A cholesterol-lowering, gastric acid- and intestinal juice-resistant Bifidobacterium lactis BL-H4P and its domestication and fermentation method, bacterial agent and application

Abstract

The present invention discloses a cholesterol-lowering, gastric acid- and intestinal juice-resistant Bifidobacterium lactis BL-H4P and a taming and fermentation method, a bacterial agent and an application thereof. Bifidobacterium lactis BL-H4P) is deposited with CCTCC NO: M 20221559. The strain was isolated from the intestines of healthy people and domesticated under alcohol stress. It has good tolerance to gastric acid and intestinal fluid. As a cholesterol-lowering probiotic, it has better efficacy and performance. Sequencing analysis found that the strain has no virulence genes, which is a great advantage over the traditional drugs currently used for cholesterol-lowering.

Description

Technical Field

[0001] The invention belongs to the field of microorganisms, and in particular relates to a cholesterol-lowering, gastric acid- and intestinal juice-resistant Bifidobacterium lactis BL-H4P, a domestication and fermentation method, a bacterial agent and an application thereof. Background Art

[0002] Bifidobacterium lactis ( Bifidobacterium lactis ), is a probiotic, commonly known as lactic acid bacteria or lactic acid bifidobacterium, which is a type of bacteria that is beneficial to the human body and is commonly found in fermented foods such as yogurt and lactic acid fermented vegetables. Bifidobacterium lactis mainly includes two main types: Bifidobacterium ragenbergii ( Lactobacillus acidophilus ) and Bifidobacterium buskinii ( Bifidobacterium bifidum These bacteria play an important role in the intestines, supporting the health of the digestive system, maintaining the balance of intestinal flora, helping to prevent the growth of harmful bacteria, promoting the normal function of the immune system, aiding nutrient absorption, relieving digestive discomfort, and having a positive impact on the prevention and treatment of some intestinal diseases.

[0003] Many studies have shown that Bifidobacterium lactis has the effects of lowering serum cholesterol, lowering blood lipids and improving body immunity. For example, Chinese patent application CN112592874A discloses a Lactobacillus acidophilus JYLA-191 and its application for lowering cholesterol content in blood, wherein the Lactobacillus acidophilus JYLA-191 bacteria can combine with cholesterol in the intestine, slow down the absorption of cholesterol, reduce the formation rate of lipoprotein in blood, and reduce the cholesterol content in the circulatory system; another Chinese patent application CN113832058A discloses the application of Bifidobacterium lactis BLa80 in the preparation of drugs or foods for lowering blood lipids and regulating intestinal flora, and mentions that Bifidobacterium lactis BLa80 can be widely used in the field of food and microbial preparations, and can achieve the purpose of regulating intestinal flora and lowering blood lipids through daily intake without the need for drugs.

[0004] Since high cholesterol and high blood lipids are one of the main factors causing cardiovascular diseases such as coronary heart disease, hypertension, and atherosclerosis, traditional drug treatments have certain side effects. As people's health awareness increases, more and more people prefer to reduce serum cholesterol and blood lipids by improving their diets and taking probiotics. Therefore, exploring the cholesterol-lowering and blood lipid-lowering properties of probiotics has become a hot topic in recent years.

[0005] However, before entering the small intestine, Bifidobacterium lactis needs to pass through the environment of gastric acid and gastric juice. Some strains have poor tolerance to gastric acid and lose their activity in the stomach, which affects their further survival in the intestinal juice. Active substances such as trypsin in the intestinal juice will also affect probiotics, resulting in the inhibition of the growth of some strains. Therefore, it is crucial to improve the tolerance of Bifidobacterium lactis, which has the effect of lowering cholesterol, so that it can better adapt to the living environment and obtain better performance in lowering cholesterol. Summary of the invention

[0006] In order to solve the above problems and achieve the above objectives, the present invention provides a cholesterol-lowering gastric acid and intestinal juice-resistant Bifidobacterium lactis BL-H4P ( Bifidobacterium lactis BL-H4P) and its domestication and fermentation method, bacterial agent and application, after isolating the original bacterial strain from the intestine of healthy people and domesticating it, successfully obtains a bacterial strain that is more tolerant to gastric acid and intestinal fluid, which can be used to reduce cholesterol. The specific technical scheme is as follows:

[0007] First, the present invention provides a Bifidobacterium lactis BL-H4P, which was deposited in the China Center for Type Culture Collection (CCTCC) on October 12, 2022, at Wuhan University, Wuhan, China, and is classified and named Bifidobacterium lactis ( Bifidobacterium lactis BL-H4P), the deposit number is CCTCC NO: M 20221559.

[0008] The gene sequence of the aforementioned Bifidobacterium lactis BL-H4P is shown in SEQ NO.1.

[0009] Secondly, the present invention provides a method for taming a cholesterol-lowering, gastric acid- and intestinal juice-resistant Bifidobacterium lactis BL-H4P, wherein an original Bifidobacterium lactis strain isolated from the intestine of a healthy person is placed in an acclimation medium containing a certain concentration of alcohol for multiple rounds of stress culture taming to obtain a cholesterol-lowering, gastric acid- and intestinal juice-resistant strain Bifidobacterium lactis BL-H4P, whose preservation number is CCTCC NO: M 20221559.

[0010] In the aforementioned cholesterol-lowering gastric acid and intestinal juice-resistant Bifidobacterium lactis BL-H4P domestication method, the alcohol volume fraction concentration in the domestication medium is 4% to 8%.

[0011] The aforementioned cholesterol-lowering gastric acid and intestinal juice-resistant Bifidobacterium lactis BL-H4P domestication method comprises the following steps: the domestication medium is a glucose-lowering MRS broth medium, the sugar content of which is 20% of the original medium, and the pH is adjusted to 6.0, while the other components remain unchanged.

[0012] The above-mentioned cholesterol-lowering gastric acid and intestinal juice resistant Bifidobacterium lactis BL-H4P acclimation method, the Bifidobacterium lactis culture medium components include: glucose 23g / L, yeast extract powder 10g / L, yeast peptone 10g / L, soy peptone 10g / L, oligogalactose 5g / L, anhydrous sodium acetate 5g / L, Tween 80 1g / L, diammonium hydrogen citrate 2g / L, dipotassium hydrogen phosphate 2g / L, magnesium sulfate heptahydrate 0.2g / L, manganese sulfate monohydrate 0.04g / L, L-cysteine ​​hydrochloride 1g / L, the balance is purified water, the pH is adjusted to 7.1±0.1, and sterilized at 115°C for 30min.

[0013] The above-mentioned cholesterol-lowering gastric acid and intestinal juice resistant Bifidobacterium lactis BL-H4P domestication method comprises five rounds of domestication, and the domestication culture method comprises: inoculating the bacteria in the logarithmic growth phase into the domestication medium containing alcohol, marking it, and placing it in a static culture at the optimal temperature for the bacteria for 24 to 48 hours; after each round of alcohol stress, measuring the OD of the bacterial solution 600 The value was measured to determine the activity of the bacterial solution, and then the strains were collected for preservation and identification.

[0014] Again, the present invention provides a fermentation method of Bifidobacterium lactis BL-H4P which is cholesterol-lowering and resistant to gastric acid and intestinal fluid, and the method is used to culture and ferment the aforementioned Bifidobacterium lactis BL-H4P; the specific fermentation process is: streaking the glycerol bacteria stored at -80°C on an MRS solid culture medium for recovery, culturing at 37°C for 36 to 48 hours, picking bacteria spots and inoculating them on a Bifidobacterium lactis liquid culture medium for activation treatment, and then culturing at 37°C for 18 to 24 hours, and measuring the OD with an enzyme marker. 600 Then, the fermentation was expanded and the fermentation conditions were as follows: 5 ml was inoculated into 1000 ml of Bifidobacterium lactis liquid culture medium, cultured at 37°C for 12 to 18 hours; and the OD was measured by an enzyme marker 600 value and detect its viable bacteria data.

[0015] In addition, the present invention also provides a bacterial agent, which contains the aforementioned Bifidobacterium lactis BL-H4P.

[0016] Finally, the present invention provides an application of the aforementioned Bifidobacterium lactis BL-H4P, namely, application in the preparation of a cholesterol-lowering preparation.

[0017] Beneficial effects of the present invention:

[0018] 1) The present invention isolates the original strain from the intestine of a healthy person, places it in a manufactured stress environment for domestication, and obtains a new strain of Bifidobacterium lactis H4P ( Bifidobacterium lactis BL-H4P), which has increased the ability to tolerate gastric acid and intestinal fluid, has better efficacy and performance as a cholesterol-lowering probiotic.

[0019] 2) The domestication method of the present invention is the first to use alcohol stimulation to stress domesticate the original bacterial strain, so that the obtained bacterial strain can adapt to the harsh growth environment, increase its tolerance to gastric acid and intestinal fluid, maintain a high activity, and enhance the effect and performance of lowering cholesterol.

[0020] 3) The domestication method of the present invention was carried out for a total of 5 rounds, with obvious domestication effects and better fermentation culture conditions, which created suitable conditions for large-scale fermentation culture of the domesticated strains and was beneficial to later production.

[0021] 4) The strain obtained by domestication in the present invention is derived from the healthy human intestine and has no toxic side effects on the human body. Sequencing analysis found that the strain has no virulence genes, which has great advantages over the traditional drugs currently used for lowering cholesterol. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a picture of the growth of Bifidobacterium lactis BL-H4P on MRS solid medium;

[0023] Figure 2 This is a Gram staining picture of Bifidobacterium lactis BL-H4P of the present invention under an optical microscope. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with embodiments and drawings.

[0025] Culture medium used in the examples:

[0026] MRS solid culture medium: soy peptone 10g, yeast extract powder 12g, glucose 20g, dipotassium hydrogen phosphate 2g, anhydrous sodium acetate 5g, manganese sulfate monohydrate 0.04g, magnesium sulfate heptahydrate 0.2g, Tween-80 1g, beef extract 8g, agar 15g, purified water 1000mL, pH adjusted to 6.5, sterilized at 115℃ for 30min, and set aside.

[0027] MRS broth medium: soy peptone 10g, yeast extract powder 12g, glucose 20g, dipotassium hydrogen phosphate 2g, anhydrous sodium acetate 5g, manganese sulfate monohydrate 0.04g, magnesium sulfate heptahydrate 0.2g, Tween-80 1g, purified water 1000mL, pH adjusted to 6.5, sterilized at 115℃ for 30min, set aside.

[0028] Acclimation medium: 10 g soy peptone, 12 g yeast extract powder, 4 g glucose, 2 g dipotassium hydrogen phosphate, 2 g diammonium hydrogen citrate, 5 g anhydrous sodium acetate, 0.04 g manganese sulfate monohydrate, 0.2 g magnesium sulfate heptahydrate, 1 g Tween-80, 1000 mL purified water, adjust pH to 6.0, sterilize at 115 °C for 30 min, and set aside.

[0029] Bifidobacterium lactis liquid culture medium: 23 g glucose, 10 g yeast extract powder, 10 g yeast peptone, 10 g soy peptone, 5 g galacto-oligosaccharide, 5 g anhydrous sodium acetate, 1 g Tween 80, 2 g diammonium hydrogen citrate, 2 g dipotassium hydrogen phosphate, 0.2 g magnesium sulfate heptahydrate, 0.04 g manganese sulfate monohydrate, 1 g L-cysteine ​​hydrochloride, 1000 mL purified water, adjust pH to 7.1±0.1, sterilize at 115°C for 30 min, and set aside.

[0030] Example 1

[0031] This example is to perform multiple rounds of stress culture and domestication on Bifidobacterium lactis (hereinafter referred to as the original strain, codenamed BL-C01) isolated from the intestines of healthy people to obtain the cholesterol-lowering strain Bifidobacterium lactis BL-H4P ( Bifidobacterium lactis BL-H4P). The specific method is as follows:

[0032] 1. Culture medium improvement: The acclimation culture medium is a low-sugar culture medium, that is, the sugar content in the culture medium is reduced to 20% of the sugar content of the original culture medium (the original culture medium is the MRS broth culture medium commonly used for lactic acid bacteria, and the following Table 1 is the acclimation culture medium, which is based on the MRS broth culture medium, and the glucose content in the culture medium is reduced from 20g / L to 20% glucose content (4g / L), and the other components remain unchanged). The pH is adjusted to pH=6.0; at the same time, alcohol is added to the culture medium, and the volume fraction concentration is 4% to 8%; other components remain unchanged. The specific formula is shown in Table 1.

[0033] Table 1. Composition of stress medium

[0034]

[0035] 2. Operation method:

[0036] 1) Prepare the acclimation medium: prepare the medium according to the formula, sterilize it and add alcohol (absolute ethanol). The alcohol concentration in the medium is divided into three gradients: 4%, 6%, and 8%. Dispense into test tubes at a rate of 10 ml per tube.

[0037] 2) The original strain of Bifidobacterium lactis BL-01 isolated from the intestine of a healthy person was inoculated into a fermenter and cultured to the logarithmic growth phase (10 9CFU / ml), take 0.1ml of bacteria and inoculate it into a test tube; repeat 3 tubes for each alcohol concentration. For details, refer to Table 2.

[0038] Table 2. Alcohol concentration in culture medium and experimental design

[0039]

[0040] 3) Mark each test tube and culture it statically at the optimal temperature for Bifidobacterium lactis (37°C) for 24 hours to carry out the first alcohol stress culture. If the growth is too slow, the time can be extended, generally 42 to 48 hours is the most suitable.

[0041] 4) The original strain after the first alcohol stress culture was transferred to a new culture medium, the culture medium and alcohol concentration remained unchanged, and the culture and domestication were continued under the same conditions as step 3);

[0042] 5) Repeat step 4) four times for a total of 5 rounds of acclimatization (A, B, C, D, E), and then collect the strains for identification (sequencing). 600 The values ​​are shown in Table 3.

[0043] Table 3. OD of strains after five rounds of acclimatization 600 value

[0044]

[0045] After the E round of acclimation, since the strains no longer grow in the medium with 8% alcohol concentration, the strains in three test tubes of 4% and 6% formulas were identified and preserved. Specifically, 50% glycerol and bacterial solution were added to the cryopreservation tubes in a ratio of 1:1 and stored at -80℃.

[0046] Example 2

[0047] This example explores the fermentation conditions of the domesticated strain in Example 1 and tests the number of viable bacteria in the fermentation product. The details are as follows:

[0048] In this embodiment, the components of the liquid culture medium for Bifidobacterium lactis are as follows: 23 g of glucose, 10 g of yeast extract powder, 10 g of yeast peptone, 10 g of soy peptone, 5 g of galacto-oligosaccharide, 5 g of anhydrous sodium acetate, 1 g of Tween 80, 2 g of diammonium hydrogen citrate, 2 g of dipotassium hydrogen phosphate, 0.2 g of MgSO47H2O, 0.04 g of MnSO4, 1 g of L-cysteine ​​hydrochloride, 1000 mL of purified water, the pH is adjusted to 7.1±0.1, sterilized at 115°C for 30 min, and set aside.

[0049] Resuscitate the preserved bacteria, use a sterile inoculation loop to take a small amount of the preserved glycerol bacteria, and purify it by streaking on MRS solid medium. Figure 1After culturing at 37℃ for 42h, pick bacteria spots with a sterile inoculation loop and inoculate them in 10ml of Bifidobacterium lactis liquid culture medium for activation treatment. Cultivate at 37℃ for 24h. When the test tube becomes turbid, measure its OD with an enzyme marker 600 Then, 5 ml of the culture medium was taken from each test tube and inoculated into 1000 ml of liquid culture medium of Bifidobacterium lactis for expansion culture and cultured at 37°C for 16 h. After the culture was completed, the bacterial liquid was taken for Gram staining. Figure 2 Then the OD was measured by microplate reader 600 The results are shown in Table 4.

[0050] Table 4. Results of fermentation activity test of domesticated strains

[0051]

[0052] At the same time, the original strain before domestication (with the deposit number BL-C01) was cultured and the relevant data were determined using the same method as above. The experiment was divided into two parallel groups, A and B. The measured data results are shown in Table 5.

[0053] Table 5. Results of fermentation activity test of strains before acclimation

[0054]

[0055] It can be seen from the data in Tables 4 and 5 that the strains domesticated by 4% alcohol concentration stimulation are superior to the strains domesticated by 6% concentration stimulation both in terms of test tube and shake flask levels. The live bacteria data in shake flasks are about 40% higher and about 70% higher than the live bacteria data of the original strain (deposit number BL-C01).

[0056] Therefore, the shake flask activity after 4% alcohol stimulation was selected as 2.9×10 9 The strains in the shake flask were inoculated with 50% of the liquid volume and the fermentation experiment was carried out in a 30L fermenter. The fermentation parameters were temperature 37°C, nitrogen culture, initial pH 7.1, constant pH 6.5, and 20% sodium hydroxide was used to adjust the pH of the fermentation liquid. The speed was 100 rpm to verify its fermentation level. The fermentation time, temperature and viable bacteria value are shown in Table 6.

[0057] Table 6. Fermentation level and activity test results of bacteria after 4% alcohol stimulation and acclimatization Unit: CFU / ml

[0058]

[0059] At the same time, the activity of 8.6×10 8The original bacteria shake flask was filled with 50% of the liquid, and the fermentation experiment was carried out in a 30L fermenter for comparative verification. The fermentation time, temperature and viable bacteria value are shown in Table 7.

[0060] Table 7. Fermentation level and activity test results of original strains Unit: CFU / ml

[0061]

[0062] From the data in Tables 6 and 7, it can be seen that the highest activity of the strain after 4% alcohol stimulation in the fermentation tank for 7 hours is 2.2 times that of the original strain. Therefore, it can be determined that the optimal result of the acclimation experiment is the strain stimulated by 4% alcohol concentration in the acclimation E round, named Bifidobacterium lactis BL-H4P ( Bifidobacterium lactis BL-H4P). The strain was added to a cryopreservation tube with 50% glycerol and bacterial solution in a ratio of 1:1, and refrigerated and transported to China Center for Type Culture Collection (CCTCC), address: Wuhan University, Wuhan, China, with a collection number of CCTCC NO: M 20221559. At the same time, it was transported to Sangon Biotech (Shanghai) Co., Ltd. for sequencing (16S rRNA sequencing), and its genome sequence was obtained as shown in SEQ NO.1, a total of 1394bp.

[0063]

[0064] Example 3

[0065] This example is to investigate the gastric acid and bile salt resistance of the Bifidobacterium lactis BL-H4P obtained in Example 2.

[0066] Test of acid and bile resistance of Bifidobacterium lactis BL-H4P:

[0067] The activity after acclimation to 4% alcohol stimulation in Example 2 was 2.9×10 9 CFU / ml shake flask, inoculated with 10% inoculum into modified MRS broth medium with pH values ​​of 2.0, 2.5, 3.0, 3.5, and 4.0, respectively, and cultured anaerobically at 37°C. Samples were taken at 0h, 2h, and 4h for viable counts. Conventional MRS broth medium was used as the control group. The results are shown in Table 8.

[0068] Table 8. Number of viable cells of Bifidobacterium lactis BL-H4P at different pH values ​​(×10 9 CFU / ml)

[0069]

[0070] Similarly, the strain was inoculated into a modified MRS liquid medium with a pig bile salt mass concentration of 0.1%, 0.3%, and 0.6% at a 1% inoculation rate, and cultured anaerobically at 37°C. Samples were taken at 0h, 2h, 4h, and 6h for viable bacterial counts. Conventional MRS broth culture medium was used as a control group. The results are shown in Table 9.

[0071] Table 9. Number of viable bacteria of Bifidobacterium lactis BL-H4P in the culture medium under different pig bile salt concentrations (×10 9 CFU / ml)

[0072]

[0073] The results shown in Tables 8 and 9 demonstrate that the Bifidobacterium lactis BL-H4P of the present invention has higher acid resistance and bile salt resistance.

[0074] Example 4

[0075] This example is to investigate the cholesterol-lowering ability of Bifidobacterium lactis BL-H4P obtained in Example 2.

[0076] In this example, mice are used as experimental subjects, and the specific experiments are as follows:

[0077] (1) Experimental groups and feeding methods:

[0078] Take the cultured Bifidobacterium lactis BL-H4P, wash it three times with physiological saline, and adjust the concentration to 1.0×109 CFU / mL was used for the mouse gavage test. Thirty 8-week-old BALB / c mice were redivided into three groups according to the average body weight of each group: normal group: fed with basic feed, control group: fed with high-fat feed + normal saline, experimental group: fed with high-fat feed + Bifidobacterium lactis BL-H4P, 10 mice in each group. Each mouse was gavaged with 1mL / day for 14 consecutive days.

[0079] (2) Determination of TC, TG, and HDL-C levels in serum:

[0080] Mice were fasted for 12 hours after oral administration for 14 days, and blood was collected and centrifuged at 2500r / min for 10 minutes to obtain serum. The contents of TC, TG and HDL-C in serum were determined by microplate reader according to the instructions of the kit, and the differences in serum indicators among the groups were compared.

[0081] (3) Data processing:

[0082] SPSS 26 statistical software was used to analyze the data. ANOVA was used to test the significance, and the least significant difference (LSD) test was used for multiple comparisons.

[0083] (4) Analysis of the results of Bifidobacterium lactis BL-H4P lowering serum cholesterol in mice: The results are shown in Table 10.

[0084] Table 10. Effects of Bifidobacterium lactis BL-H4P on serum TC, TG, and HDL-C in mice (mmol / L)

[0085]

[0086] As can be seen from the results in Table 10, compared with the normal group, the serum TC levels of the mice fed with high-fat diet for 14 days in the control group and the experimental group were significantly increased, and the level of the experimental group was significantly lower than that in the control group; there was no significant difference in the serum TG content between the experimental group and the control group, while the level of the control group was significantly increased; the serum HDL-C content of the control group and the experimental group was significantly higher than that of the normal group, while the difference between the two groups was not significant. The serum TC, TG and HDL-C in the experimental group of mice fed with high-fat diet + Bifidobacterium lactis BL-H4P were reduced by 35.7%, 27.1% and 11% respectively compared with the control group, indicating that Bifidobacterium lactis BL-H4P can significantly reduce the serum cholesterol level of mice.

[0087] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view. In addition, it should be understood that although this specification is described in accordance with the implementation mode, it does not include only one technical solution. This narrative mode of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in the embodiments can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A Bifidobacterium lactis BL-H4P, characterized in that: The Bifidobacterium lactis BL-H4P (Bifidobacterium lactis BL-H4P) is deposited in the China Center for Type Culture Collection on October 12, 2022, and the deposit number is CCTCC NO: M 20221559.

2. The Bifidobacterium lactis BL-H4P according to claim 1, characterized in that: Its 16S rRNA sequence is shown in SEQ NO.

1.

3. A fermentation method of Bifidobacterium lactis BL-H4P which is resistant to gastric acid and intestinal juice and lowers cholesterol, characterized in that: The method is used for culturing and fermenting the Bifidobacterium lactis BL-H4P according to claim 1 or 2, and the specific fermentation process is: The glycerol bacteria stored at -80°C were streaked and inoculated on MRS solid culture medium for recovery. After culturing at 37°C for 36-48 hours, bacterial spots were picked and inoculated on the culture medium for activation treatment. The culture medium components included: 23 g / L glucose, 10 g / L yeast extract powder, 10 g / L yeast peptone, 10 g / L soy peptone, 5 g / L galacto-oligosaccharide, 5 g / L anhydrous sodium acetate, 1 g / L Tween 80, 2 g / L diammonium hydrogen citrate, 2 g / L dipotassium hydrogen phosphate, 0.2 g / L magnesium sulfate heptahydrate, 0.04 g / L manganese sulfate monohydrate, 1 g / L L-cysteine ​​hydrochloride, and the balance was purified water. The pH was adjusted to 7.1±0.1 and sterilized at 115°C for 30 minutes. The culture was then incubated at 37°C for 18-24 hours and the OD was measured using an enzyme marker. 600 Then, the fermentation was expanded and the fermentation conditions were as follows: 5 ml was inoculated into 1000 ml of Bifidobacterium lactis liquid culture medium, cultured at 37°C for 12 to 18 hours; and the OD was measured by an enzyme marker 600 value and detect its viable bacteria data.

4. A bacterial agent, characterized in that: The bacterial agent contains the Bifidobacterium lactis BL-H4P according to claim 1 or 2.

5. Use of the Bifidobacterium lactis BL-H4P according to claim 1 or 2 in the preparation of a cholesterol-lowering preparation.

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