Lactobacillus paracasei 1A74 and application of lactobacillus paracasei 1A74 in blood glucose reduction

Abstract

The invention relates to the technical field of microorganisms, in particular to lactobacillus paracasei 1A74 and application of the lactobacillus paracasei 1A74 in reducing blood sugar. Compared with other lactic acid bacteria, the lactobacillus paracasei strain and a microbial agent have the advantages that fermented supernate (CFS) and cell disruption matter supernate (CFE) both have an inhibition effect on alpha-glucosidase and dipeptidyl peptidase IV, and the lactobacillus paracasei strain and the microbial agent have the inhibition effect on the alpha-glucosidase and the dipeptidyl peptidase IV; compared with other lactic acid bacteria strains, the lactic acid bacteria strain has a better hypoglycemic effect than other lactic acid bacteria strains, the bacterial strain is used for preparing buffalo fermented milk, the texture of the fermented milk can be remarkably improved through synergistic interaction with a leavening agent, and the siraitia grosvenorii fermented milk beverage prepared from the bacterial strain can remarkably improve the alpha-glucosidase inhibition rate and the oxidation resistance of the product. Therefore, the strain provided by the invention is a multi-effect bacterium which can be improved on the whole line in multiple aspects of inhibiting the activity of key enzymes related to blood glucose, improving the texture quality and the like, and has wide popularization and development values.

Description

[Technical field]

[0001] The invention relates to the technical field of microorganisms, in particular to Lactobacillus paracasei 1A74 and application thereof in reducing blood sugar. [Background technology]

[0002] Diabetes is a chronic disease in which the body's insulin secretion is relatively insufficient or absolutely insufficient, resulting in metabolic disorders. Diabetes and its complications seriously threaten people's health and reduce their quality of life. At present, the clinical treatment of diabetes is mainly to control blood sugar by controlling diet and increasing exercise, while appropriately combining oral hypoglycemic drugs according to the different conditions of the patients. Based on the treatment mechanism, the commonly used hypoglycemic drugs in China can be divided into three categories: insulin secretagogues, insulin sensitizers and α-glucosidase inhibitors. Oral hypoglycemic drugs are generally used clinically to treat diabetic patients. However, long-term use of this treatment method is prone to cause some side effects, such as diarrhea, dizziness, nausea, loss of appetite, hypoglycemia and liver damage, which seriously threaten people's health.

[0003] Lactic acid bacteria (LAB) are a type of bacteria that use carbohydrates as substrates and can decompose lactose into lactic acid through a fermentation process. The prior art shows that some lactic acid bacteria have been proven to improve diabetes to a certain extent. However, we found in actual research work that due to the complexity of lactic acid bacteria and the huge variety of strains, different lactic acid bacteria strains have different effects on hypoglycemia due to the influence of physiological characteristics. Some strains of the same species have hypoglycemic effects, while some strains do not have the same characteristics. Therefore, in order to enrich germplasm resources and separate and optimize superior hypoglycemic strains, it is necessary to continuously screen, separate, and identify lactic acid bacteria to obtain strains with better hypoglycemic effects. [Summary of the invention]

[0004] In view of the above, in order to enrich germplasm resources and isolate and optimize superior blood sugar-lowering strains, it is necessary to continuously screen, isolate and identify lactic acid bacteria to obtain strains with better blood sugar-lowering effects.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] Lacticaseibacillus paracasei 1A74 has a preservation number of GDMCCNO.64787 and is preserved at: Guangdong Provincial Microbiological Culture Collection Center, address: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou City, and the preservation date is June 24, 2024.

[0007] The present invention also includes a bacterial agent comprising the Lactobacillus paracasei strain 1A74.

[0008] The present invention also includes the use of the Lacticaseibacillus paracasei 1A74 or the bacterial agent containing the Lacticaseibacillus paracasei 1A74 in the preparation of a hypoglycemic drug.

[0009] The present invention also includes the use of the Lacticasei bacillus paracasei 1A74 or the bacterial agent containing the Lacticasei bacillus paracasei 1A74 in preparing buffalo fermented milk and / or preparing monk fruit fermented milk beverage.

[0010] Furthermore, the raw materials of the buffalo fermented milk include 0.3% by mass of Lactobacillus paracasei 1A74 and raw buffalo milk, 7% by mass of white sugar and 0.006% by mass of a starter, wherein the starter consists of Lactobacillus delbrueckii subsp bulgaricus and Sireptococcus salivarius subsp thermophilus, and is purchased from Chr. Hansen.

[0011] Furthermore, the raw materials of the buffalo fermented milk include 0.02-0.06% mogroside by mass, 0.004-0.008% starter by mass, and 0.05-0.010% Lacticaseibacillus paracasei 1A74 by mass, wherein the starter consists of Lactobacillus delbrueckii subsp bulgaricus and Sireptococcus salivarius subsp thermophilus, and is purchased from Chr. Hansen.

[0012] The present invention has the following beneficial effects:

[0013] The Lactobacillus paracasei strain (Lacticaseibacillus paracasei) 1A74 and the bacterial agent of the present invention are relative to other lactic acid bacteria, and their fermentation supernatant (CFS) and cell disruption supernatant (CFE) have inhibitory effects on α-glucosidase and dipeptidyl peptidase IV, and the hypoglycemic effect is better than that of other lactic acid bacteria strains. The strain is used to prepare buffalo fermented milk, which can synergize with the fermentation agent to significantly improve the texture of the fermented milk, and the monk fruit fermented milk beverage prepared by the strain can significantly improve the product α-glucosidase inhibition rate and antioxidant properties. Therefore, the strain of the present application is a multifunctional bacterium that can be fully improved in many aspects such as inhibiting the key enzyme activity related to blood sugar and improving the quality of the texture, and has a wide range of promotion and development value.

Brief Description of the Drawings

[0014] Figure 1 This is a plate image of the strain.

[0015] Figure 2 This is a microscopic examination of the strain. [Specific implementation method]

[0016] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0017] Any feature disclosed in this specification (including any appended claims and abstract), unless otherwise stated, is merely an example of a series of equivalent or similar features.

[0018] The materials, reagents and instruments used in the examples of this application are as follows:

[0019] Example 1

[0020] Identification of strain Lactobacillus paracasei 1A74:

[0021] 1. Morphological classification of strains

[0022] The strain 1A74 of the present application was inoculated into MRS medium and cultured at 37°C for 24 hours, and the colony morphology was observed and recorded. Figure 1 and Figure 2 As shown, the colony morphology of the strain is smooth, round, with neat edges and pale white color. Under the microscope, it appears as a long rod, arranged singly or in pairs.

[0023] 2. Molecular Biology Identification

[0024] The genes of the strain were extracted, amplified and sequenced, and the sequencing results were then submitted to the GenBank database for comparison. Based on the comparison results and combined with the results of colony and bacterial morphology identification, the strain 1A74 was identified as Lacticaseibacillus paracasei 1A74.

[0025] The above-mentioned strain is preserved, and the specific preservation information is: Lactobacillus paracasei strain (Lacticaseibacillus paracasei) 1A74, its preservation number is GDMCC NO.64787, and it is preserved in: Guangdong Provincial Microbiological Culture Collection Center, address: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou City, and the preservation date is June 24, 2024.

[0026] Example 2

[0027] Screening and functional verification of strain Lactobacillus paracasei 1A74:

[0028] 1. Experimental plan for strain screening:

[0029] (1) Activation of strains: 70 strains of lactic acid bacteria frozen at -80°C were inoculated into MRS broth at a 2% inoculation rate and cultured at 37°C for 24 h. The culture was continued for 2 generations. After 18 h of the third generation, the bacterial culture was collected for later use.

[0030] (2) Sample preparation:

[0031] ① Preparation of fermentation supernatant (CFS): Centrifuge the activated bacterial solution at 4℃ and 8000r / min for 15min, collect the bacteria, wash them twice with sterile PBS, and resuspend them in PBS. Adjust the concentration of the bacterial solution to 1×10 9 CFU / mL, incubated at 37°C for 12 h, centrifuged at 4°C and 8000 r / min for 15 min, collected the supernatant, and filtered through a 0.22 μm water microfiltration membrane to obtain CFS.

[0032] ② Preparation of cell supernatant (CFE): Centrifuge the activated bacterial solution at 4°C, 8000 r / min for 15 min, collect the bacteria, wash them twice with sterile PBS, and resuspend them in PBS. Adjust the concentration of the bacterial solution to 1×10 9 CFU / mL, ultrasonically broken under ice bath conditions. Ultrasonic breaking conditions: power 200W, work 3s and stop 5s, breaking 15min. The ultrasonic broken liquid was centrifuged at 4℃ and 12000r / min for 15min, the supernatant was collected, and filtered through a 0.22μm water microfiltration membrane to obtain CFE.

[0033] (3) Screening of lactic acid bacteria with hypoglycemic function:

[0034] ① Screening of lactic acid bacteria with inhibitory effect on α-glucosidase: PNPG method. Add 25μL PBS buffer, 25μL PNPG (20mmol / L) and 25μL sample to a 96-well plate, add 50μL α-glucosidase (0.2U / mL) after 10min at 37℃, add 100μL 0.1mol / L Na2CO3 solution after 15min at 37℃ to terminate the reaction, and detect the absorbance (A) of the reaction solution at a wavelength of 405nm with an enzyme marker. Acarbose is used as the positive control, and the inhibition rate is calculated as shown in the following formula.

[0035]

[0036] In the formula: A represents PBS+PNPG+sample+enzyme+Na2CO3; B represents PBS+PNPG+sample+PBS+Na2CO3; C represents PBS+PNPG+PBS+enzyme+Na2CO3; D represents PBS+PNPG+PBS+PBS+Na2CO3.

[0037] ② Screening of lactic acid bacteria with DPP-Ⅳ inhibition: spectrophotometer method. Add 25μL glycyl-prolyl-p-nitrobenzene (0.2mmol / L) and 25μL sample (CFS or CFE) to a 96-well plate; incubate at 37℃ for 10min, add 50μL DPP-Ⅳ (0.01U / L), react at 37℃ for 60min, then add 100μL sodium acetate buffer solution (1mol / L, pH4.0) to terminate the reaction, and use an enzyme reader to detect the absorbance of the reaction solution at a wavelength of 405nm. The inhibition rate is calculated as follows:

[0038]

[0039] In the formula: A: glycyl-prolyl-p-nitrobenzene + sample + DPP-Ⅳ + sodium acetate buffer solution; B: glycyl-prolyl-p-nitrobenzene + sample + Tris-HCl buffer (100mmol / L, pH8.0) + sodium acetate buffer solution; C: glycyl-prolyl-p-nitrobenzene + Tris-HCl buffer (100mmol / L, pH8.0) + DPP-Ⅳ + sodium acetate buffer solution; D: glycyl-prolyl-p-nitrobenzene + Tris-HCl buffer (100mmol / L, pH8.0) + Tris-HCl buffer (100mmol / L, pH8.0) + sodium acetate buffer solution.

[0040] (4) Determination of the quality of lactic acid bacteria fermented milk with hypoglycemic function

[0041] ① Determination of the number of viable bacteria and pH value of fermented milk: Determination of the number of viable bacteria. Refer to the national standard GB / T4789.2-2022 for counting colony forming units. The screened lactic acid bacteria with hypoglycemic function (i.e. hypoglycemic lactic acid bacteria) strains are inoculated into 12% sterile skim milk at an inoculation rate of 2%, and fermented and cultured at 37°C for 24 hours. Take the fermented milk suspension and dilute it appropriately, spread the diluted bacterial solution on MRS solid culture medium, invert and culture at 37°C for 24-48 hours, and then count. Determination of pH value. Use a pH meter to measure in parallel 3 times.

[0042] ② Determination of fermented milk texture: After the bacterial liquid is taken out of the 4℃ refrigerator and restored to room temperature, the texture analysis is performed using the FTC professional research-level food physical property analyzer to measure the hardness, stickiness and chewiness of the sample. The measurement parameters are as follows: a cylindrical probe with a diameter of 25.60mm and a height of 35.07mm, a detection speed of 60mm / min, a deformation percentage of 20%, a starting force of 0.05N, and a force sensing unit range of 50N.

[0043] 2. Experimental strains used in this application:

[0044] Table 1 Sources of experimental strains

[0045]

[0046]

[0047] 3. Experimental results and analysis:

[0048] Related studies have shown that lactic acid bacteria fermentation supernatant (Cell-free supernatant, CFS) and intracellular cell-free extracts (Intracellular cell-free extracts, CFE) generally contain lipids, protein enzymes, polysaccharides, organic acids and other substances. In the pathogenesis of diabetes, the body's oxidative damage and antioxidant capacity play a very important role. The antioxidant activity of lactic acid bacteria has been confirmed in both in vivo and in vitro experiments. Its antioxidant effect mainly comes from the bioactive components in CFS and CFE. Therefore, this experiment uses these two components as screening samples.

[0049] (1) Screening of lactic acid bacteria with inhibitory effects on α-glucosidase: α-glucosidase is a digestive enzyme that is mainly present in the small intestinal mucosal cells. Its function is to hydrolyze starch and glucose polysaccharides into monosaccharides (glucose) or oligosaccharides. By inhibiting the activity of this enzyme, the digestion and absorption of carbohydrates are delayed, thereby slowing down the rate of increase in blood sugar levels. The screening results of lactic acid bacteria with inhibitory effects on α-glucosidase of the strains screened in this application are specifically shown in Table 2:

[0050] Table 2 Screening results of lactic acid bacteria with α-glucosidase inhibition

[0051]

[0052]

[0053] Note: * indicates that both CFS and CFE of the same strain have inhibitory effects.

[0054] As shown in Table 5, 4 lactic acid bacteria CFS showed inhibitory ability to α-glucosidase, and 14 lactic acid bacteria CFE showed inhibitory ability to α-glucosidase. Among these 14 strains, only CFS and CFE of strain 1A74 and strain W196 showed inhibitory ability to α-glucosidase. From the inhibitory ability point of view, strain 1A74 had the best inhibitory effect, with the inhibitory ability of CFS reaching 32.86% and the inhibitory ability of CFE reaching 88.99%, both reaching significant levels (P < 0.05).

[0055] (3) Screening of lactic acid bacteria with DPP-IV inhibition

[0056] Dipeptidyl peptidase IV (DPP-IV) is a serine protease that can hydrolyze glucagon (GLP-1) and enteroamide (GIP) into inactive products, thereby reducing their concentration and activity in the body, while GLP-1 and GIP lower blood sugar levels by activating insulin and inhibiting glucagon, respectively. Therefore, the inhibition of DPP-IV can increase the bioavailability of GLP-1 and GIP, thereby enhancing their hypoglycemic effects. The strains screened in this application are shown in Table 3 for the screening results of DPP-IV inhibitory lactic acid bacteria.

[0057] Table 3 Screening results of lactic acid bacteria with DPP-IV inhibition

[0058]

[0059] As shown in Table 3, a total of 26 lactic acid bacteria strains of CFS showed an inhibitory effect on DPP-IV, and 35 lactic acid bacteria strains of CFE showed an inhibitory effect on DPP-IV. From Table 3, lactic acid bacteria with both CFS and CFE having DPP-IV inhibitory effects were screened, and the results are shown in Table 4:

[0060] Table 4 Screening results of CFS and CFE of lactic acid bacteria with DPP-IV inhibition

[0061]

[0062] Note: Different capital letters indicate significant differences in the same row, and different lowercase letters indicate significant differences in the same column, P < 0.05, same as in the whole text.

[0063] As shown in Table 4, the CFS and CFE of 15 lactic acid bacteria strains showed inhibitory effects on DPP-IV. Combined with the above results, only one strain, strain 1A74, also had an inhibitory effect on α-glucosidase. Therefore, we know that the above strains showed different inhibitory effects on key glucose-lowering enzymes, which may be due to different strains, different metabolic pathways, and different generated products.

[0064] Example 3

[0065] From the experimental results of Example 2, 5 strains of hypoglycemic lactic acid bacteria were selected for further dairy fermentation experiments, as follows: Based on the above research results, 5 strains of lactic acid bacteria with good comprehensive inhibitory effects on DPP-IV and α-glucosidase were comprehensively screened, including 1 strain of Lactobacillus plantarum (K1), 2 strains of Lactobacillus casei (K63, K69), 1 strain of Pediococcus acidilactici (W200), and 1 strain of Lactobacillus paracasei 1A74, and these strains were used in subsequent fermented milk experiments. The inhibitory effects of the preferred strains on key enzymes are detailed in Table 5.

[0066] Table 5 Preferred 5 strains of lactic acid bacteria

[0067]

[0068] Note: - indicates no inhibitory effect.

[0069] (5) Effect of hypoglycemic lactic acid bacteria on the quality of fermented milk: Lactic acid bacteria are often added to fermented milk. Its nutritional function and special physiological activity have attracted great attention. Lactic acid bacteria can not only improve the nutritional value of fermented milk, but also achieve a functional improvement effect of 1+1>2. 0.3% of 5 strains of lactic acid bacteria were selected to prepare fermented buffalo milk with raw buffalo milk, 7% white sugar, and 0.006% starter, and the product quality was evaluated after ripening.

[0070] ① Effect of the number of live bacteria and pH of glucose-lowering lactic acid bacteria fermented milk in Table 5: In terms of the number of live lactic acid bacteria, the number of lactic acid bacteria is one of the main factors affecting the quality of fermented milk, and it plays a pivotal role in promoting human nutrition and physical health. The effects of the lactic acid bacteria screened in this application on the number of live bacteria and pH of fermented milk are shown in Table 6:

[0071] Table 6 Effect of hypoglycemic lactic acid bacteria on the number of viable bacteria and pH of fermented milk

[0072]

[0073] It can be seen from Table 6 that the number of lactic acid bacteria in some fermented milk groups is greater than that in the blank group (8.64Lg CFU / mL), such as the experimental group added with Lactobacillus paracasei 1A74 (8.84Lg CFU / mL) and Lactobacillus casei K63 (8.82Lg CFU / mL), indicating that the probiotics and the starter in some fermented milk groups have a synergistic symbiotic effect, which promotes the growth of lactic acid bacteria, while the number of viable bacteria of some lactic acid bacteria is lower than that of the blank group, indicating that the probiotics and the starter have an inhibitory effect on growth.

[0074] In terms of pH, as shown in Table 6, compared with the blank group, the addition of glucose-lowering lactic acid bacteria reduced the pH of fermented milk, and the decrease in multiple groups was statistically significant (P < 0.05), but the actual difference was not large, with the maximum decrease being only 0.2 values. The addition of glucose-lowering lactic acid bacteria did not cause over-acidification of the fermented milk.

[0075] In summary, adding Lactobacillus paracasei 1A74 and Lactobacillus casei K63 to ferment milk can significantly increase the number of viable bacteria in the fermented milk and reduce the acidity to an acceptable level.

[0076] ② The effects of the sugar-lowering lactic acid bacteria fermented milk texture in Table 5 are shown in Table 7:

[0077] Table 7 Effect of hypoglycemic lactic acid bacteria on the texture of fermented milk

[0078]

[0079] It can be seen from Table 7 that except for Pediococcus acidilactici W200, the hardness of other groups was significantly higher than that of the blank group (P < 0.05), especially the hardness of the fermented milk added with Lactobacillus plantarum K1 and Lactobacillus paracasei 1A74 exceeded 0.640, indicating that the strains and the starter jointly promoted fermentation, increased the number of lactic acid bacteria per unit area to a certain extent, and increased the yield of lactic acid, thereby making the curd more compact and uniform.

[0080] In terms of viscosity, compared with the blank group, the viscosity of fermented milk with added lactic acid bacteria in multiple groups was significantly improved (P < 0.05), and the viscosity of the Lactobacillus paracasei 1A74 group exceeded 0.350N. This may be because lactic acid bacteria and fermentation agents jointly promote the formation of casein gel network structure, making its network structure denser and firmer, thereby increasing viscosity.

[0081] In terms of chewiness, compared with the blank group, the addition of lactic acid bacteria significantly improved the chewiness of the three fermented milks (P < 0.05), with the degree of improvement reaching 20.8-56.25%, among which Lactobacillus paracasei 1A74 had the most obvious effect.

[0082] In summary, we believe that in terms of texture, Lactobacillus paracasei 1A74 significantly improves the texture characteristics of fermented milk.

[0083] Based on Example 1 and Example 2, we concluded that Lactobacillus paracasei 1A74 can be comprehensively improved in many aspects such as inhibiting key enzyme activities and improving texture quality, and is the strain with the most potential promotion and development value in this screening. Therefore, the strain is preserved, optimized and applied.

[0084] Example 4

[0085] This example is to develop a Luo Han Guo flavored 0 sucrose fermented milk beverage using hypoglycemic strains, and the specific scheme is as follows:

[0086] Using high-sweetness and low-calorie mogroside as a sweetener (about 200 to 300 times sweeter than sucrose), compounded with Lactobacillus paracasei 1A74, we developed a 0-sucrose probiotic yogurt, investigated key blood sugar-lowering enzymes, antioxidant indicators and pH changes, and designed and optimized the addition range of key blood sugar-lowering ingredients.

[0087] 1. Design of the amount of mogroside added

[0088] Table 8 Optimization of the amount of mogroside added

[0089]

[0090] As shown in Table 8, when the addition amount of mogroside was 0.02% and 0.10%, the inhibition rate of α-glucosidase was significantly higher than that of other groups (P < 0.05), indicating that there is an optimal addition range for concentration and inhibition effect. The addition amount of mogroside increased the ABTS clearance rate in a dose-increasing manner, indicating that mogroside can effectively scavenge free radicals, but it was not significant in the range of 0.04-0.08% (P > 0.05). Mogroside can significantly reduce the pH of fermented milk (P < 0.05), indicating that it can promote the production of lactic acid bacteria. When the addition amount of mogroside was 0.02-0.08%, the sensory effect was better, especially 0.02% was the highest value. In summary, when the addition amount of mogroside was in the range of 0.02-0.06%, all indicators of milk beverages achieved good results.

[0091] (2) The design results of the amount of leavening agent added are shown in Table 9:

[0092] Table 9 Optimization of fermentation agent addition

[0093]

[0094] As shown in Table 9, the amount of starter added has little effect on the α-glucosidase inhibition rate. The greater the amount of starter added, the more significantly the ABTS clearance rate of the milk beverage can be improved (P < 0.05). There is a statistically significant difference in pH, but the difference in value is not obvious. The sensory effect is most ideal in the range of 0.004-0.008%. In summary, when the amount of starter added is within the range of 0.004-0.008%, all indicators of milk beverages achieve good results.

[0095] (2) The design results of the addition amount of Lactobacillus paracasei 1A74 are shown in Table 10:

[0096] Table 10 Optimization of the amount of Lactobacillus paracasei 1A74 added

[0097]

[0098] As shown in Table 10, the addition of Lactobacillus paracasei 1A74 can improve the inhibitory effect of milk beverages on α-glucosidase, and the greater the addition amount, the more significant the improvement, especially at 0.015% and 0.100%, which is significantly higher than other groups (P < 0.05). The ABTS scavenging rate of milk beverages in the addition amount range of 0.001-0.015% was not significantly different (P > 0.05), and the highest addition amount of 0.100% significantly improved the antioxidant activity of milk beverages, which is speculated to be due to the significant improvement in the ability of high-dose lactic acid bacteria to produce and scavenge free radicals. The pH value of milk beverages in the 0.015% and 0.100% groups was significantly lower than that in other groups, showing the same rule as the α-glucosidase inhibition rate, which may be related to the activity and number of lactic acid bacteria and the hypoglycemic effect. The sensory effect of the 0.001-0.010% addition range was significantly better than that of other groups (P < 0.05). In conclusion, when the Lactobacillus paracasei 1A74 concentration was within the range of 0.05-0.010%, all indicators of dairy beverages achieved good results.

[0099] Conclusion: Considering the quality indexes of milk beverages, the key ingredients for reducing sugar in Luo Han Guo flavored 0-sucrose fermented milk beverages are as follows: 0.02-0.06% of mogroside, 0.004-0.008% of starter, and 0.05-0.010% of Lactobacillus paracasei 1A74. In this ratio, the milk beverage has good sugar-reducing and antioxidant effects and sensory quality.

[0100] In summary, the Lacticaseibacillus paracasei 1A74 strain of the present invention can be comprehensively improved in many aspects such as inhibiting the key enzyme activity related to blood sugar, increasing bacteria and improving texture quality. It is the strain with the most potential promotion and development value in this screening. The present invention also optimizes the process conditions and parameters of the strain to develop a monk fruit flavored 0-sucrose fermented milk beverage. The screening of the strain has obtained a new type of blood sugar-lowering strain, and at the same time, the application of the strain has been strengthened.

[0101] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. Lactobacillus paracasei strain 1A74, characterized in that The deposit number of the strain is GDMCC NO:64787.

2. A bacterial agent comprising the Lactobacillus paracasei 1A74 strain as claimed in claim 1.

3. Application of Lactobacillus paracasei 1A74 as claimed in claim 1 or a bacterial agent comprising Lactobacillus paracasei 1A74 as claimed in claim 2 in the preparation of hypoglycemic drugs.

4. Application of Lactobacillus paracasei 1A74 as claimed in claim 1 or a bacterial agent comprising Lactobacillus paracasei 1A74 as claimed in claim 2 in preparing buffalo fermented milk and / or preparing Momordica grosvenori fermented milk beverage.

5. The use according to claim 4, characterized in that The raw materials of the buffalo fermented milk include 0.3% by mass of Lacticaseibacillus paracasei 1A74 and raw buffalo milk, 7% by mass of white sugar and 0.006% by mass of a starter, wherein the starter consists of Lactobacillus delbrueckii subsp bulgaricus and Sireptococcus salivarius subsp thermophilus.

6. The use according to claim 4, characterized in that The raw materials of the buffalo fermented milk include 0.02-0.06% of mogroside by mass, 0.004-0.008% of a starter by mass, and 0.05-0.010% of Lactobacillus paracasei 1A74 by mass, wherein the starter consists of Lactobacillus delbrueckii subsp bulgaricus and Sireptococcus salivarius subsp thermophilus.

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