Lacticaseibacillus paracasei and postbiotic product prepared therefrom, and use of both

Abstract

The present invention relates to the technical field of microorganisms. Disclosed are lacticaseibacillus paracasei and a postbiotic product prepared therefrom, and a use of both. The present invention provides lacticaseibacillus paracasei (Latin name) YJS05199, which has the preservation number of GDMCC No.63668, and was preserved in Guangdong Microbial Culture Collection Center on 19 July 2023. The present invention further provides a postbiotic prepared by applying the lacticaseibacillus paracasei. The lacticaseibacillus paracasei and the postbiotic prepared therefrom have a bacteriostatic effect, can inhibit the weight gain of a mouse fed with high-fat diets, reduce the adipose tissue weight and the blood glucose concentration, and can remarkably reduce the levels of TG, TC, and LDL-C in serum of the mouse. Thus, the lacticaseibacillus paracasei and the postbiotic prepared therefrom have great application prospects in preparation of products for preventing or treating obesity and related diseases or in preparation of bacteriostatic products.

Description

A strain of Lactobacillus paracasei and its postbiotic products and applications Technical Field

[0001] The present invention relates to the technical field of microorganisms, and in particular to a strain of Lactobacillus paracasei and a postbiotic product and application thereof. Background Art

[0002] Obesity is a chronic metabolic disease caused by multiple factors, including environmental, genetic, and endocrine factors. As living conditions continue to improve, the intake of high-fat and high-sugar foods in the diet increases. This unbalanced diet leads to metabolic disorders in some people and increases the prevalence of obesity. Obesity increases the risk of developing and progressing chronic metabolic and cardiovascular diseases, including diabetes, hypertension, non-alcoholic fatty liver disease, atherosclerosis, and dyslipidemia.

[0003] Obesity is mainly treated through diet control, exercise, oral medication, etc. Those who are extremely overweight may undergo liposuction or gastrointestinal surgery. However, the effects of diet control and exercise are not obvious and require long-term persistence. In addition, improper exercise methods can easily cause joint damage. Oral Western medicine is often accompanied by adverse reactions such as diarrhea and vomiting, and is expensive. Commonly used Western medicines include sibutramine and orlistat. Sibutramine increases the risk of cardiovascular disease, and long-term use of orlistat can cause diseases such as chronic proctitis. Liposuction and gastrointestinal surgery have certain surgical risks, and the effect of liposuction is difficult to maintain, and the cost of surgery is high.

[0004] Probiotics are important microorganisms that regulate the balance of the human intestinal flora and promote digestion. They are safe and non-toxic. As research on probiotics deepens, it has been discovered that not only live bacteria can exert probiotic functions, but also inactivated bacterial cells, components released by dissolution after bacterial death, and bacterial metabolites can also promote health.

[0005] Chinese patent CN114717146A discloses a postbiotic prepared by Lactobacillus paracasei for alleviating fatty liver and obesity and its application. The patent provides a postbiotic prepared by Lactobacillus paracasei CCFM1224, which has the effect of alleviating fatty liver and obesity. It can significantly inhibit weight gain, liver fat accumulation and pathological changes, and serum TC, HDL-C, and CHE levels in mice fed a high-fat diet; significantly improve blood glucose homeostasis in mice fed a high-fat diet; significantly reduce white adipocyte size, maintain the normal morphology of brown fat, and promote the browning of white fat; and effectively reduce the weight of liver and epididymal white adipose tissue in mice fed a high-fat diet. The postbiotic prepared by this has great application prospects in the preparation of products for the prevention and / or treatment of diseases related to fatty liver, obesity, and metabolic disorders.

[0006] Chinese patent CN113322216A discloses a Lactobacillus paracasei B111H and its use in metabolic syndrome. The Lactobacillus paracasei strain has a deposition number of CGMCC No. 22184. The Lactobacillus paracasei strain B111H described in the patent can significantly inhibit lipid accumulation in stem cells, reduce body weight and blood lipid levels, and thereby improve liver steatosis, which is of great significance for alleviating the occurrence of hyperlipidemia, obesity, and fatty liver.

[0007] At present, intestinal microorganisms suitable for treating or preventing obesity and its related diseases still need to be further developed. The postbiotics of probiotics have the advantages of stability, long shelf life and safety. They are more convenient to process, store and transport, and have broad prospects in developing new products with health functions.

[0008] Summary of the Invention

[0009] The present invention aims to provide a strain of Lactobacillus paracasei and a postbiotic product and application thereof. The Lactobacillus paracasei of the present invention has an antibacterial effect on foodborne pathogens and can effectively lower blood lipids and blood sugar. The postbiotics prepared by the strain can effectively inhibit the weight gain of mice fed a high-fat diet and reduce fat weight, serum TC, TG, LDL-C and blood sugar concentration. At the same time, the present invention develops new applications of the Lactobacillus paracasei and the postbiotics thereof.

[0010] Explanation of terms:

[0011] The term "postbiotic" refers to the metabolites of probiotics after processing, including bacterial components and bacterial metabolites. Specifically, it refers to bacterial components that retain the same activity as live bacteria after being processed by heat treatment, physical treatment, high hydrostatic pressure treatment, freeze drying, ultrasonic vibration, etc. The bacterial components include peptidoglycan, wall teichoic acid, lipoteichoic acid, cell wall polysaccharides, and cell surface-related proteins. The bacterial metabolites include enzymes, organic acids, proteins, peptides, and exopolysaccharides.

[0012] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0013] On the one hand, the present invention provides a Lactobacillus paracasei, whose scientific name is Lacticaseibacillus paracasei, whose preservation number is GDMCC No.63668, and which was deposited in Guangdong Provincial Microbial Culture Collection Center on July 19, 2023.

[0014] Specifically, the Lacticaseibacillus paracasei with a deposit number of GDMCC No. 63668 was named Lacticaseibacillus paracasei YJS05199.

[0015] Specifically, the Lactobacillus paracasei YJS05199 was isolated from fermented food in Guizhou. The strain was sequenced, and its 16S rRNA sequence was compared with the nucleic acid sequence in NCBI. After the comparison results were obtained, it was identified as Lactobacillus paracasei.

[0016] More specifically, the bacterium colonies of the Lactobacillus paracasei YJS05199 on MRS solid culture medium are white, smooth, round bacterium colonies. It is a Gram-positive bacterium and a facultative anaerobic bacterium.

[0017] In another aspect, the present invention provides a postbiotic prepared using the above-mentioned Lactobacillus paracasei YJS05199.

[0018] In another aspect, the present invention provides a method for preparing postbiotics, comprising inoculating Lactobacillus paracasei YJS05199 into a fermentation medium to obtain a bacterial liquid, and then performing heat treatment to obtain the postbiotics.

[0019] Preferably, the inoculation amount of the Lactobacillus paracasei YJS05199 is 1-5%.

[0020] Further preferably, the inoculation amount of the Lactobacillus paracasei YJS05199 is 2-3%.

[0021] Preferably, the fermentation medium is a liquid culture medium.

[0022] Preferably, the liquid fermentation medium is selected from one or more of MRS medium and LB medium.

[0023] Further preferably, the liquid fermentation medium is MRS medium.

[0024] Preferably, the culture temperature is 35-37° C., and the culture time is 16-24 h.

[0025] Preferably, the heat treatment condition is pasteurization.

[0026] More preferably, the pasteurization temperature is 62-65° C. and the time is 20-30 minutes.

[0027] Still more preferably, the pasteurization temperature is 65° C. and the time is 30 minutes.

[0028] Preferably, the postbiotics can be prepared into liquid preparations, solid powders, pastes and other dosage forms.

[0029] Specifically, the liquid preparation includes but is not limited to suspensions and oils.

[0030] Specifically, the solid preparations include but are not limited to powders, tablets, capsules, and granules.

[0031] Specifically, the solid preparation is prepared by drying the above-mentioned postbiotics.

[0032] More specifically, the drying includes vacuum freeze drying, spray drying, fluidized bed drying and vacuum drying.

[0033] In another aspect, the present invention provides use of the aforementioned Lactobacillus paracasei or the aforementioned postbiotics in the preparation of a medicament for preventing, treating or assisting in the treatment of obesity and its related diseases.

[0034] Specifically, the obesity-related diseases include obesity, diabetes, hypertension, hyperlipidemia, endocrine disorders, obese cardiomyopathy, fatty liver and arteriosclerosis.

[0035] More specifically, the obesity-related disease is diabetes.

[0036] More specifically, the diabetes includes type 1 diabetes and type 2 diabetes.

[0037] Specifically, the drug contains 2×10 5 -2×10 14 CFU / mL or 2×10 5 -2×10 14 CFU / g of Lactobacillus paracasei, specifically 2×10 5 CFU / mL (CFU / g), 2×10 6 CFU / mL (CFU / g), 2×10 7 CFU / mL (CFU / g), 2×10 8 CFU / mL (CFU / g), 2×10 9 CFU / mL (CFU / g), 2×10 10 CFU / mL (CFU / g), 2×10 11 CFU / mL (CFU / g), 2×10 12 CFU / mL (CFU / g), 2×10 13 CFU / mL (CFU / g), 2×10 14 CFU / mL (CFU / g), etc. Other point values ​​within this numerical range can be selected.

[0038] Specifically, the dosage of the postbiotics in the medicine is not less than 200 mg / kg body weight.

[0039] Specifically, the drug has the effects of lowering blood lipids and blood sugar.

[0040] In another aspect, the present invention provides the use of the above-mentioned Lactobacillus paracasei in the preparation of food, health products or dietary supplements for preventing or assisting in the treatment of obesity and related diseases.

[0041] Preferably, the food includes fermented milk, yogurt, milk powder, pure milk, yogurt, pudding, solid beverage, compressed candy, lactic acid bacteria beverage, lactic acid bacteria fermented soy products and cheese.

[0042] Further preferably, the food may further include conventional food supplements, including but not limited to flavoring agents, binders, disintegrants, lubricants, and antacids.

[0043] Preferably, the food preparation is selected from any one of solid, dairy, solution, powder and suspension products.

[0044] Preferably, the health care product contains 2×10 5 -2×10 14 CFU / mL or 2×10 5 -2×10 14 CFU / g of Lactobacillus paracasei.

[0045] Further preferably, the health care product further comprises conventional excipients for health care products, including but not limited to fillers, flavoring agents, binders, disintegrants, lubricants, antacids and nutritional enhancers.

[0046] More preferably, the health care products include emulsion products, solution products, powder products and solid products.

[0047] In another aspect, the present invention provides a use of the aforementioned Lactobacillus paracasei or the aforementioned postbiotic in the preparation of an antibacterial product.

[0048] Preferably, the antibacterial effect is the inhibition of foodborne pathogens.

[0049] Specifically, the foodborne pathogens include but are not limited to Salmonella, Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus, Enterobacter sakazakii, Listeria monocytogenes, and Shigella.

[0050] More specifically, the Salmonella includes but is not limited to Salmonella typhimurium.

[0051] More specifically, the foodborne pathogens are Salmonella typhimurium, Staphylococcus aureus and Escherichia coli.

[0052] In another aspect, the present invention provides a medicine for preventing, treating or assisting in treating obesity and obesity-related diseases, wherein the medicine comprises the above-mentioned Lactobacillus paracasei or the above-mentioned postbiotics.

[0053] Specifically, the medicine contains 2×10 5 -2×10 14 CFU / mL or 2×10 5 -2×10 14 CFU / g of Lactobacillus paracasei.

[0054] Specifically, the medicine also includes a pharmaceutically acceptable carrier.

[0055] More specifically, the carrier is selected from one or more of an excipient, a stabilizer, a diluent, a binder, a preservative, a lubricant, and a filler.

[0056] Specifically, the excipient is selected from at least one of microcrystalline cellulose, lactose, pregelatinized starch, cyclodextrin, carboxymethyl cellulose, and mannitol.

[0057] Specifically, the stabilizer is selected from at least one of agar, alginic acid, cellulose ether, and carboxymethyl chitosan.

[0058] Specifically, the diluent is selected from at least one of erythritol, mannitol, sorbitol, xylitol, lactose, sucrose, corn starch, potato starch, calcium phosphate, calcium citrate, and crystalline cellulose.

[0059] Specifically, the binder is selected from at least one of ethanol, starch slurry, syrup, hydroxypropyl methylcellulose, sodium carboxymethyl cellulose, sodium alginate, and polyvinyl pyrrolidone.

[0060] Specifically, the preservative is selected from at least one of methylparaben, propylparaben, methylparaben, ethylparaben, propylparaben, chlorobutanol, thimerosal, mercuric cyanide, phenoxyethanol, chlorhexidine, benzoic acid, sodium benzoate, chlorocresol, benzalkonium bromide, benzalkonium chloride, and ethylparaben.

[0061] Specifically, the lubricant is selected from at least one of magnesium stearate, stearic acid, sodium chloride, sodium oleate, sodium lauryl sulfate, and poloxamer.

[0062] Specifically, the filler is selected from at least one of trehalose, lactose, chitosan, starch and dextrin.

[0063] More specifically, the dosage form of the drug is selected from any one of tablets, capsules, oral liquid dosage forms, granules, ointments, suspensions, powders, emulsions, solutions, pills, suppositories, and aerosols.

[0064] In another aspect, the present invention discloses a food, health product or dietary supplement for preventing or assisting in treating obesity and related diseases, wherein the food, health product or dietary supplement comprises the above-mentioned Lactobacillus paracasei or the above-mentioned postbiotics.

[0065] In another aspect, the present invention provides an antibacterial product, comprising the above-mentioned Lactobacillus paracasei or the above-mentioned postbiotic.

[0066] The beneficial effects of the present invention are:

[0067] The present invention provides a strain of Lacticaseibacillus paracasei YJS05199. The strain and the postbiotics prepared from the strain have the following effects:

[0068] (1) The bacteria and its postbiotics have inhibitory effects on a variety of foodborne pathogens (Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli) and can promote host intestinal health;

[0069] (2) It can significantly reduce the weight gain of mice fed a high-fat diet. The average weight gain of the low-dose and high-dose postbiotic groups was reduced by 45.40% and 46.48% respectively compared with the model group;

[0070] (3) It effectively reduced adipose tissue weight in mice fed a high-fat diet, with low and high doses of Lactobacillus paracasei postbiotics decreasing the weight by 47.21% and 53.83% respectively compared with the model group;

[0071] (4) Significantly reduced the levels of serum TG, TC, and LDL-C in mice fed a high-fat diet. Compared with the model group, low and high doses of Lactobacillus paracasei postbiotics reduced TC levels by 27.91% and 32.56%, respectively; TG levels were reduced by 25.17% and 34.83%, respectively; LDL-C levels were reduced by 25.69% and 36.99%, respectively; HDL-C levels were increased by 19.08% and 20.09%, respectively;

[0072] (5) Reduce blood glucose concentration and improve blood glucose homeostasis in mice fed a high-fat diet;

[0073] (6) The preparation method of this bacterial postbiotic is simple and suitable for large-scale production, transportation and storage.

[0074] Lactobacillus paracasei YJS05199 and its postbiotics have great application prospects in the preparation of products with lipid-lowering, blood sugar-lowering and antibacterial functions.

[0075] Preservation Instructions

[0076] Deposit number: GDMCC No.63668;

[0077] Taxonomic nomenclature: Lacticaseibacillus paracasei;

[0078] Deposit date: July 19, 2023;

[0079] Depository: Guangdong Provincial Microbial Culture Collection Center;

[0080] Abbreviation of depository unit: GDMCC;

[0081] Collection address: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 shows the colony morphology of Lactobacillus paracasei YJS05199.

[0083] Figure 2 shows the Gram staining results of Lactobacillus paracasei YJS05199.

[0084] Figure 3 shows the antibacterial effects of Lactobacillus paracasei fermentation supernatant and postbiotics on three foodborne pathogens.

[0085] Figure 4 shows the in vitro cholesterol-lowering effects of Lactobacillus paracasei, fermentation supernatant, and postbiotics.

[0086] Figure 5 shows the weight gain of mice in different groups (*p<0.05, **p<0.01).

[0087] FIG6 shows the adipose tissue weights of mice in different groups (*p<0.05, **p<0.01).

[0088] Figure 7 shows the serum biochemical indicators of mice in different groups: TG (triglyceride), TC (total cholesterol), HDL-C (high-density lipoprotein cholesterol), and LDL-C (low-density lipoprotein cholesterol) (*p<0.05, **p<0.01).

[0089] FIG8 shows the oral glucose tolerance of mice in different groups (*p<0.05, **p<0.01). DETAILED DESCRIPTION

[0090] The present invention will be further described in detail below with reference to specific examples. The following examples are not intended to limit the present invention but are merely intended to illustrate the present invention. The experimental methods used in the following examples are generally based on conventional conditions unless otherwise specified. The materials and reagents used in the following examples are all commercially available unless otherwise specified.

[0091] Basic Example:

[0092] Isolation and purification of Lactobacillus paracasei:

[0093] Aseptically weigh 25 g of sample into 225 mL of sterile saline and vibrate for 5 minutes to prepare a 1:10 sample solution. Then, dilute the solution tenfold to the desired concentration. Spread 200 μL of the dilution evenly onto an MRS plate and incubate at 37°C for 48 hours. Single colonies suspected of being lactic acid bacteria were streaked from the plate and purified three times to achieve uniform colony morphology. Isolates that were Gram-stain positive and H₂O₂ catalase-negative were subjected to molecular identification.

[0094] 16S identification of strains:

[0095] The genome of the strain was extracted and amplified by PCR using universal bacterial 16S rDNA primers. Sequence alignment at NCBI revealed that the strain was Lactobacillus paracasei. The colony morphology of the strain after 24 hours of culture on MRS solid medium is shown in Figure 1, and the Gram stain results are shown in Figure 2.

[0096] Example 1 Preparation of postbiotics of Lactobacillus paracasei YJS05199

[0097] The seed liquid of Lactobacillus paracasei YJS05199 was inoculated into MRS liquid culture medium at a 2% inoculum volume and cultured at 37°C for 16 h.

[0098] The bacterial liquid was heat treated (65° C., 30 min) to obtain postbiotics, which were then concentrated and freeze-dried to obtain postbiotic freeze-dried powder for later use.

[0099] Example 2 Antibacterial Effects of Lactobacillus paracasei Fermentation Broth Supernatant and Postbiotics

[0100] Antimicrobial activity of Lactobacillus paracasei fermentation supernatant and postbiotics using the Oxford cup method

[0101] After activation culture of foodborne pathogens (Salmonella typhimurium, Staphylococcus aureus and Escherichia coli), the bacterial concentration was adjusted to 10 7 CFU / mL, draw 100μL of bacterial liquid onto LB solid medium, use a sterile spreading stick to evenly spread the pathogenic bacteria liquid, and place 3 Oxford cups horizontally on the surface of the solid medium. 200μL of Lactobacillus paracasei supernatant and postbiotics (liquid preparation) were respectively drawn into the wells of the Oxford cups, with MRS medium as the negative control. The plates were placed at 4°C for pre-diffusion for 4 hours, then transferred to a constant temperature incubator for incubation for 12 hours, and the diameter of the inhibition zone was observed and measured. The experiment was repeated 3 times. As shown in Figure 3, the supernatant of Lactobacillus paracasei and postbiotics have inhibitory effects on Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli.

[0102] Example 3 In vitro cholesterol-lowering effect

[0103] The cholesterol-lowering effect of Lactobacillus paracasei cultured in cholesterol medium, as well as the in vitro cholesterol-lowering effect of fermentation supernatant and postbiotics were determined as follows:

[0104] (1) Cholesterol-lowering effect of Lactobacillus paracasei cultured in MRS-CHO medium

[0105] Lactobacillus paracasei was inoculated into MRS-CHO medium (g / L) (0.1 g cholesterol, 2 g ox bile salt, 1 mL Tween, 1 mL glacial acetic acid, 0.12 g sucrose octaacetate) at a 2% (v / v) inoculum, stirred thoroughly, and ultrasonicated in a 60°C water bath for 30 min, added to MRS broth while stirring, and sterilized at 121°C for 20 min. The culture was cultured at 37°C for 48 h, and the culture solution was centrifuged at 4000×g for 10 min. 0.50 mL of the supernatant was added with 3 mL of anhydrous ethanol and 2 mL of 50% KOH, mix thoroughly and place in a 60℃ water bath for 10 minutes, cool to room temperature, add 5mL of n-hexane, vortex and oscillate for 20 seconds, add 3mL of distilled water and let it stand for about 5 minutes to separate, take 2.50mL of the n-hexane layer (upper layer) into a clean test tube, bathe in a 60℃ water bath, blow nitrogen until the solvent is completely evaporated, add 2mL of color developing solution, mix thoroughly, add 1mL of concentrated sulfuric acid, cool and measure the absorbance at OD550.

[0106] The calculation formula is as follows: P0(%)=[(DC) / D]×100%;

[0107] Wherein: P0 represents the cholesterol reduction rate; C: the absorbance of the sample at OD550; D: the absorbance of the blank control (MRS-CHO culture medium) at OD550.

[0108] (2) Cholesterol-lowering effects of fermentation supernatant and postbiotics

[0109] The fermentation supernatant and postbiotics were added to 5 mL of MRS medium containing 100 μg / mL cholesterol at a volume ratio of 1:1, and the cholesterol-lowering rate was determined after shaking at 37°C for 12 h, using the same method as (1).

[0110] The results are shown in FIG4 . Lactobacillus paracasei has a cholesterol-lowering effect when cultured in cholesterol medium, and the fermentation supernatant and postbiotics of the bacteria also have a cholesterol-lowering effect.

[0111] Example 4 Effect of Lactobacillus paracasei postbiotics on weight gain in mice fed a high-fat diet

[0112] Thirty-two 5-week-old healthy male C57BL / 6 mice were randomly divided into 4 groups, with 8 mice in each group. The 4 groups were: normal diet group (control group), high-fat diet feeding model group, low-dose group of Lactobacillus paracasei YJS05199 postbiotic group (H-1 group, 200 mg / kg mouse body weight) and high-dose group of Lactobacillus paracasei YJS05199 postbiotic group (H-2 group, 600 mg / kg mouse body weight).

[0113] After one week of adaptive feeding, the normal diet control group was fed a normal diet, and the other groups were fed a high-fat diet (casein 100g / kg, sucrose 200g / kg, lard 150g / kg, rat and mouse maintenance feed 522g / kg, rat and mouse premix 4g / kg, cholesterol 12g / kg, sodium cholate 2g / kg, calcium bicarbonate (feed grade type 1) 6g / kg, stone powder (calcium carbonate) 4g / kg, basal feed purchased from Guangdong Medical Animal Experimental Center). Postbiotic freeze-dried powder (dissolved in normal saline) was gavaged into the mice at a dose of 0.2mL / mouse / day (400mg / kg BW). The normal diet control group and the model group were gavaged with an equal amount of normal saline as controls. All groups had free access to water and food.

[0114] The mice were weighed at week 1 and week 12 of postbiotic intervention, and the weight gain of the mice is shown in Figure 5. Continuous feeding of a high-fat diet resulted in a significantly higher weight gain in the model group than in the normal diet control group, while the average weight gain in the low- and high-dose postbiotic groups was reduced by 45.40% and 46.48%, respectively, compared to the model group, indicating that Lactobacillus paracasei postbiotics can alleviate weight gain in mice fed a high-fat diet.

[0115] Example 5 Effect of Lactobacillus paracasei postbiotics on fat accumulation in mice fed a high-fat diet

[0116] After the feeding experiment, the mice were bled and sacrificed, and their adipose tissue was collected and weighed. As shown in Figure 6, the model group had the most adipose tissue. Both low and high doses of Lactobacillus paracasei postbiotics significantly inhibited fat gain in mice fed a high-fat diet, decreasing fat by 47.21% and 53.83%, respectively, compared to the model group.

[0117] Example 6 Effects of Lactobacillus paracasei postbiotics on serum biochemical parameters in mice fed a high-fat diet

[0118] After the mice were raised, blood was collected and the mice were sacrificed. The whole blood was centrifuged (2500 rpm for 15 minutes) to obtain serum. Serum parameters, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C), were measured using an automated biochemical analyzer. The results are shown in Figure 7.

[0119] Both low- and high-dose Lactobacillus paracasei postbiotics reduced serum TC levels in mice fed a high-fat diet, by 27.91% and 32.56% compared to the model group, respectively. TG levels were reduced by 25.17% and 34.83% in the low- and high-dose intervention groups, respectively, compared to the model group. LDL-C levels were also reduced by 25.69% and 36.99% in the low- and high-dose intervention groups, respectively, compared to the model group. Both low- and high-dose postbiotics significantly protected against the decrease in serum HDL-C in mice induced by a high-fat diet, with increases of 19.08% and 20.09% in the low- and high-dose groups, respectively, compared to the model group. These results suggest that Lactobacillus paracasei postbiotics have cholesterol-lowering and lipid-lowering effects, potentially helping to alleviate obesity.

[0120] Example 7 Effect of Lactobacillus paracasei postbiotics on blood glucose homeostasis in mice fed a high-fat diet

[0121] Before the end of the feeding experiment, an oral glucose tolerance test was performed to assess blood glucose homeostasis in mice. After fasting for 12 hours, mice were gavaged with 20% glucose solution at a dose of 2 mg / g body weight. Blood was collected from the tail vein before gavage (0 min) and 15, 30, 60, 90, and 120 min after gavage for measurement of blood glucose levels.

[0122] As shown in Figure 8, before oral administration of glucose solution, the fasting blood glucose value of the model group was 9.03 mmol / L. The fasting blood glucose values ​​of mice treated with low and high doses of Lactobacillus paracasei postbiotics were 7.05 mmol / L and 6.93 mmol / L, respectively. Within 2 hours, blood glucose was reduced to near the fasting level. This indicates that the Lactobacillus paracasei postbiotics of the present invention can maintain blood glucose homeostasis in high-fat mice.

[0123] Comparative Example 1

[0124] Patent CN114717146A discloses a strain of Lactobacillus paracasei, with a deposit number of GDMCC No. 62272. The effects of the strain compared with the present invention are shown in the following table:

[0125] Table 1.

[0126] As can be seen from the comparison in the above table, the Lactobacillus paracasei group of the present application lost more weight than the model group, and the dosage of the high-dose administration group of the present application was less than the dosage of the high-dose group in patent CN114717146A (hereinafter referred to as Comparative Example 1), but the fasting blood glucose of the present application was lower; for TC content, compared with the model group, the TC of the low-dose group of the present application decreased by 27.91%, and decreased by 24.68% in Comparative Example 1, and the degree of TC decrease of the 600 mg / kg dosage of the present application was the same as that of the 800 mg / kg dosage of Comparative Example 1; HDL-C increased in the present application compared with the model group, and decreased in Comparative Example 1. It is well known to those skilled in the art that increased HDL-C helps to alleviate obesity. The above results illustrate that the Lactobacillus paracasei of the present application is better in alleviating obesity than the Lactobacillus paracasei with a deposit number of GDMCC No.62272.

[0127] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A strain of Lactobacillus paracasei YJS05199, with the scientific name Lacticaseibacillus paracasei, the preservation number GDMCC No.63668, was deposited in Guangdong Provincial Microbiological Culture Collection Center on July 19, 2023.

2. A postbiotic prepared using the Lactobacillus paracasei of claim 1.

3. The method for preparing the postbiotics according to claim 2, characterized in that: The preparation method comprises the following steps: inoculating Lactobacillus paracasei into a fermentation medium for cultivation to obtain bacterial liquid, and performing heat treatment to obtain postbiotics.

4. The preparation method according to claim 3, characterized in that: The inoculation amount of the Lactobacillus paracasei is 1-5%.

5. The preparation method according to claim 3, characterized in that: The culture temperature is 35-37°C, and the culture time is 16-24h.

6. The preparation method according to claim 3, characterized in that: The heat treatment condition is pasteurization; the pasteurization temperature is 62-65° C., and the pasteurization time is 20-30 minutes.

7. Use of the Lactobacillus paracasei described in claim 1, the postbiotic described in claim 2, or the postbiotic prepared by the preparation method described in any one of claims 3 to 6 in preparing a medicament for preventing, treating or assisting in treating obesity and diseases related thereto.

8. The use according to claim 7, characterized in that: The obesity-related diseases include obesity, diabetes, hypertension, hyperlipidemia, endocrine disorders, obese cardiomyopathy, fatty liver and arteriosclerosis.

9. The use according to claim 8, characterized in that: The obesity-related disease is diabetes.

10. The use according to claim 7, characterized in that: The drug contains 2×10 5 -2×10 14 CFU / mL or 2×10 5 -2×10 14 CFU / g of Lactobacillus paracasei; the dosage of the postbiotics in the medicine is not less than 200 mg / kg body weight.

11. Use of the Lactobacillus paracasei described in claim 1, the postbiotic described in claim 2, or the postbiotic prepared by the preparation method according to any one of claims 3 to 6 in preparing foods, health products or dietary supplements for preventing or assisting in the treatment of obesity and related diseases.

12. Use of the Lactobacillus paracasei YJS05199 described in claim 1 or the postbiotic described in claim 2 or the postbiotic prepared by the preparation method described in any one of claims 3 to 6 in the preparation of antibacterial products.

13. The use according to claim 12, characterized in that: The antibacterial agent is to inhibit foodborne pathogens; the foodborne pathogens are one or more of Salmonella, Staphylococcus aureus, Escherichia coli, Vibrio parahaemolyticus, Enterobacter sakazakii, Listeria monocytogenes and Shigella.

14. The use according to claim 13, characterized in that The food-borne pathogens are Salmonella typhimurium, Staphylococcus aureus and Escherichia coli.

15. A drug for preventing, treating or assisting in treating obesity and obesity-related diseases, characterized in that: The medicine comprises the Lactobacillus paracasei described in claim 1 or the postbiotics described in claim 2 or the postbiotics prepared by the preparation method according to any one of claims 3-6.

16. A food, health product or dietary supplement for preventing or assisting in the treatment of obesity and related diseases, characterized in that: The food, health product or dietary supplement comprises the Lactobacillus paracasei described in claim 1 or the postbiotics described in claim 2 or the postbiotics prepared by the preparation method according to any one of claims 3-6.

17. An antibacterial product, characterized in that: The product comprises the Lactobacillus paracasei described in claim 1 or the postbiotics described in claim 2 or the postbiotics prepared by the preparation method according to any one of claims 3-6.

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