive and catalase-negative strains were selected. They were streaked and purified on MRS culture medium for more than 3 times. Colonies with larger colonies and stronger reproductive ability were selected, numbered, and inoculated on MRS solid plates for streak purification culture.

[0034] 2. Screening of strains: acid resistance and bile resistance

[0035] The activated strain was inoculated into MRS medium for anaerobic culture at 37°C for 24 hours, and then centrifuged. The precipitate after centrifugation was resuspended in PBS to obtain a bacterial suspension.

[0036] The bacterial suspension was inoculated into MRS medium with pH values ​​of 2.0, 3.0, 4.0, 5.0 and 6.0 and MRS medium with bile salt concentration (w / v) of 0.1%, 0.2%, 0.3%, 0.4% and 0.5%, respectively. MRS medium with pH value of 7.0 and MRS medium without bile salt were used as blank control groups, and the number of viable bacteria was counted and the survival rate was calculated. Strains with higher survival rates were selected for subsequent identification.

[0037] 3. Identification of strains

[0038] The WZA-BL01 strain was sent to the Henan Industrial Microbial Strain Engineering Technology Research Center for 16SrDNA gene sequence identification. The 16SrDNA gene sequence is shown in SEQ ID NO.1.

[0039] The identification results showed that the strain belonged to Bifidobacterium longum subspecies longum ( Bifidobacterium long subsp. long ), and the strain was biologically deposited. The deposit information is as follows:

[0040] Bacterial species name: Bifidobacterium longum subspecies longum WZA-BL01

[0041] Latin name: Bifidobacterium longum subsp. long

[0042] Collection institution: China Center for Type Culture Collection

[0043] Abbreviation of depository institution: CCTCC

[0044] Address: Wuhan University, No. 299 Bayi Road, Wuchang District, Wuhan City, Hubei Province

[0045] Deposit date: July 10, 2024

[0046] Deposit number: CCTCC No: M 20241531.

[0047] Example 2: Preparation of Bifidobacterium longum subsp. longum postbiotics

[0048] (1) After activating Bifidobacterium longum subspecies longum, inoculate it into the fermentation medium at a volume ratio of 15%, and ferment it at 37°C for 48 hours to obtain a fermentation liquid;

[0049] The fermentation medium comprises the following components: 15 g / L peptone, 20 g / L glucose, 2.0 g / L yeast extract, 0.5 g / L soluble starch, 5.0 g / L sodium chloride, 0.5 g / L L-cysteine, 5.0 g / L tomato extract, 2.0 g / L liver extract, 1.0 ml / L Tween-80, 40 mg / L Sophora japonica extract, pH: 7.0 (25°C);

[0050] The sophora japonica extract is prepared by the following method: after mixing sophora japonica and water in a solid-liquid ratio of 90 g:500 mL, decocting for 3 times, each decocting time is 3 hours, combining the decoctions, and drying to obtain the sophora japonica extract;

[0051] (2) After the fermentation liquid is centrifuged, the supernatant is taken out and freeze-dried to obtain Bifidobacterium longum subsp. longum postbiotics;

[0052] Collect the bacterial precipitate after centrifugation and adjust the number of viable bacteria in the bacterial precipitate to 2×10 9 cfu / g and stored in a refrigerator at 4°C for later use.

[0053] Example 3: Preparation of Bifidobacterium longum subsp. longum postbiotics

[0054] (1) Activating the Bifidobacterium longum subspecies longum preserved in Example 1, inoculating 10% (volume ratio) into a fermentation medium, and fermenting at 35° C. for 72 h to obtain a fermentation broth;

[0055] The fermentation medium comprises the following components: peptone 10 g / L, glucose 15 g / L, yeast extract 1.5 g / L, soluble starch 0.3 g / L, sodium chloride 3.0 g / L, L-cysteine ​​0.3 g / L, tomato extract 3.0 g / L, liver extract 1.5 g / L, Tween-80 0.5 ml / L, Sophora japonica extract 30 mg / L, pH: 7.0 (25°C);

[0056] The sophora japonica extract is prepared by the following method: after mixing sophora japonica and water in a solid-liquid ratio of 80 g:500 mL, decocting twice, each decocting time is 2.5 hours, combining the decoctions, and drying to obtain the sophora japonica extract;

[0057] (2) After the fermentation liquid is centrifuged, the supernatant is collected and freeze-dried to obtain Bifidobacterium longum subsp. longum postbiotics.

[0058] Example 3: Preparation of Bifidobacterium longum subsp. longum postbiotics

[0059] (1) Activating the Bifidobacterium longum subspecies longum preserved in Example 1, inoculating 20% ​​(volume ratio) into a fermentation medium, and fermenting at 40° C. for 48 hours to obtain a fermentation broth;

[0060] The fermentation medium comprises the following components: 20 g / L peptone, 25 g / L glucose, 2.5 g / L yeast extract, 0.6 g / L soluble starch, 6.0 g / L sodium chloride, 0.6 g / L L-cysteine, 6.0 g / L tomato extract, 2.5 g / L liver extract, 1.5 ml / L Tween-80, 50 mg / L Sophora japonica extract, pH: 7.0 (25°C);

[0061] The sophora japonica extract is prepared by the following method: after mixing sophora japonica and water in a solid-liquid ratio of 100 g: 500 mL, decocting twice, each decocting time is 2.5 hours, combining the decoctions, and drying to obtain the sophora japonica extract;

[0062] (2) After the fermentation liquid is centrifuged, the supernatant is collected and freeze-dried to obtain Bifidobacterium longum subsp. longum postbiotics.

[0063] Example 4: Preparation of blood pressure and blood lipid lowering products

[0064] The Bifidobacterium longum subsp. longum postbiotics, natto extract and mulberry leaf extract prepared in Example 2 were mixed in a ratio of 1:1:1 to obtain a product for lowering blood pressure and blood lipids.

[0065] The preparation method of the mulberry leaf extract is as follows: mulberry leaves and water are mixed in a mass ratio of 1:20, heated and refluxed for extraction for 3 times, the extraction liquids are combined, filtered and freeze-dried to obtain the mulberry leaf extract;

[0066] The preparation method of natto extract is as follows: Bacillus subtilis seed liquid and Kluyveromyces marxianus seed liquid are mixed in a ratio of 1:1 to obtain a mixed seed liquid, and the number of viable bacteria of Bacillus subtilis and Kluyveromyces marxianus in the mixed seed liquid is adjusted to 1×10 8 cfu / mL, the mixed seed liquid was inoculated into soybean culture medium at 10% (volume ratio), and fermented at 37°C for 48 hours to obtain fermentation liquid. After the fermentation liquid was centrifuged, the supernatant was taken and dried to obtain natto extract. The components of the soybean culture medium were: soybean powder 80g / L, peptone 20g / L, and sucrose 10g / L.

[0067] Comparative Example 1: Preparation of blood pressure and blood lipid lowering products

[0068] The blood pressure and blood lipid lowering product of this comparative example is composed only of the Bifidobacterium longum subsp. longum postbiotics prepared in Example 2.

[0069] Comparative Example 2:

[0070] The blood pressure lowering and blood lipid lowering product of this comparative example is composed of natto extract only.

[0071] Comparative Example 3:

[0072] The blood pressure and blood lipid lowering product of this comparative example is composed of mulberry leaf extract only.

[0073] Comparative Example 4:

[0074] The difference between this comparative example and Example 4 is that during the preparation of the Bifidobacterium longum subsp. longum postbiotics, the fermentation medium does not contain the Sophora japonica flower extract.

[0075] Experimental Example 1: Animal experiment to investigate the blood pressure lowering effect

[0076] Animal experiments were conducted with reference to the journal "Study on the hypotensive mechanism of Lycium barbarum protein hydrolysate in spontaneously hypertensive rats (Tao Yao et al., Food Industry Science and Technology vol.40, No.10, 2019)". The specific steps are as follows:

[0077] SPF healthy male 12-week-old essential hypertensive rats (SHR) with a body weight of 250-300g were selected and fed with basic feed for 7 days at a temperature of 25±2℃, a humidity of 50-60%, 12h alternating light and dark lighting, and free access to water and food.

[0078] SHR rats were randomly divided into 7 groups, 10 rats in each group, including blank group and treatment groups 1-5. The specific treatments of each group were as follows:

[0079] Blank group: intragastric administration of distilled water;

[0080] Probiotic group: intragastric administration of the bacterial precipitate of Bifidobacterium longum subsp. longum prepared in Example 2;

[0081] Treatment group 1: intragastric administration of the blood pressure and blood lipid lowering product solution prepared in Example 4;

[0082] Treatment group 2: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 1

[0083] Treatment group 3: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 2;

[0084] Treatment group 4: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 3;

[0085] Treatment group 5: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 4.

[0086] The blood pressure and blood lipid products solution used in treatment groups 1-5 was prepared by mixing blood pressure and blood lipid products with water at a ratio of 0.001g:1mL. Each group of rats was gavaged once a day in the morning, with each gavage volume of 0.5mL (1g of the probiotic group was considered as 1mL) for 5 consecutive weeks. During the experiment, the conservation measures and feeding management of the rats in each group were guaranteed to be exactly the same.

[0087] During the 1-3 weeks before the experiment, each rat was trained to measure blood pressure for 30 minutes every morning using a non-invasive rat tail blood pressure meter to adapt the animals to the blood pressure monitoring environment. During the 4th to 6th week of the experiment, the rat's tail vein pressure (i.e., systolic blood pressure) was tested at 1 hour every morning, and the average value was taken. The results are shown in Table 1.

[0088] Table 1 Results of rat tail vein pressure test

[0089]

[0090] The present invention uses rats with essential hypertension as experimental subjects, and orally administers blood pressure lowering and blood lipid products to them, and measures the tail vein pressure (i.e., systolic blood pressure) of the rats to reflect the blood pressure lowering effect of each blood pressure lowering and blood lipid product. As can be seen from Table 1, the tail vein pressure of the blank group rats can reach 179.1 mmHg because the blood pressure lowering and blood lipid products were not orally administered, and the bacterial precipitation of Bifidobacterium longum subspecies longum prepared in Example 2 can significantly reduce the tail vein pressure of the rats, which shows that the Bifidobacterium longum subspecies longum screened by the present invention has the effect of lowering blood pressure and blood lipids.

[0091] At the same time, the blood pressure lowering and blood lipid products prepared by the present invention are gavaged, and the tail vein pressure of rats can be reduced to 126.5 mmHg. Although the postbiotics, natto extracts and mulberry leaf extracts are gavaged as blood pressure lowering and blood lipid products for SHR rats, they can have a certain blood pressure lowering effect, but the tail vein pressure of rats is still higher than 145.2 mmHg. It can be seen that the postbiotics, mulberry leaf extracts and natto extracts prepared by the present invention using Bifidobacterium longum subspecies long WZA-BL01 have a synergistic effect in lowering blood pressure. In addition, the present invention can improve the blood pressure lowering effect of the postbiotics prepared by Bifidobacterium longum subspecies long WZA-BL01 by adding Sophora japonica extract to the fermentation medium.

[0092] Test Example 2: Animal experiment to investigate the effect of lowering blood lipids

[0093] The rat animal experiment was conducted according to the experimental method in Chapter 3 of the paper "Preparation of Oat Peptides and Study on Their Effects on Lowering Blood Lipids and Blood Pressure" (Jiangsu University, Ma Chaoyue, 2018). The specific steps are as follows:

[0094] SPF male SD rats, 6 weeks old, weighing 120±20g, were selected and fed with basic feed for 7 days. The feeding temperature was 22±2℃, the humidity was 40-70%, the light was alternating between light and dark for 12h, and the rats had free access to food and water.

[0095] Ten rats were randomly selected as the blank group and gavaged with 1mL / 100g (body weight) of normal saline daily. The rest of the rats were gavaged with 1mL / 100g (body weight) of high-fat emulsion daily, once a day, for a total of 60 days. At the same time, each group of rats was guaranteed to be supplied with drinking water and basic feed every day. Among them, the high-fat emulsion was prepared by mixing sucrose, lard, egg yolk, cholesterol, sodium cholate and basic feed in a mass ratio of 10:12:10:1:0.5:66.5. After the last gavage, the rats in each group fasted for 12h and could not be deprived of water. 1.5mL of blood was collected from the orbital venous plexus to measure TG, TC, HDL-C and LDL-C to reflect the blood lipid levels of the rats. When the blood lipid levels of the experimental group rats were significantly different from those of the blank group, the model was successfully established.

[0096] The SD rats with successful modeling were selected and randomly divided into 7 groups, 10 rats in each group, namely the model group, treatment groups 1-5 and the positive control group. The treatments of each group were as follows:

[0097] Blank group: intragastric administration of distilled water;

[0098] Probiotic group: intragastric administration of Bifidobacterium longum subsp. longum bacterial precipitate prepared in Example 2;

[0099] Treatment group 1: intragastric administration of the blood pressure and blood lipid lowering product solution prepared in Example 4;

[0100] Treatment group 2: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 1

[0101] Treatment group 3: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 2;

[0102] Treatment group 4: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 3;

[0103] Treatment group 5: intragastric administration of the blood pressure lowering and blood lipid product solution prepared in comparative example 4;

[0104] The blood pressure lowering and blood lipid product solutions used in each treatment group were prepared by mixing blood pressure and blood lipid products with water at a ratio of 0.001g:1mL. Each group of rats was gavaged once a day in the morning, with each gavage volume of 0.5mL (1g in the probiotic group was considered as 1mL) for 30 consecutive days. During the experiment, each group of rats was given a high-fat emulsion to ensure that the conservation measures and feeding management of each group of rats were exactly the same.

[0105] After the last oral gavage, rats in each group were fasted for 12 h, but not water, and anesthetized with 10% chloral hydrate at 400 mg / kg (body weight). 5 mL of whole blood was collected from the abdominal aorta and allowed to stand at room temperature until the blood coagulated naturally. The blood was centrifuged (3500 rpm, 10 min, 4°C) and the supernatant was taken as serum. Total cholesterol TC, triglyceride TG, high-density lipoprotein HDL-C, and low-density lipoprotein LDL-C in the serum were measured. The results are shown in Table 2.

[0106] Table 2 Blood lipid levels in the serum of rats in each group

[0107]

[0108] It can be seen from Table 2 that compared with the blank control group, the total cholesterol, triglyceride and low-density lipoprotein contents in the probiotic group were significantly reduced, and the high-density lipoprotein content was significantly increased. This shows that the long subspecies of Bifidobacterium longum screened by the present invention has the effect of lowering blood pressure and blood lipids.

[0109] At the same time, compared with the model group, the blood pressure lowering and blood lipid products prepared by the present invention can effectively reduce the content of total cholesterol, triglycerides and low-density lipoprotein in serum, and increase the content of high-density lipoprotein, while comparative examples 1-3 respectively use postbiotics, natto extracts and mulberry leaf extracts as blood pressure lowering and blood lipid products, and the content of total cholesterol, triglycerides and low-density lipoprotein is still higher than the content of the above indicators in the corresponding serum of the product prepared in Example 4, while the content of high-density lipoprotein is lower than the content in the corresponding serum of the product prepared in Example 4. It can be seen that the postbiotics, mulberry leaf extracts and natto extracts prepared by the present invention using Bifidobacterium longum subspecies long WZA-BL01 have a synergistic effect in lowering blood lipids. In addition, the present invention can improve the blood lipid-lowering effect of the postbiotics prepared by Bifidobacterium longum subspecies long WZA-BL01 by adding Sophora japonica extract to the fermentation medium.

[0110] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A strain of Bifidobacterium longum subspecies longum that lowers blood pressure and blood lipids ( Bifidobacterium longum subsp.longum )WZA-BL01, characterized in that, The Bifidobacterium longum subsp. longum ( Bifidobacterium longum subsp.longum )WZA-BL01 was deposited in China Center for Type Culture Collection with the deposit number: CCTCC NO: M 20241531.

2. A Bifidobacterium longum subsp. longum postbiotic, characterized in that Prepared by the following method: (1) inoculating the Bifidobacterium longum subspecies longum described in claim 1 into a fermentation medium, and fermenting at 35-40° C. for 48-72 hours to obtain a fermentation liquid; The inoculation amount of Bifidobacterium longum subspecies longum is 10-20% of the volume of the fermentation medium; The components of the fermentation medium are: peptone 10-20 g / L, glucose 15-25 g / L, yeast extract 1.5-2.5 g / L, soluble starch 0.3-0.6 g / L, sodium chloride 3-6 g / L, L-cysteine ​​0.3-0.6 g / L, tomato extract 3-6 g / L, liver extract 1.5-2.5 g / L, Tween-80 0.5-1.5 mL / L, and Sophora japonica extract 30-50 mg / L. The preparation method of the sophora japonica extract is as follows: after mixing the sophora japonica and water in a solid-liquid ratio of (80-100) g:500 mL, decocting 2-3 times, each decocting time is 2-3 hours, combining the decoctions, and drying to obtain the sophora japonica extract; (2) After the fermentation liquid is centrifuged, the supernatant is collected and dried to obtain Bifidobacterium longum subsp. longum postbiotics.

3. Use of the Bifidobacterium longum subsp. longum described in claim 1 or the Bifidobacterium longum subsp. longum subsp. longum postbiotic described in claim 2 in the preparation of products for lowering blood pressure and blood lipids.

4. The use according to claim 3, characterized in that The blood pressure and blood lipid lowering product is prepared from the Bifidobacterium longum subsp. longum postbiotics according to claim 2, natto extract and mulberry leaf extract in a ratio of 1:1:1; The preparation method of the mulberry leaf extract is as follows: mulberry leaves and water are mixed in a mass ratio of 1:20, heated under reflux and extracted three times, the extracted liquids are combined, filtered and dried to obtain the mulberry leaf extract; The preparation method of the natto extract comprises the following steps: mixing Bacillus subtilis seed liquid and Kluyveromyces marxianus seed liquid in a ratio of 1:1 to obtain a mixed seed liquid, inoculating the mixed seed liquid into a soybean culture medium, fermenting the mixture at 37°C for 48 hours to obtain a fermentation liquid, centrifuging the fermentation liquid, taking the supernatant and drying it to obtain the natto extract.

5. The use according to claim 4, characterized in that The inoculation amount of the mixed seed liquid is 10% of the volume of the soybean culture medium; the components of the soybean culture medium are: soybean powder 80g / L, peptone 20g / L, and sucrose 10g / L.

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