A strain of Lactobacillus paracasei FB97 and its application in preparing products for preventing or improving dentin sensitivity

Abstract

The present invention relates to a strain of Lactobacillus paracasei FB97, wherein the strain is classified as Lactobacillus paracasei Lacticaseibacillus paracasei , the deposit number is CGMCC No.30464. The strain can significantly inhibit oral pathogens, reduce the impact on the proliferation of beneficial oral bacteria, and prevent and improve dentin sensitivity. Therefore, the FB97 strain of Lactobacillus paracasei can be used to prepare products that prevent or improve dentin sensitivity. As a probiotic, the FB97 strain is highly safe and not prone to resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of oral care products and relates to a strain of Lactobacillus paracasei FB97 and application thereof in preparing a product for preventing or improving dentin sensitivity. Background Art

[0002] Dentin hypersensitivity is a common oral problem. It refers to the short-term, sharp pain or discomfort that occurs when the teeth are stimulated within the physiological range of mechanical, thermal, chemical, etc., and disappears quickly when the stimulation is removed. Dentin hypersensitivity occurs mainly due to the loss of enamel and cementum covering the surface of dentin, resulting in the opening of dentinal tubules on the oral and pulp sides. Any cold, hot, sour, sweet, and mechanical stimulation can cause the flow of fluid in the dentinal tubules, thereby stimulating the nerves and causing pain.

[0003] Currently, patients with dentin hypersensitivity are mainly treated with desensitizing drugs, laser treatment or filling and restoration. Desensitizing drugs such as strontium chloride can only relieve symptoms but cannot cure dentin hypersensitivity. Laser treatment requires professional equipment and well-trained doctors to operate. The instrument is large, the treatment course is long, and it is inconvenient to use. Tooth filling requires the removal of part of the tooth surface, which may cause damage to the tooth. Therefore, a new prevention and treatment plan is needed to prevent and improve dentin hypersensitivity.

[0004] Probiotics can grow and reproduce in the mouth, help maintain oral health, inhibit the growth of harmful bacteria, reduce the number of bacteria in the mouth, reduce the acidic environment in the mouth, reduce the demineralization of the tooth surface, effectively prevent or improve the corrosion of tooth enamel, and thus reduce the occurrence of tooth sensitivity. Therefore, it is very meaningful to develop an oral care product containing functional probiotics to prevent or improve dentin sensitivity. Summary of the invention

[0005] In view of the deficiencies of the prior art, the object of the present invention is to provide a strain of Lactobacillus paracasei FB97 and its application in preparing a product for preventing or improving dentin sensitivity.

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

[0007] In a first aspect, the present invention provides a strain of Lactobacillus paracasei FB97, wherein the strain is classified as Lactobacillus paracasei Lacticaseibacillus paracasei , deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.30464 and the deposit date April 28, 2024.

[0008] The present invention separates and preserves a new Lactobacillus paracasei strain capable of preventing or improving dentin sensitivity from farmhouse mare's milk in Hulunbuir City, Inner Mongolia Autonomous Region, China, and names it as Lactobacillus paracasei FB97 strain. The strain can significantly inhibit oral pathogens, reduce the effect on the proliferation of oral beneficial bacteria, and prevent and improve dentin sensitivity. Therefore, the Lactobacillus paracasei FB97 strain can be used to prepare products for preventing or improving dentin sensitivity. As a probiotic, the FB97 strain has high safety and is not easy to produce resistance.

[0009] In a second aspect, the present invention provides use of Lactobacillus paracasei FB97 or a culture thereof as described in the first aspect in preparing a product for preventing or improving dentin sensitivity.

[0010] The method for preparing the culture comprises: inoculating the Lactobacillus paracasei FB97 strain described in the first aspect into a culture medium and culturing the culture medium at 35-40° C. (e.g., 35° C., 36° C., 37° C., 38° C., 39° C., 40° C., etc.) for 24-72 h (e.g., 24 h, 30 h, 32 h, 36 h, 40 h, 48 h, 54 h, 60 h, 72 h, etc.).

[0011] Other specific point values ​​within the above numerical range can be selected and will not be described in detail here.

[0012] In a third aspect, the present invention provides a probiotic composition for preventing or improving dentin sensitivity, the probiotic composition comprising an inactivated probiotic strain, potassium nitrate, strontium chloride and tricalcium phosphate; the inactivated probiotic strain comprises the inactivated Lactobacillus paracasei FB97 described in the first aspect.

[0013] The probiotic composition involved in the present invention creatively combines the above-mentioned Lactobacillus paracasei FB97 strain with potassium nitrate, strontium chloride and tricalcium phosphate, wherein the probiotic strain mainly plays the role of regulating oral microecology, inhibiting the growth of harmful bacteria, reducing the acidic environment in the oral cavity, reducing the demineralization of the tooth surface, and effectively preventing the corrosion of tooth enamel; wherein the strontium ions in the strontium chloride can penetrate into the dentinal tubules and form a coagulant with proteins, blocking the dentinal tubules, thereby reducing the flow of liquid in the dentinal tubules caused by cold, hot, sour, sweet, and mechanical stimulation, thereby stimulating nerves to produce pain; wherein potassium nitrate mainly plays the role of reducing nerve sensitivity; tricalcium phosphate can form hydroxyapatite on the tooth surface after hydrolysis to repair tooth enamel. The various components in the probiotic composition cooperate with each other and promote each other, and the comprehensive effect makes it have an excellent effect of preventing or improving dentin sensitivity.

[0014] Preferably, the mass ratio of potassium nitrate, strontium chloride and tricalcium phosphate is (10-30):(2-5):(1-2), wherein the specific point value in (10-30) can be selected from 10, 12, 15, 18, 20, 22, 25, 28, 30, etc.; the specific point value in (2-5) can be selected from 2, 3, 4, 5, etc.; the specific point value in (1-2) can be selected from 1, 1.2, 1.5, 1.8, 2, etc.; other specific point values ​​within the above numerical range can be selected, and they will not be repeated here.

[0015] The concentration of the inactivated probiotic strain in the probiotic composition is not less than 1×10 11 Pieces / g, for example 1×10 11 pcs / g, 5×10 11 pcs / g, 1×10 12 pcs / g, 5×10 12 pcs / g, 1×10 13 pcs / g, 5×10 13 pcs / g, 1×10 14 Other specific point values ​​within this numerical range can be selected and will not be described in detail here.

[0016] Further preferably, the inactivated probiotic strain also includes inactivated Lactobacillus salivarius LS97; the classification name of the Lactobacillus salivarius LS97 is Lactobacillus salivarius Lactobacillus salivarius , deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.16922 and the deposit date of December 10, 2018.

[0017] The Lactobacillus paracasei FB97 involved in the present invention can be used in related products alone, or in combination with other strains.

[0018] The present invention also creatively discovered that the above-mentioned Lactobacillus paracasei FB97 strain can be used in combination with Lactobacillus salivarius LS97 strain to prevent or improve dentin sensitivity, and has a significantly better effect than a single strain or other strain combinations, indicating that the FB97 strain and the LS97 strain have a synergistic effect in the above-mentioned efficacy.

[0019] Preferably, the ratio of the bacterial counts of Lactobacillus salivarius LS97 to Lactobacillus paracasei FB97 is 1:10-10:1, for example, 1:10, 1:9, 1:8, 1:7, 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, etc. Other specific point values ​​within this numerical range can be selected, and they will not be described one by one here.

[0020] Based on the potential interaction between the FB97 strain and the LS97 strain in the above-mentioned efficacy, the two strains have a better synergistic effect when the above-mentioned specific bacterial number ratio relationship is met.

[0021] In a fourth aspect, the present invention provides the use of the Lactobacillus paracasei FB97 described in the first aspect or the probiotic composition described in the third aspect in the preparation of oral care products; the oral care products include toothpaste, mouthwash, oral lozenges, and oral gels.

[0022] In a fifth aspect, the present invention provides a toothpaste for preventing or improving dentin sensitivity, wherein the raw materials for preparing the toothpaste include: the probiotic composition described in the third aspect, a moisturizer, an abrasive, a foaming agent, a thickener, and a taste regulator.

[0023] Wherein the humectant can be selected from any one or a combination of at least two of glycerol, sorbitol, xylitol or polyethylene glycol. Wherein the friction agent can be selected from any one or a combination of at least two of calcium carbonate, calcium hydrogen phosphate, silicon dioxide or aluminum hydroxide. Wherein the foaming agent can be selected from any one or a combination of at least two of sodium lauryl sulfate, sodium lauryl sulfate or 2-acyloxy bond sodium sulfonate. Wherein the thickener can be selected from any one or a combination of at least two of carboxymethyl cellulose, hydroxyethyl cellulose, carbo resin, xanthan gum, modified guar gum or carrageenan.

[0024] Preferably, the mass percentage of the probiotic composition in the toothpaste is 0.1-5%, for example 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, etc. Other specific point values ​​within this numerical range can be selected and will not be described one by one here.

[0025] In a sixth aspect, the present invention provides a method for preparing the toothpaste for preventing or improving dentin sensitivity according to the fifth aspect, the preparation method comprising: mixing the various preparation raw materials, and homogenizing them with a homogenizer to obtain.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention separates and preserves a new Lactobacillus paracasei strain capable of preventing or improving dentin sensitivity from farmhouse mare's milk in Hulunbuir City, Inner Mongolia Autonomous Region, China, and names it as Lactobacillus paracasei FB97 strain. The strain can significantly inhibit oral pathogens, reduce the effect on the proliferation of oral beneficial bacteria, and prevent and improve dentin sensitivity. Therefore, the Lactobacillus paracasei FB97 strain can be used to prepare products for preventing or improving dentin sensitivity. As a probiotic, the FB97 strain has high safety and is not easy to produce resistance.

[0028] Further, the present invention creatively combines the above-mentioned Lactobacillus paracasei FB97 strain with potassium nitrate, strontium chloride and tricalcium phosphate, wherein the probiotic strain mainly plays the role of regulating oral microecology, inhibiting the growth of harmful bacteria, reducing the acidic environment in the oral cavity, reducing the demineralization of the tooth surface, and effectively preventing the corrosion of tooth enamel; wherein the strontium ions in the strontium chloride can penetrate into the dentinal tubules and form a coagulant with protein, blocking the dentinal tubules, thereby reducing the flow of liquid in the dentinal tubules caused by cold, hot, sour, sweet, and mechanical stimulation, thereby stimulating the nerves to produce pain; wherein potassium nitrate mainly plays the role of reducing nerve sensitivity; tricalcium phosphate can form hydroxyapatite on the tooth surface after hydrolysis to repair tooth enamel. The various components in the probiotic composition cooperate with each other and promote each other, and the comprehensive effect makes it have an excellent effect of preventing or improving dentin sensitivity.

[0029] The FB97 strain involved in the present invention is classified and named as Lactobacillus paracasei Lacticaseibacillus paracasei The depository is the General Microbiology Center of China Microbiological Culture Collection Administration. The deposit date is April 28, 2024. The deposit number is CGMCC No.30464. The address is: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing.

[0030] The LS97 strain involved in the present invention is classified and named as Lactobacillus salivarius Lactobacillus salivarius The depository is the General Microbiology Center of China Microbiological Culture Collection Administration. The deposit date is December 10, 2018. The deposit number is CGMCC No.16922. The address is: No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing. DETAILED DESCRIPTION

[0031] In order to further explain the technical means and effects adopted by the present invention, the technical solution of the present invention is further described below in conjunction with the preferred embodiments of the present invention, but the present invention is not limited to the scope of the embodiments.

[0032] The components of the BHI medium involved below are: 4.0 g / L of bovine brain extract powder, 4.0 g / L of bovine heart extract powder, 5.0 g / L of peptone, 16.0 g / L of casein peptone, 5.0 g / L of sodium chloride, 2.0 g / L of glucose, 2.5 g / L of disodium hydrogen phosphate dodecahydrate, and pH value is 7.2~7.4.

[0033] The components of the MRS medium involved below are: yeast powder 5.0 g / L, beef extract 10.0 g / L, peptone 10.0 g / L, glucose 20.0 g / L, anhydrous sodium acetate 2.0 g / L, diammonium hydrogen citrate 2.0 g / L, dipotassium hydrogen phosphate trihydrate 2.6 g / L, manganese sulfate monohydrate 0.25 g / L, magnesium sulfate heptahydrate 0.5 g / L and Tween-80 1 mL / L, pH 6.2~6.4.

[0034] The potassium nitrate mentioned below is the product purchased from Sinopharm Chemical Reagent Co., Ltd. with model number 10017218, the strontium chloride is the product purchased from Sinopharm Chemical Reagent Co., Ltd. with model number 20042916, and the tricalcium phosphate is the product purchased from Sinopharm Chemical Reagent Co., Ltd. with model number XW775887401.

[0035] The FB97 strain referred to below is named as Lactobacillus paracasei Lacticaseibacillus paracasei The deposit date is April 28, 2024, and the deposit number is CGMCC No.30464.

[0036] The LS97 strains referred to below are designated as Lactobacillus salivarius Lactobacillus salivarius The deposit date is December 10, 2018, and the deposit number is CGMCC No.16922.

[0037] The inactivation method of the inactivated strains involved below is as follows: the desired strain is inoculated into MRS medium at a concentration of 2%, and the bacterial solution is obtained after shaking culture at 37°C for 24 hours. The pH of the bacterial solution is adjusted to 7.0 using NaOH, and the solution is centrifuged at 5000 rpm for 5 minutes, the supernatant is discarded, and the centrifuged precipitate (bacterial mud) is collected. A heat shock protective agent is added to the bacterial mud in proportion (bacterial mud: 30% trehalose solution = 1:1, W / W). The obtained mixture is preheated to 80°C, and then stirred continuously at 80°C and 200 rpm for 30 minutes to complete the inactivation, and an inactivated emulsion is obtained. The inactivated emulsion is spray-dried and crushed to obtain an inactivated bacterial powder, which is stored at room temperature and protected from light for later use. Example 1

[0038] Screening of Lactobacillus paracasei FB97:

[0039] 5 mL of the dilution solution of mare's milk wine from farmers in Hulunbuir City, Inner Mongolia Autonomous Region, China was extracted and serially diluted 10 times to 10 with 0.9% saline. -6, take 200 μL of each dilution concentration and spread it on selective MRS medium (the medium contains the antibiotic mupirocin lithium salt, which can inhibit most bacteria except bifidobacteria, purchased from Haibo Biological), culture it anaerobically at 37°C for 48 hours, and separate different single colonies on the plate. Use a sterilized inoculation loop to pick the above-mentioned different single colonies and streak them on MRS solid medium for purification, culture them anaerobically at 37°C for 48 hours, and preserve them with glycerol at a mass concentration of 30%. The following in vitro physiological properties tests were performed on the preserved single bacteria, and a single strain with the best oral epithelial cell adhesion and antibacterial ability was screened out, and a strain of Lactobacillus paracasei was obtained, named FB97. The details are as follows:

[0040] (1) Oral epithelial cell adhesion ability test:

[0041] The concentration of digested human oral epithelial cells was adjusted to 1 × 10 5 / mL, 1 mL was taken from each well and inoculated into a 12-well cell culture plate, incubated in a 5% CO2 incubator until the cells grew into a monolayer, washed twice with sterile PBS, one well was digested with trypsin, and the cells were counted with a hemocytometer; 1 mL of the selected strain suspension was added to the other wells (the concentration of the bacterial suspension was adjusted to 10 8 CFU / mL), incubated at 37℃ in a 5% CO2 incubator for 2 h, washed the cells 5 times with sterile PBS to remove the non-adherent bacterial suspension, added 0.2 mL of trypsin EDTA buffer to each well to digest the cells for 5 min, added 0.8 mL of PBS after digestion, and took the bacterial solution for dilution and live bacterial count.

[0042] (2) Antibacterial ability test:

[0043] The Oxford cup method was used to test the inhibitory ability against oral pathogens: oral pathogenic strains Streptococcus mutans and Porphyromonas gingivalis were inoculated into BHI medium, cultured overnight at 37°C and 250 rpm in a constant temperature shaker to prepare pathogen suspension. MRS solid medium was cooled to about 55°C and mixed with the pathogen suspension in a certain proportion to make the number of viable pathogens in the system reach 10 6 CFU / mL, and then quickly pour it into the plate with the Oxford cup placed in advance. After the culture medium cools and solidifies, take out the Oxford cup, inject 200 μL of the strain solution to be tested into each well, cover the plate lightly and place it in a 37℃ constant temperature incubator, observe after the appropriate incubation time, and measure the diameter of the inhibition zone with a vernier caliper. The larger the inhibition zone, the stronger the antibacterial ability. Example 2

[0044] Identification of Lactobacillus paracasei FB97:

[0045] The strains screened in Example 1 were subjected to 16S rDNA molecular biological identification in the following steps:

[0046] The strain stored at -80°C was taken out and inoculated into a centrifuge tube containing 20 mL of MRS liquid culture medium at a ratio of 2%. After culturing at 37°C for 24 h, the strain was centrifuged and centrifuged at 8000 rpm for 15 min. The supernatant was removed and the bacteria were collected. The genome of the strain was extracted, and bacterial universal primers were added for PCR amplification, and the amplified product was sequenced and identified. The strain was sequenced and analyzed, and its 16S rDNA sequence was shown in SEQ ID No: 1. The sequence obtained by sequencing was compared with the nucleic acid sequence in the DNA sequence database, and the results showed that the strain was Lactobacillus paracasei.

[0047] SEQ ID No: 1:

[0048]

[0049] Preparation Example 1

[0050] This preparation example provides a probiotic composition, which is composed of inactivated FB97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride, and tricalcium phosphate is 20:3:1, and the content of FB97 strain in the probiotic composition is 1×10 11 Pieces / g.

[0051] Preparation Example 2

[0052] This preparation example provides a probiotic composition, which is composed of inactivated FB97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride, and tricalcium phosphate is 30:5:2, and the content of FB97 strain in the probiotic composition is 1×10 11 Pieces / g.

[0053] Preparation Example 3

[0054] This preparation example provides a probiotic composition, which is composed of an inactivated FB97 strain, an inactivated LS97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride, and tricalcium phosphate is 20:3:1, and the total content of the FB97 strain and the LS97 strain in the probiotic composition is 1×10 11 / g, and the ratio of the bacterial counts of LS97 strain and FB97 strain was 1:1.

[0055] Preparation Example 4

[0056] This preparation example provides a probiotic composition, which is composed of an inactivated FB97 strain, an inactivated LS97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride, and tricalcium phosphate is 20:3:1, and the total content of the FB97 strain and the LS97 strain in the probiotic composition is 1×10 11 / g, and the ratio of the bacterial counts of LS97 strain and FB97 strain was 3:1.

[0057] Comparative Preparation Example 1

[0058] This comparative preparation example provides a probiotic composition, which is composed of inactivated LS97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride, and tricalcium phosphate is 20:3:1, and the content of LS97 strain in the probiotic composition is 1×10 11 Pieces / g.

[0059] Comparative Preparation Example 2

[0060] This comparative preparation example provides a probiotic composition, which is composed of inactivated ATCC25302 strain, inactivated LS97 strain, potassium nitrate, strontium chloride, and tricalcium phosphate, wherein the mass ratio of potassium nitrate, strontium chloride and tricalcium phosphate is 20:3:1, and the total content of FB97 strain and LS97 strain in the probiotic composition is 1×10 11 / g, and the ratio of the bacterial counts of LS97 strain and FB97 strain was 1:1.

[0061] Comparative Preparation Example 3

[0062] This comparative preparation example provides a probiotic composition, the components of which differ from those of Preparation Example 1 only in that potassium nitrate is not contained, and its mass is distributed to the mass of strontium chloride and tricalcium phosphate according to the mass ratio, and the rest remain unchanged.

[0063] Comparative Preparation Example 4

[0064] This comparative preparation example provides a probiotic composition, the components of which differ from those of Preparation Example 1 only in that strontium chloride is not contained, and its mass is distributed to the mass of potassium nitrate and tricalcium phosphate according to the mass ratio, and the rest remain unchanged.

[0065] Comparative Preparation Example 5

[0066] This comparative preparation example provides a probiotic composition, the components of which differ from those of Preparation Example 1 only in that tricalcium phosphate is not contained, and its mass is distributed to the mass of potassium nitrate and strontium chloride according to the mass ratio, and the rest remain unchanged.

[0067] Test Example 1

[0068] Antibacterial test:

[0069] (1) Preparation of test bacteria: Oral pathogenic bacteria Streptococcus mutans, Porphyromonas gingivalis, and Fusobacterium nucleatum were inoculated into BHI liquid culture medium at 2% (V / V). After culturing at 37°C for 24 h, the bacterial solution concentration was adjusted to 10 8 The beneficial oral bacteria Lactobacillus salivarius was inoculated into MRS liquid culture medium at 2% (V / V), cultured at 37°C for 24 h, and the bacterial solution concentration was adjusted to 10 8 CFU / mL.

[0070] (2) Sample preparation: The probiotic compositions prepared in Preparation Example 1-4 and Comparative Preparation Example 1-2 were diluted with PBS buffer to a concentration of 0.1%.

[0071] (3) Experimental operation: Take a sterile test tube, add 5.0 mL of sample, place it in a 20℃ water bath for 5 min, then add 0.1 mL of bacterial suspension, mix quickly and start timing immediately. After the test bacteria and sample react for 1 min, take 1.0 mL of the test bacteria and sample mixture and inoculate 2 plates respectively, and pour the culture medium. At the same time, use PBS instead of the sample to perform a parallel test as a positive control. All test samples and control samples are cultured at 36℃±1℃ and cultured for 48 h to observe the final results: the test is repeated 3 times and the inhibition rate is calculated.

[0072] Calculation of antibacterial rate:

[0073] Where: X--- Antibacterial rate, %; A 0 --- The amount of bacteria recovered in the positive control group, CFU / mL; A 1 --- The amount of bacteria recovered in the experimental group, CFU / mL.

[0074] The results are shown in Tables 1 to 4.

[0075] Table 1

[0076]

[0077] Table 2

[0078]

[0079] Table 3

[0080]

[0081] Table 4

[0082]

[0083] It can be seen from the data results in Tables 1 to 4 that the probiotics and probiotic compositions involved in the present invention can significantly inhibit oral pathogens while reducing the impact on the proliferation of oral beneficial bacteria, and the FB97 strain and the LS97 strain have a synergistic effect in the above-mentioned effects.

[0084] Test Example 2

[0085] Dentin permeability test:

[0086] (1) Preparation of dentin slices: Intact and non-excessively worn incisors were selected from the middle four lower incisors of cattle slaughtered at 3-7 years of age. After extraction, the teeth were cleaned of tartar and attached soft tissues with hand-held instruments, placed in 0.5% chloramine T solution for 1 week, and then stored in distilled water at 4°C for 1 month. Dentin slices with a thickness of (0.5±0.05) mm were cut along the long axis of the tooth as close to the pulp cavity as possible using a low-speed cutter under water cooling. Dentin slices close to the cervical part of the tooth were used for the test. All dentin slices were etched with 35% (w / w) phosphoric acid solution on both sides for 30 s to remove the smear layer, rinsed with deionized water, and then ultrasonically cleaned in deionized water for 5 min.

[0087] (2) Determination of baseline permeability value: The dentin slice was installed in a hydraulic permeability device. The permeability value of the dentin slice was measured using distilled water as the permeability liquid under a water column pressure of 20 cm. This value was the permeability value before the dentin slice was treated with the sample and was set as the baseline permeability value of the dentin slice. The average value of three measurements was recorded as Lp0.

[0088] (3) Determination of permeability value after sample use: The distal pulp surface of the dentin slice was immersed in a 0.1% solution of the probiotic composition prepared in Preparation Examples 1-4 and Comparative Preparation Examples 1-5 for 3 min. Then, the permeability value was measured according to the baseline permeability value determination method. This value is the permeability value of the dentin slice after the sample was treated.

[0089] Relative permeability = (Lp1 / Lp0) × 100%

[0090] Where Lp1 --- The permeability value of the dentin slice after sample treatment is expressed in microliters per minute per square centimeter per centimeter of water column (μL·min -1 cm -2 cmH2O -1 ); Lp0 is the baseline permeability value of the dentin slice, in microliters per minute per square centimeter per centimeter of water column (μL·min -1 cm -2 cmH2O -1 The results were expressed as the average relative permeability value and standard deviation of 5 dentin slices, as shown in Table 5.

[0091] Table 5

[0092]

[0093] It can be seen from the data results in Table 5 that the probiotics and probiotic compositions involved in the present invention can significantly reduce dentin permeability and reduce dentin sensitivity, among which tricalcium phosphate plays a major contribution, and the strain formula also affects the above effects. The FB97 strain and the LS97 strain have a synergistic effect on the above effects.

[0094] Application Example 1

[0095] This application example provides a toothpaste product, wherein the raw materials for preparation are composed of the following by mass percentage: 0.1% of the probiotic composition prepared in Preparation Example 1, 40% of calcium hydrogen phosphate dihydrate, 20% of glycerol, 13% of sorbitol, 1.5% of sodium lauryl sulfate, 1% of flavor, 0.8% of sodium pyrophosphate, 0.2% of sodium saccharin, 0.1% of sodium carboxymethyl cellulose, and the balance is water. The preparation method is as follows: after mixing the raw materials for preparation, homogenizing them with a homogenizer to obtain the toothpaste product.

[0096] Application Example 2-4

[0097] This application example provides three toothpaste products, and the difference in the preparation raw materials between them and application example 1 is that the probiotic composition prepared in preparation example 1 is replaced by the probiotic compositions prepared in preparation examples 2-4 in equal amounts, and other conditions remain unchanged.

[0098] Comparative Application Examples 1-5

[0099] This comparative application example provides five toothpaste products, the preparation raw materials of which differ from those of Application Example 1 only in that equal amounts of the probiotic composition prepared in Preparation Example 1 are replaced by probiotic compositions prepared in Comparative Preparation Examples 1-5, respectively, and other conditions remain unchanged.

[0100] Comparative Application Example 6

[0101] This comparative application example provides a toothpaste product, the raw materials of which differ from those of application example 1 only in that the probiotic composition prepared in preparation example 1 is missing, and its content is supplemented by glycerol. Other conditions remain unchanged.

[0102] Test Example 3

[0103] Clinical trials:

[0104] 200 patients were randomly divided into 10 groups, with 20 patients in each group. Groups 1-9 used the toothpastes prepared in application examples 1-4 and comparative application examples 1-5, respectively, and group 10 was the control group, using the toothpaste prepared in comparative application example 6, which was used once a day in the morning and evening. The dentin hypersensitivity of the 10 groups of patients was compared before treatment, 2 weeks, 4 weeks, and 8 weeks after treatment. The evaluation index was the Schiff sensitivity index and VAS pain index of each group of patients as the evaluation criteria; at the same time, the adverse reactions in each group were investigated. The results are shown in Table 6.

[0105] Table 6

[0106]

[0107] It can be seen from the data results in Table 6 that: compared with the comparative application examples, the probiotic composition involved in the present invention and the toothpaste product prepared therefrom, by combining the probiotic strains with potassium nitrate, strontium chloride and tricalcium phosphate, the various components cooperate and promote each other, so that it has excellent effects in preventing and improving dentin sensitivity, and the effect is better when the probiotic strains are selected from the FB97 strain and the LS97 strain.

[0108] The applicant declares that the present invention illustrates the technical solution of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0109] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0110] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

Claims

1. A probiotic composition for preventing or improving dentin sensitivity, It is characterized in that The probiotic composition comprises an inactivated probiotic strain, potassium nitrate, strontium chloride and tricalcium phosphate; the inactivated probiotic strain comprises inactivated Lactobacillus paracasei FB97 and inactivated Lactobacillus salivarius LS97; The classification of the Lactobacillus paracasei FB97 is named as Lactobacillus paracasei ( Lacticaseibacillus paracasei ), deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.30464 and the deposit date April 28, 2024; The classification of the Lactobacillus salivarius LS97 is named Lactobacillus salivarius ( Lactobacillus salivarius ), deposited in the General Microbiology Center of China Microorganism Culture Collection Administration, with the deposit number CGMCC No.16922 and the deposit date being December 10, 2018.

2. The probiotic composition according to claim 1, It is characterized in that The mass ratio of potassium nitrate, strontium chloride and tricalcium phosphate is (10-30):(2-5):(1-2); The concentration of the inactivated probiotic strain in the probiotic composition is not less than 1×10 11 Pieces / g.

3. The probiotic composition according to claim 1, It is characterized in that The bacterial count ratio of the Lactobacillus salivarius LS97 to the Lactobacillus paracasei FB97 is 1:10-10:

1.

4. Use of the probiotic composition according to any one of claims 1 to 3 in the preparation of oral care products; the oral care products include toothpaste, mouthwash, oral lozenges, and oral gels.

5. A toothpaste for preventing or improving dentin sensitivity. It is characterized in that The raw materials for preparing the toothpaste include: the probiotic composition according to any one of claims 1 to 3, a moisturizer, an abrasive, a foaming agent, a thickener, and a taste regulator.

6. The toothpaste for preventing or improving dentin hypersensitivity according to claim 5, It is characterized in that The mass percentage of the probiotic composition in the toothpaste is 0.1-5%.

7. The method for preparing a toothpaste for preventing or improving dentin hypersensitivity according to claim 5, It is characterized in that The preparation method comprises: mixing various preparation raw materials, and then homogenizing them with a homogenizer to obtain the product.

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