Lactobacillus paracasei LPc-HF46 for improving memory and concentration and promoting children to grow tall as well as postbiotic microbial inoculum, preparation method and application of lactobacillus paracasei LPc-HF46 and postbiotic microbial inoculum

Abstract

The invention discloses a lactobacillus paracasei LPc-HF46 capable of improving memory and concentration and promoting children to grow tall, a preparation method and application of the lactobacillus paracasei LPc-HF46. The strain is preserved in the China Center for Type Culture Collection (CCTCC), the preservation number is CCTCC NO: M 20241569, the strain is classified and named as lactobacillus paracasei LPc-HF46, and the preservation date is July 15, 2024. The lactobacillus paracasei LPc-HF46 is named as lactobacillus paracasei LPc-HF46. The lactobacillus paracasei LPc-HF46 is named as lactobacillus paracasei LPc-HF46. No matter whether the strain LPc-HF46 is in a viable or inactivated state, the strain LPc-HF46 has the effects of improving the memory and concentration of children and promoting the growth of the children.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of Lactobacillus casei, and mainly relates to a Lactobacillus paracasei LPc-HF46 for improving memory and concentration and promoting the growth of children, a postbiotic agent, a preparation method and application. BACKGROUND

[0002] The importance of children's memory and concentration is self-evident. They are indispensable abilities in children's learning and life, and have a profound impact on the growth and development of children. Concentration is the foundation of learning, which not only affects the learning performance of children, but also relates to the development of children's thinking ability, creativity, work efficiency and productivity. Children with strong concentration can better absorb information, understand concepts and remember knowledge, thereby performing better in learning. In addition, concentration helps to cultivate children's self-control, patience, social skills and emotional management skills. Memory is a repository of knowledge and experience, which has a direct impact on children's cognitive development, problem-solving ability and creativity. A child with strong memory can better remember important information and details, which is crucial for their learning and daily life. However, many children currently have difficulty maintaining attention, are easily distracted, have no beginning and no end, and have a chaotic daily life, etc. 2-8 years old is a critical period for the development of children's brains and bodies. At this time, improving children's memory, concentration or logical thinking ability can be more effective. Therefore, most parents should pay attention to the cultivation of children's concentration and the improvement of memory during childhood.

[0003] The present application aims to provide a Lactobacillus paracasei LPc-HF46 for improving memory and concentration and promoting the growth of children. SUMMARY

[0004] Therefore, the present application aims to provide a Lactobacillus paracasei LPc-HF46 for improving memory and concentration and promoting the growth of children, so as to open its actual application scenarios and fields.

[0005] In a first aspect, the present application screens a Lactobacillus paracasei, which is preserved in the China Center for Type Culture Collection, has a preservation number of CCTCC NO: M 20241569, is classified and named as Lactobacillus paracasei LPc-HF46, and is preserved on July 15, 2024.

[0006] In a second aspect, the present application discloses application of the Lactobacillus paracasei LPc-HF46 in preparation of a product for improving memory and concentration.

[0007] In a third aspect, the application discloses the application of the Lactobacillus paracasei LPc-HF46 in the preparation of a product for promoting the growth of children.

[0008] In a fourth aspect, the application discloses a preparation method of the Lactobacillus plantarum powder with the functions of lubricating intestines, defecating and improving immunity.

[0009] S1, preparing a seed suspension, 1 mL of glycerol tube of Lactobacillus paracasei LPc-HF46 preserved at-20 DEG C is inoculated into 40-110 mL of MRS liquid medium, and then the seed suspension is cultured at 31-37 DEG C for 12-16 hours, and then the seed suspension is washed with sterile water for 3 times, and then the seed suspension is adjusted to a proper concentration (10 6 -10 7 CFU / ml) for standby;

[0010] S2, obtaining a fermentation liquid, the seed suspension is transferred into the fermentation liquid, and then the fermentation liquid is aerated and fermented under the conditions of 31-37 DEG C and 100-130 rpm, and then the fermentation is performed for 36-72 hours;

[0011] S3, centrifugal collection, 20-30 ml of the fermentation liquid after the fermentation is completed is placed in a sterile 50 ml centrifugal tube for centrifugal collection, and then the supernatant is collected;

[0012] S4, preparation of the freeze-dried bacterial suspension, the centrifuged bacterial body is collected, and then a bacterial mud protective agent prepared from milk powder 21%, trehalose 15%, glycerol 2%, xylo-oligosaccharide 5% and ultrapure water is added and stirred, so that the freeze-dried bacterial suspension is obtained, and then the freeze-dried bacterial suspension is placed at room temperature for 1 hour, so that the protective agent and the bacterial body are fully fused;

[0013] S5, vacuum freeze-drying, the bacterial body is pre-frozen in a-80 DEG C refrigerator for 2 hours, and then the bacterial body is immediately placed in a freeze-drying machine to avoid damage of the bacterial body caused by sudden temperature rise. The sample is continuously freeze-dried in the freeze-drying machine for 24 hours, so that the Lactobacillus paracasei LPc-HF46 powder is obtained, wherein the content of the Lactobacillus paracasei LPc-HF46 strain is 10 10 -10 12 CFU / g, and the freeze-drying machine is started in advance, so that the freezing temperature is reduced to-55 DEG C, and the vacuum degree is reduced to 1000 Pa when the freeze-drying machine works.

[0014] In the embodiment of the present application, the MRS liquid medium in step S1 is specifically: 10 g / L of proteose peptone, 10 g / L of beef extract, 5 g / L of yeast powder, 2 g / L of potassium phosphate dibasic, 2 g / L of citric acid, 5 g / L of sodium acetate, 1 mL / L of Tween-80, 0.2 g / L of magnesium sulfate, 0.05 g / L of sulfuric acid, 20 g / L of glucose, pH = 6.5, sterilized at 121°C for 20 min. In the embodiment of the present application, the ratio of the amount of air to the tank volume in step S2 is 1:0.5-1 (v / v.m).

[0015] In the embodiment of the present application, the centrifugal condition in step S3 is 4000 r / min, 20 min, 4°C or 6000 r / min, 10 min, 4°C.

[0016] In the embodiment of the present application, the volume of the protective agent added in step S4 is 1 / 5 of the culture solution before centrifugation.

[0017] In the embodiment of the present application, a food or a medicine containing the Lactobacillus paracasei LPc-HF46 is also provided.

[0018] In the embodiment of the present application, a postbiotic product containing the Lactobacillus paracasei LPc-HF46 is also provided.

[0019] The beneficial effects of the present application are:

[0020] (1) The strain LPc-HF46 of the present application can effectively improve the memory and concentration of children whether in a live state or in an inactivated state.

[0021] (2) The Lactobacillus plantarum of the present application also has the function of significantly promoting the growth of children.

[0022] (3) The strain of the present application is effective in an inactivated state, can significantly broaden the application scenarios of the strain, has great technical progress, and can be made into a postbiotic product. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0024] Figure 1 It is an optical microscope photo of the Lactobacillus paracasei LPc-HF46.

[0025] Figure 2 It is a graph of the determination of the number of times of autonomous activity of mice.

[0026] Figure 3 Mouse femur length chart. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects of the present application patent more clear, the present application patent is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application content, and are not used to limit the present application patent.

[0028] Example 1 Sublactobacillus paracasei LPc-HF46 screening source description

[0029] The applicant has carried out a large number of screening from cheese, and several strains of sublactobacillus paracasei with good health care function have been screened, wherein the present application involves sublactobacillus paracasei LPc-HF46.

[0030] With reference to the existing technology, the identification of strain LPc-HF46

[0031] Morphological identification

[0032] Sublactobacillus paracasei LPc-HF46 is a gram-positive bacterium, and the bacterial body is rod-shaped (0.8-1.0 x 2.0-4.0 μm), square at both ends, single or chain arrangement, no flagellum, not moving, like Figure 1 As shown in the figure. Facultative anaerobic, growth temperature range 10-40℃, the optimum growth temperature is 37℃.

[0033] Physiological and biochemical identification

[0034] According to the "Berger's Bacterium Identification Manual" and "Common Bacterium System Identification Manual", the physiological and biochemical corresponding indexes of the strain LPc-HF46 are determined, and the specific results are shown in Table 1, and it can be known from the reference strain identification manual that the strain LPc-HF46 meets the characteristics of lactobacillus genus bacteria, and it can be preliminarily determined that it is sublactobacillus paracasei.

[0035] Table 1 physiological and biochemical characteristics identification results of strain LPc-HF46

[0036]

[0037]

[0038] Molecular biology identification

[0039] The 16S DNA sequence of the strain LPc-HF46 genome was amplified by PCR using bacterial universal primers, and the PCR product was verified by agarose electrophoresis. The PCR amplification product was sent to Shanghai Shenguo for sequence determination. The sequencing results of the PCR product were compared with the 16S rDNA sequence in Genback. The sequence alignment showed that the sequence of LPc-HF46 had 99% homology with Lactobacillus paracasei PC-01. In combination with morphological characteristics and physiological and biochemical characteristics, it was determined that the strain LPc-HF46 was Lactobacillus paracasei. The strain LPc-HF46 was named Lactobacillus paracasei LPc-HF46, and was preserved in the China Center for Type Culture Collection, with the preservation number CCTCC NO: M 20241569.

[0040] Example 2 Preparation of bacterial powder

[0041] S1, preparation of seed suspension, 1 mL of glycerol tube of Lactobacillus paracasei LPc-HF46 preserved at -20℃ was inoculated into 70 mL of MRS liquid medium containing peptone 10 g / L, beef extract 10 g / L, yeast powder 5 g / L, potassium phosphate dibasic 2 g / L, citric acid tri 2 g / L, sodium acetate 5 g / L, Tween-80 1 mL / L, magnesium sulfate 0.2 g / L, sulfuric acid 0.05 g / L, glucose 20 g / L, pH = 6.5, sterilized at 121℃ for 20 min, and incubated at 37℃ for 16 h. The bacterial suspension was washed with sterile water for 3 times, and the concentration was adjusted to 10 7 CFU / ml with sterile water for standby;

[0042] S2, obtain fermentation broth, the seed suspension was transferred to the fermentation broth (skim milk powder (50 g / L), soybean protein isolate (8 g / L), glucose (20 g / L), beef extract (8 g / L), NaCl (23 g / L), MgSO4·7H2O (2 g / L), Span S-80 (1 g / L), pH adjusted to 5.80, sterilized at 121℃ for 20 min), and fermented under the conditions of 37℃, 120 rpm stirring and aeration, with the ratio of air volume to tank volume being 1:0.5 (v / v.m), for 48 h to obtain the fermentation broth;

[0043] S3, centrifugal collection, 30 ml of fermentation broth after fermentation was collected and placed in a sterile 50 ml centrifuge tube for centrifugation at 4000 r / min, 4℃ for 20 min. The supernatant was discarded, and the bacterial slurry was collected;

[0044] S4, preparation of the freeze-dried bacterial suspension, centrifugal the bacterial body, add the bacterial mud protective agent prepared by 21% milk powder, 15% trehalose, 2% glycerol, 5% xylo-oligosaccharide and ultrapure water, vortex mix, the volume of the protective agent added is 1 / 5 of the culture solution before centrifugation, obtain the freeze-dried bacterial suspension, place at room temperature for 1 h, so that the protective agent and the bacterial body are fully fused;

[0045] S5, vacuum freeze-drying, pre-freeze in a -80℃ refrigerator for 2 h, immediately put into a freeze-drying machine after taking out, to avoid damage to the bacterial body due to sudden temperature rise. Place the sample in the freeze-drying machine for continuous freeze-drying for 24 h to obtain Lactobacillus paracasei LPc-HF46 bacterial powder, wherein the content of Lactobacillus paracasei LPc-HF46 strain is 10 12 CFU / g, (the freeze-drying machine is to be started in advance, and the cold trap temperature is reduced to -55℃, and the vacuum degree is reduced to 1000 Pa when working).

[0046] Preparation of inactivated bacterial powder: except that the bacterial mud obtained in the above step S3 is treated at 121℃ for 30 min to obtain inactivated bacteria, the remaining steps are the same as above.

[0047] The bacterial powder can be further processed to prepare food, medicine and postbiotic products.

[0048] Comparative Example 1: To this end, the present application also provides a Lactobacillus paracasei PC-01 as Comparative Example 1. The steps are the same as those of Example 1 above, the only difference is that the strain used for fermentation is Lactobacillus paracasei PC-01, and through the above steps, Lactobacillus paracasei PC-01 bacterial powder is also obtained. Lactobacillus paracasei PC-01 is extracted from a live bacterial type lactic acid bacteria beverage (live bacteria number is about 5×10 10 CFU / g, 100 g / bottle), provided by Mengniu Group.

[0049] Experiment 1 Application of Lactobacillus paracasei LPc-HF46 in improving memory

[0050] Animal experiments:

[0051] In this experiment, SPF healthy Kunming mice of 5 weeks old and uniform weight were selected, 50 male mice with an initial weight of 22±2.7 g were purchased from Beijing HFK Bioscience Co., Ltd. In order to adapt the mice to the surrounding environment, the 50 mice were adaptively fed for one week, and the feeding conditions were: humidity 4%, constant temperature 24±2℃, black night / white day cycle, free drinking water and food.

[0052] Experimental grouping and model construction:

[0053] 50 mice were randomly divided into 5 groups, namely normal group, model group, live bacteria Example 2 group, Comparative Example 1 group and inactivated Example 2 group, 10 mice in each group, and the mice were marked by ear cutting.

[0054] Except that the normal group was free to eat the basic feed and water without any intervention, and the mice were observed daily, the body weight was measured every week, and the feces were collected, the rest of the four groups were free to eat the basic feed and water, and then 40% alcohol 10 ml / kg was gavaged, and the gavage was continued for 28 days. The body weight was measured every day, and the fecal samples were collected. Among them, in addition to the daily ration of the model group being the basic feed, the live bacteria Example 2 group: 1% of the live bacteria state of Lactobacillus paracasei LPc-HF46 was added to the feed. Comparative Example 1 group: 1% of the live bacteria state of Lactobacillus paracasei PC-01 powder was added to the feed. Inactivated Example 2 group: 1% of the inactivated state of Lactobacillus paracasei LPc-HF46 powder was added to the feed.

[0055] Automatic recording of water maze experiment

[0056] The water maze experiment started after 28 days of gavage, and the mice were continuously gavaged during the experiment. The experiment was performed for 6 days, and the first 5 days were the positioning navigation experiment, and the 6th day was the spatial test experiment. Positioning navigation experiment method: train 3 times a day, each time the mouse is put into the water from the entrance of the maze, and at the same time the timing starts and a bright green stick is used to guide the mouse to find the exit of the maze. Record the time required for the mouse to find the exit of the maze from the water, i.e. escape latency. If the mouse fails to find the exit within 5 minutes, it will be guided to the shore and allowed to rest on the shore for 2 minutes, at which time the escape latency is recorded as unqualified. Spatial test experiment method: on the 6th day, the guide was removed, and the mouse was put into the water from the entrance of the maze, and the mouse was allowed to find the exit in the maze, and the time required for the mouse to reach the exit was recorded.

[0057] According to the results in Table 1, the data from the model group shows that the mouse was successfully modeled after alcohol gavage, and the data from the comparative example group shows that the use of Lactobacillus paracasei PC-01 powder has little effect on the treatment of memory loss mice, however, after the treatment of Lactobacillus paracasei LPc-HF46 live bacteria or inactivated bacteria powder, the memory of the mice was significantly restored, and it is worth noting that the memory of the live bacteria group is better than that of the normal group.

[0058] Table 1

[0059] Group Time to reach the platform during the test period / s Normal group 20±5 Model Group 65±7 Live bacteria example 2 group 17±4 Comparative Example 1 62±5 Inactivation Example 2 Group 28±6

[0060] Experiment 2 Application of Lactobacillus paracasei LPc-HF46 in improving concentration

[0061] SPF level healthy Kunming mice selected for the experiment were 5 weeks old, and the body weight of the 50 male mice was uniform, with an initial body weight of 22±2.7 g, which were purchased from Beijing HFK Bioscience Co., Ltd. In order to adapt the mice to the surrounding environment, the 50 mice were adaptively fed for one week, and the feeding conditions were: humidity 4%, constant temperature 24±2℃, black night / white day cycle, free water and food.

[0062] Experimental grouping and model construction:

[0063] The 50 mice were randomly divided into 5 groups, 10 mice in each group, and ear clipping was used for marking.

[0064] Except for the normal group, which was free to eat the basic feed and water without any intervention, the mice were observed daily, and the body weight was measured and the feces were collected every week. The remaining four groups were free to eat the basic feed and water, and at the same time, the mice were injected with scopolamine hydrobromide 3 mg / kg intraperitoneally, once a day, for 7 consecutive days, to construct a mouse hyperactivity model. The activity, diet and response of the mice were observed 30 minutes after daily injection. After the modeling was completed, the remaining three groups were treated for 14 days: live Example 2 group: free to eat the basic feed and water, and 1% of the live state of Lactobacillus paracasei LPc-HF46 was added to the feed. Comparative Example 1 group: free to eat the basic feed and water, and 1% of the live state of Lactobacillus paracasei PC-01 powder was added to the feed. Inactivated Example 2 group: free to eat the basic feed and water, and 1% of the inactivated state of Lactobacillus paracasei LPc-HF46 powder was added to the feed.

[0065] Autonomous activity frequency determination: first, the mice in each group were placed in the autonomous activity instrument for 10 minutes to adapt to the environment, and then the mice in each group were placed in the autonomous activity instrument in turn for 10 minutes. The horizontal activity frequency and vertical activity frequency of the mice in the last 5 minutes were recorded, and the results are shown in Table 1. Figure 2

[0066] Scopolamine belongs to M-anticholinergic drugs, which can compete with acetylcholine to bind M receptors after being injected into the body, specifically block cholinergic synapses, and transfer information from the first level of memory to the second level of memory, so that the specific sensory afferent is blocked, thereby interfering with the ability of animals to obtain, store and reappear new information, causing animals to have poor concentration, inattention and unconscious action, etc. In this experiment, scopolamine was injected intraperitoneally into mice, and after 7 days of injection, the mice had significantly increased autonomous activity and sluggish response, indicating that the mouse hyperactivity model was successfully constructed. According to the results in Table 1, after treatment with live or inactivated Lactobacillus paracasei LPc-HF46, the autonomous activity frequency (horizontal movement frequency and vertical movement frequency) of the hyperactivity mice was significantly reduced. Figure 2

[0067] ​​Experiment 3 Application of Lactobacillus paracasei LPC-HF46 in promoting growth

[0068] Select 40 21-day-old (weaned) male ICR mice from Beijing HFK Bioscience Co., Ltd. To adapt the mice to the surrounding environment, the 40 mice were adaptively fed for one week, and the feeding conditions were: humidity 4%, constant temperature 24±2°C, black night / white day cycle, free water and food.

[0069] Experimental grouping and model construction:

[0070] The 40 mice were randomly divided into 4 groups, 10 mice in each group, and ear clipping was used for marking.

[0071] Except for the normal group, which was free to eat the basic feed and water without any intervention, the other three groups were fed with bacteria powder for 28 days: live Example 2 group: free to eat basic feed and water, with 1% live Lactobacillus paracasei LPC-HF46 feed added to the feed. Comparative Example 1 group: free to eat basic feed and water, with 1% Lactobacillus paracasei PC-01 bacteria powder in live state added to the feed. Inactivated Example 2 group: free to eat basic feed and water, with 1% inactivated Lactobacillus paracasei LPC-HF46 bacteria powder added to the feed.

[0072] The mice were sacrificed by cervical dislocation, the attached soft tissue was removed with a scalpel, and the bilateral femurs were separated. The left femur was labeled and placed in a sealed bag, and stored at -20°C.

[0073] Femur length: the length of the femur to be measured was measured and recorded using a vernier caliper.

[0074] Bone radiodensity: the femur sample at -20°C was taken out and wiped dry with absorbent paper. The bone density was detected and analyzed by dual-energy X-ray bone densitometer. Start the small animal bone density measuring instrument and the specially designed software analysis system. First, use the debugging mold to calibrate the machine. After calibration, remove the mold, place the femur sample in the instrument, keep all test samples in the same position, and start testing (test mode set to fast scan, high-energy parameter of scan condition is 80kVp / 1.0mA, low-energy parameter is 55kVp / 1.25mA). After testing, analyze the picture, select the required analysis area (ROI), analyze the bone density value, and save the numerical result.

[0075] According to the data in Table 2 and Figure 3 The femur length of the normal growing mice was 13.3±0.4mm, and feeding with Lactobacillus paracasei PC-01 did not promote the growth of mice, while feeding with Lactobacillus paracasei LPC-HF46, whether live or inactivated, effectively promoted the growth of mice and improved bone density.

[0076] Table 2

[0077] Group Femur length (mm) Femur density (g / cm 2 ) Normal group 13.3±0.4 0.10±0.02 Live bacteria example 2 group 16.2±0.5 0.16±0.03 Comparative Example 1 13.9±0.4 0.11±0.02 Inactivation Example 2 Group 15.7±0.3 0.14±0.01

[0078] The above embodiments only express the specific implementation of the present application, which is described in more detail and in more detail, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A Lactobacillus paracasei LPc-HF46 for improving memory and concentration and promoting children's growth, characterized in that: It is deposited in the China Center for Type Culture Collection with the deposit number CCTCCNO: M 20241569 and the deposit date is July 15, 2024.

2. Application of Lactobacillus paracasei LPc-HF46 according to claim 1 in preparing products for improving memory and concentration.

3. the application of Lactobacillus paracasei LPc-HF46 according to claim 1 in preparation promotion aspect children's growth goods.

4. application according to claim 2 or 3, wherein Lactobacillus paracasei LPc-HF46 is in a viable bacteria or inactivated state.

5. the preparation method of the bacterial powder of Lactobacillus paracasei LPc-HF46 with improving memory and concentration and promoting children's growth according to claim 1 is characterized in that Here are the steps: S1. Melt a glycerol tube of Lactobacillus paracasei LPc-HF46 stored at -20°C and inoculate 1 mL into 40-110 mL of LMRs liquid culture medium. Incubate at 31-37°C for 12-16 h, centrifuge and wash three times with sterile physiological water. Adjust the bacterial suspension to an appropriate concentration with sterile water to prepare a seed suspension for later use. S2. transferring the seed suspension to the fermentation broth, and fermenting with aeration at 31-37° C. and 100-130 rpm for 36-72 hours to obtain a fermentation broth; S3. Collect 20-30 ml of the fermented liquid and place it in a sterile 50 ml centrifuge tube for centrifugation. Discard the supernatant and collect the bacterial sludge. S4. Collect the centrifuged bacterial cells, add a bacterial slurry protective agent prepared by 21% milk powder, 15% trehalose, 2% glycerol, 5% xylo-oligosaccharide and ultrapure water, and vortex mix to obtain a freeze-dried bacterial suspension. Let it stand at room temperature for 1 hour to allow the protective agent and the bacterial cells to fully fuse to obtain a freeze-dried bacterial suspension. S5, the freeze-dried bacterial suspension was pre-frozen in a -80 ℃ refrigerator for 2 h, and immediately placed in a freeze dryer after being taken out to avoid damage to the bacteria due to a sudden rise in temperature. The sample was placed in a freeze dryer and continued to freeze-dry for 24 h to obtain Lactobacillus paracasei LPc-HF46 bacterial powder, wherein the content of Lactobacillus paracasei LPc-HF46 strain was 10 10 -10 12 CFU / g, the freeze dryer should be turned on in advance to reduce the freezing temperature to -55°C and the vacuum degree to 1000Pa during operation.

6. The method according to claim 5, characterized in that: The MRS liquid culture medium in step S1 is specifically: peptone 10 g / L, beef extract 10 g / L, yeast powder 5 g / L, dipotassium hydrogen phosphate 2 g / L, tricitrate 2 g / L, sodium acetate 5 g / L, Tween-80 1 mL / L, magnesium sulfate 0.2 g / L, sulfuric acid 0.05 g / L, glucose 20 g / L, pH = 6.5, sterilized at 121 ° C for 20 min.

7. The method according to claim 5, characterized in that: In step S2, the ratio of the air volume to the tank volume is 1:0.5-1 (v / vm).

8. The method according to claim 5, wherein: The centrifugation conditions in step S3 are 4000 r / min, 20 min, 4° C., or 6000 r / min, 10 min, 4° C.; the volume of the protective agent added in step S4 is 1 / 5 of the culture medium before centrifugation. 9 . A food or medicine comprising the Lactobacillus paracasei LPc-HF46 according to claim 1 . A postbiotic preparation comprising the Lactobacillus paracasei LPc-HF46 according to claim 1.

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