Phytobacterium plantarum with double functions of delaying senescence and prolonging life and application thereof

Abstract

The invention belongs to the technical field of microorganisms, and relates to a plant lactobacillus with double functions of delaying senescence and prolonging life and application of the plant lactobacillus. The preservation number of the lactobacillus plantarum Q7-1 is CCTCC (China Center for Type Culture Collection) NO: M2022517, and the preservation number of the lactobacillus plantarum Q7-1 is CCTCC NO: M2022517. The invention protects the application of the plant lactobacillus Q7-1 and the microbial preparation thereof in preparation of a product with the efficacy of prolonging the life and / or delaying senescence. Aiming at the potential of the probiotics for delaying senescence and prolonging the life, the invention accurately screens out a plant lactobacillus strain with obvious dual functions of resisting senescence and prolonging the life through a specific screening method and standard; in-depth study is carried out by applying a transcriptomics technical means, the effect of the plant lactobacillus strain in nematode bodies is verified, the anti-aging and life-prolonging functions of the plant lactobacillus Q7-1 are defined, and a theoretical basis is provided for research, development and application of anti-aging and life-prolonging probiotic products.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microbial technology, and specifically relates to a strain of Bacillus lactis with the functions of delaying aging and prolonging life and application thereof. BACKGROUND

[0002] Aging is a complex and irreversible physiological process, which is accompanied by the gradual decline of the functions of multiple organs and systems of the body. At present, under the dual background of the intensification of population aging and the upgrading of health needs, delaying aging and improving the quality of life through scientific means have become an urgent need in today's society.

[0003] Anti-aging and life extension are two different dimensional problems, and the goals and effects of the two are different. Anti-aging aims to slow down the degradation of body functions and maintain a healthy state, i.e. a high-quality self-care life stage, and the core is to "compress the period of life with disease and prolong the period of healthy life" (delay the occurrence of disease). Life extension focuses on breaking through the existing upper limit of life span, and directly prolongs the overall survival time of individuals through biomedical intervention (such as stem cell regeneration, gene modification), and the core is to "break through the survival period limit". Anti-aging does not necessarily prolong life, and life extension does not necessarily improve the quality of life. At present, only in special groups such as centenarians can the synergy of anti-aging and life extension be achieved.

[0004] Probiotics are a class of active microorganisms that are beneficial to the health of the host. Compared with traditional anti-aging drugs, probiotics as natural products have the advantages of high safety, small side effects, etc., and have broad application prospects in the field of delaying aging. With the gradual expansion of the number of the world's aging population, if a special probiotic that can both delay aging and prolong life can be screened, it will not only lay the foundation for the research and development of special dietary supplements for prolonging life, but also has important significance for human beings to prolong healthy life and achieve healthy aging.

[0005] However, the current research on probiotics delaying aging has many shortcomings: first, there is a lack of special probiotic strains with the dual functions of delaying aging and prolonging life: due to the unclear understanding of the concepts of delaying aging and prolonging life, there are various probiotic products on the market, but most of them focus on regulating intestinal flora balance, enhancing immunity and other conventional functions, and there are basically no probiotic strains that can both delay aging and prolong life, which cannot meet the needs of people to achieve delaying aging and prolonging life through probiotics. Second, the role of existing research on probiotics in delaying aging and prolonging life is not clear: due to the unclear understanding of the concepts of delaying aging and prolonging life, most of the related probiotic articles or patents are positioned in delaying aging, and there are basically no probiotic strains with the dual functions of delaying aging and prolonging life, and the existing research is still in the exploratory stage. The insufficiency of such research makes consumers lack scientific basis and confidence when using probiotic products. Third, the product form of probiotics delaying aging is relatively single: the product form of probiotics delaying aging on the current market is relatively single, mainly traditional dosage forms such as capsules and powders, which have many limitations in use scenarios, taste experience and convenience, and it is difficult to meet the needs of consumers.

[0006] The above shortcomings limit the application and promotion of probiotics in the development of products for delaying aging and prolonging life, and it is particularly important to study probiotics with clear dual functions of delaying aging and prolonging life and clear mechanisms.

[0007] Based on this, the inventors have screened a plant lactiplantibacillus with the dual functions of delaying aging and prolonging life, and have verified its role, which provides core strain resources and theoretical basis for the development of probiotic products for delaying aging and prolonging life. SUMMARY

[0008] The purpose of the present application is to solve the above-mentioned problems in the prior art, and a plant lactiplantibacillus with the dual functions of delaying aging and prolonging life and its application are proposed. In view of the current situation that the product form of probiotics delaying aging on the market is relatively single, the positioning of delaying aging or prolonging life is unclear, and it is difficult to meet the needs of consumers, the present application develops a variety of products including probiotic agents, probiotic fermented milk and the like, to meet the individual needs of different consumers, and the products have the dual functions of anti-aging and life prolonging, which have obvious market competitiveness.

[0009] The technical scheme of the present application is as follows:

[0010] The present application provides a plant lactiplantibacillus Q7-1, whose preservation number is CCTCC NO: M 2022517.

[0011] The present application provides a microbial preparation comprising the Lactobacillus plantarum Q7-1.

[0012] The present application protects the use of the Lactobacillus plantarum Q7-1 or the microbial preparation in the preparation of a product with the function of delaying aging and / or prolonging life.

[0013] Further, the product includes food, medicine, etc.

[0014] The present application also protects the use of the Lactobacillus plantarum Q7-1 or the microbial preparation in the preparation of a fermented food, which includes fermented dairy products, fermented beverages and fermented fruit and vegetable products.

[0015] Further, the preparation method of the fermented food includes the following steps: mixing the Lactobacillus plantarum Q7-1 or the microbial preparation thereof with food raw materials, and performing fermentation treatment to obtain the fermented food.

[0016] The present application protects a Lactobacillus plantarum fermented dairy product with the function of delaying aging and / or prolonging life, which is prepared by fermentation of Lactobacillus plantarum Q7-1, and the preparation method includes the following steps:

[0017] The Lactobacillus plantarum Q7-1 is added to fresh milk or reduced milk, and cultured at 37℃ for 24-36h, and the obtained bacterial solution is added to sterilized pure milk, and fully stirred and mixed, and then fermented at 37-42℃ for 8-12h to obtain the Lactobacillus plantarum fermented dairy product.

[0018] Further, in the fermented dairy product, the viable bacterial amount of Lactobacillus plantarum Q7-1 is greater than 1×10 9 CFU / ml.

[0019] The present application also protects a Lactobacillus plantarum fermented fruit and vegetable juice product with the function of delaying aging and / or prolonging life, which is prepared by fermentation of Lactobacillus plantarum Q7-1, and the preparation method includes the following steps:

[0020] The Lactobacillus plantarum Q7-1 is cultured in MRS medium at 37℃ for 22-30h, and the obtained bacterial solution is inoculated into fruit and vegetable juice which is sterilized at 135-140℃ and then cooled to room temperature, and fully stirred and mixed, and then fermented at 37-42℃ for 8-12h to obtain the Lactobacillus plantarum fermented fruit and vegetable juice product.

[0021] Further, in the fermented fruit and vegetable juice product, the viable bacterial amount of Lactobacillus plantarum Q7-1 is greater than 1×10 9 CFU / ml.

[0022] Biological material preservation information:

[0023] Lactobacillus plantarum Q7-1 was preserved in China Center for Type Culture Collection on May 5, 2022, with a preservation number of CCTCC NO: M 2022517 and a preservation address of Wuhan University, Wuhan, China.

[0024] It should be noted that the National Health Commission issued Announcement No. 4 in August 2022, which renamed Lactobacillus plantarum as Lactiplantibacillus plantarum according to the changes in the classification status of international bacteria.

[0025] The beneficial effects of the present application are:

[0026] (1) The present application precisely screens Lactiplantibacillus plantarum strains with the dual functions of significantly delaying aging and prolonging lifespan through specific screening methods and standards; for the potential of probiotics to delay aging and prolong lifespan, the present application uses transcriptomic technology to deeply study and verify the effects of the Lactiplantibacillus plantarum strain in C. elegans, and confirms that the Lactiplantibacillus plantarum strain Q7-1 protected by the present application has anti-aging and lifespan-prolonging functions, providing a theoretical basis for the research and application of anti-aging and lifespan-prolonging probiotic products.

[0027] (2) The Lactiplantibacillus plantarum Q7-1 screened by the present application can significantly prolong the lifespan of C. elegans and effectively delay the aging process of C. elegans; it can maintain the stability of the pharyngeal pump function of C. elegans, slow down the decline of feeding and metabolic function caused by aging; it can delay the decline of muscle function in old C. elegans, helping to maintain the exercise capacity of C. elegans during the aging process; it can reduce the accumulation of lipofuscin in C. elegans; it can enhance the antioxidant stress resistance and protein homeostasis maintenance ability of C. elegans by regulating the expression of multiple aging-related genes, while inhibiting adverse reactions such as cell stress and apoptosis, thereby playing a role in delaying the aging of C. elegans at the molecular level. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Survival curve of C. elegans provided for Test Example 2;

[0029] Figure 2 Pharyngeal pump frequency graph of C. elegans provided for Test Example 3;

[0030] Figure 3 Exercise capacity level of C. elegans provided for Test Example 4;

[0031] Figure 4 Lipofuscin fluorescence intensity of C. elegans during the aging process provided for Test Example 5;

[0032] Figure 5 Regulation of aging-related genes for test example 6;

[0033] Figure 6 Potential action pathways of C. elegans aging process for test example 6. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be apparently and completely described in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the present application.

[0035] In order to further understand the present application, the present application will be further described in combination with the drawings and embodiments.

[0036] The experimental methods in the following embodiments are all conventional methods, and are carried out according to the techniques or conditions described in the literature in the art or according to the product instructions, unless otherwise specified. The materials, reagents and the like used in the following embodiments can be obtained from commercial channels, unless otherwise specified.

[0037] Example 1

[0038] Isolation and culture of Lactobacillus plantarum Q7-1

[0039] The strain is isolated from Qinghai yak yogurt. The specific isolation and screening method is as follows:

[0040] The Qinghai yak yogurt sample is diluted 10 times and then separated by coating method. 100 μL is coated on a semi-selective medium plate, and MRS-cys medium added with X-gal is used for 48 h culture at 37°C, and then 4 h standing in air. The blue colonies are picked by inoculation loop for purification. The isolated strain is stored in glycerol suspension at -80°C for standby.

[0041] The 16S rDNA gene sequence of the isolated strain is subjected to PCR amplification by using universal primers 27f (5'-AGAGTTTGATCCTGGCTCAG-3') (SEQ ID NO: 2) and 1492r (5'-GGTTACCTTGTTACGACTT-3') (SEQ ID NO: 3) of Lactobacillus plantarum 16S rDNA sequence, and the PCR product is sent to Shengong Bioengineering (Shanghai) Co., Ltd. for sequencing. The full-length 16S rDNA sequence is shown as SEQ ID NO: 1.

[0042] The obtained sequence was analyzed, and the results showed that the strain Q7-1 was Lactiplantibacillus plantarum. It was preserved in China Center for Type Culture Collection, and the preservation date was May 5, 2022, and the preservation number was CCTCC NO: M 2022517.

[0043] Example 2

[0044] The present embodiment provides a Lactiplantibacillus plantarum fermented dairy product and a preparation method thereof.

[0045] The prepared Lactiplantibacillus plantarum fermented dairy product has the effects of delaying aging and prolonging life.

[0046] The preparation method comprises the following steps:

[0047] The Lactiplantibacillus plantarum Q7-1 is cultured in fresh milk or reduced milk at 37 DEG C for 30 hours for standby;

[0048] The bacterial liquid obtained in the above step is inoculated into sterilized pure milk, and after being fully stirred and mixed uniformly, it is placed at 40 DEG C for fermentation for 10 hours to prepare a fermented dairy product.

[0049] The prepared probiotic fermented dairy product is diluted by several times, and then plate counting is performed, and the viable bacterial amount of the Lactiplantibacillus plantarum Q7-1 is greater than 1x10 9 CFU / ml.

[0050] Example 3

[0051] The present embodiment provides a Lactiplantibacillus plantarum fermented fruit and vegetable juice product and a preparation method thereof.

[0052] The prepared Lactiplantibacillus plantarum fermented fruit and vegetable juice product has the effects of delaying aging and prolonging life.

[0053] The preparation method comprises the following steps:

[0054] The Lactiplantibacillus plantarum Q7-1 is cultured in MRS medium at 37 DEG C for 24 hours to obtain a bacterial liquid for standby;

[0055] Fresh vegetables such as carrots and fresh fruits such as strawberries are selected, washed, and juiced. After the raw materials after juicing are subjected to high-temperature instantaneous sterilization at 135-140 DEG C for 1-2 seconds, they are immediately cooled to room temperature. The bacterial liquid obtained in the above step is inoculated into sterilized fruit and vegetable juice, fully stirred and mixed uniformly, and then placed at 40 DEG C for fermentation for 10 hours to prepare a fermented fruit and vegetable juice product.

[0056] The prepared probiotic fermented fruit and vegetable juice product is diluted by several times, and then plate counting is performed, and the viable bacterial amount of the Lactiplantibacillus plantarum Q7-1 is greater than 1x10 9 CFU / ml.

[0057] Culture and synchronization of Caenorhabditis elegans in experimental example 1

[0058] Caenorhabditis elegans is widely selected as a classic aging model due to its unique biological characteristics. It has the advantages of short life cycle, strong reproductive capacity, transparent body easy to observe, clear genetic background, etc. In addition, 40-60% of the genes in Caenorhabditis elegans are homologous to humans, which enables the discovery of aging delay mechanisms from Caenorhabditis elegans model to provide important biological clues and intervention targets for human aging research.

[0059] (1) Preparation of nematode growth medium (NGM): Add 3 g of sodium chloride, 20 g of agar powder, 2.5 g of peptone, and 970 ml of deionized water to a conical flask in sequence, cover with tin foil paper, sterilize at 121°C for 20 min, and cool to 55°C in a water bath. Under sterile conditions, add the following sterilized solutions: 25 ml of 1 mol / L potassium phosphate buffer, 1 ml of 1 mol / L calcium chloride solution, 1 ml of 5 mg / ml cholesterol solution, and 1 ml of 1 mol / L magnesium sulfate solution. Mix gently, pour the plate, and store at 4°C after the plate solidifies.

[0060] (2) Preparation of nematode culture buffer (M9): Add 3 g of potassium dihydrogen phosphate, 5 g of sodium chloride, and 15.12 g of dodecahydrate sodium phosphate hydrogen phosphate in sequence, add distilled water to 1 L, sterilize at 121°C for 15 min, and mix 1 ml of 1 mol / L magnesium sulfate solution under sterile conditions after cooling to room temperature. Mix well and store for future use.

[0061] (3) Preparation of nematode lysis solution: Mix 5 mol / L sodium hydroxide solution, 5% sodium hypochlorite solution, and M9 buffer in a ratio of 1:1:1 and shake well. Prepare fresh each time.

[0062] (4) Culture of nematode food bacteria (Escherichia coli OP50): Pick a single colony of Escherichia coli OP50 in 10 ml of LB liquid medium, incubate at 37°C with 120 rpm shaking for 8-12 h, and when the OD 600 is 1.0-1.2, add 200 μl of bacterial solution to the NGM plate and spread evenly. Incubate at 37°C for 12 h and store at 4°C for future use.

[0063] (5) Cultivation of nematodes: Caenorhabditis elegans was placed on NGM plates coated with Escherichia coli OP50 and cultured in a constant temperature incubator at 20℃. Every 3 days, nematodes were picked and passaged onto fresh NGM plates coated with Escherichia coli OP50 to ensure that the nematodes had sufficient food and to maintain their activity.

[0064] (6) Synchronization of nematodes: Plates containing adult nematodes and a large number of eggs after passage were washed with M9 buffer for nematode synchronization. After washing, the nematodes were collected in centrifuge tubes, centrifuged at 800×g for 1 min, the supernatant was discarded, and the nematode bodies were collected. 1 mL of M9 buffer was added, and the nematode bodies were washed again by centrifugation, removing as much supernatant as possible. 1 mL of fresh nematode lysis buffer was added, and the mixture was immediately vortexed for 10 s. The nematode bodies were observed under a stereomicroscope. When most of the nematode bodies broke apart and the eggs inside were exposed, the mixture was immediately centrifuged at 800×g for 1 min, the supernatant was discarded, and the precipitate was collected. The precipitate was then washed three times with M9 buffer. 200 μl of M9 buffer was added to the precipitate for resuspending, and the suspension was transferred to a blank NGM plate. The lysis was observed under a stereomicroscope. A large number of eggs and some fragmented nematode bodies were visible under the microscope, indicating successful lysis. The lysed eggs were transferred to a 20℃ incubator for incubation in the next experiment.

[0065] Experiment Example 2: Lifetime Screening Experiment of Caenorhabditis elegans

[0066] (1) Preparation of improved nematode growth medium (mNGM)

[0067] Before pouring NGM medium onto plates, add filtered and sterilized 5-fluorodeoxyuridine and carbenicillin to final concentrations of 50 mg / L and 1 mmol, respectively. Mix well, pour onto plates, and allow to solidify. Let the plates sit at room temperature for 2 days to allow moisture to evaporate. Then, spread the medium on a plating sheet or store it in a 4°C refrigerator. Use within one month.

[0068] (2) Experimental grouping

[0069] Because using probiotics alone to replace OP50 as food for nematodes can induce selective preference in the nematodes, leading to stunted development, this invention uses a 1:1 mixture of *Lactiplantibacillus plantarum* Q7-1 and *Escherichia coli* OP50 as the experimental group, and *Escherichia coli* OP50 as the control group. The specific procedures are as follows:

[0070] The Q7-1 strain was expanded using MRS liquid medium, and the OP50 strain was expanded using LB liquid medium, and was activated twice in succession to ensure the activity and stability of the strains. The activated Q7-1 bacterial liquid and OP50 bacterial liquid were each concentrated by 10 times, and then mixed uniformly at a ratio of 1:1 to prepare Q7-1 mixed concentrated bacterial liquid. 200 μl of the Q7-1 mixed concentrated bacterial liquid and the OP50 concentrated bacterial liquid were each uniformly coated on the prepared mNGM plate, and were cultured at 37°C for 24 h and 12 h, respectively, and were stored at 4°C for standby use.

[0071] (3) Life span screening experiment

[0072] The nematodes after being synchronized for 48 h were observed under a stereomicroscope, and the L4 stage hermaphrodites with transparent half-moon-shaped reproductive openings were picked up using a platinum spatula and were placed on mNGM plates coated with different test bacteria, 35 nematodes were picked up per plate, and 3 plates were picked up for each test bacteria. The plates were placed in a 20°C incubator for standard life span experiments.

[0073] The survival status of the nematodes was observed every day, and if the nematodes did not have a movement response to the light touch of the platinum spatula, the nematodes were considered to have died, were picked out of the plate, and the number of dead nematodes was recorded. The missing, in-vivo hatching, and unnatural death nematodes were excluded. The experiment was ended when all the nematodes died. Each group of treatment was repeated three times.

[0074] (4) Experimental results

[0075] The life span and survival rate of C. elegans were used as targets to evaluate the effect of P. lactis Q7-1 on the aging process and survival time of nematodes, and the survival curve results are shown in Figure 1 .

[0076] The average life span of the control group nematodes was 16.38 ± 0.46 d, and the average life span of the experimental group nematodes after intervention by P. lactis Q7-1 was extended to 19.24 ± 0.67 d, with an extension rate of 17.46% (P < 0.001). The median life span of the control group nematodes was 16.00 ± 0.41 d, and the median life span of the experimental group nematodes after intervention by P. lactis Q7-1 was extended to 18.00 ± 0.44 d, with an extension rate of 12.5% (P < 0.001). From the survival curve, the survival rate of the experimental group nematodes in the later stage was significantly higher than that of the control group, and on the 22nd day, the survival rate of the experimental group was 22.04 ± 7.79%, and that of the control group was only 8.10 ± 1.66% (P < 0.05).

[0077] The above results show that P. lactis Q7-1 can significantly prolong the life span of nematodes and effectively delay the aging process of C. elegans.

[0078] Test Example 3 Determination of the pharyngeal pump frequency of C. elegans

[0079] (1) Determination experiment

[0080] Randomly pick the synchronized L4 stage nematodes on the mNGM plates of different test bacteria, pick 30 per plate, pick 3 plates for each bacteria, and culture under 20°C culture conditions. Observe the change of nematode pharyngeal pump frequency at the 1st, 7th and 15th days of intervention. Randomly pick 10 nematodes after intervention on 10 blank NGM plates, place the plates under a biological microscope, magnify 50 times, and record the number of pharyngeal pump activities within 1 minute as the pharyngeal pump frequency.

[0081] (2) Experimental results

[0082] The pharyngeal pump frequency reflects the feeding function and metabolic state of nematodes. The influence of Lactiplantibacillus plantarum Q7-1 on the related physiological functions of nematodes in the aging process is evaluated by determining the pharyngeal pump frequency.

[0083] From Figure 2 As can be seen, the pharyngeal pump frequency of the control group gradually decreased with the increase of nematode age, from the initial 233.80±19.67 pump / min to 152.60±32.90 pump / min at the 7th day, and to 71.86±12.62 pump / min at the 15th day. After intervention by strain Q7-1, the experimental group also decreased, but the pharyngeal pump frequency at the 15th day was 108.00±21.00 pump / min, with a significantly smaller decrease than the control group (P<0.05).

[0084] The above results show that Lactiplantibacillus plantarum Q7-1 can maintain the stability of the pharyngeal pump function of Caenorhabditis elegans, slow down the decline of feeding and metabolic functions caused by aging, and help nematodes maintain good physiological state and delay the aging process.

[0085] Test Example 4 Determination of the movement ability of Caenorhabditis elegans

[0086] (1) Determination experiment

[0087] Randomly pick the synchronized L4 stage nematodes on the mNGM plates of different test bacteria, pick 30 per plate, pick 3 plates for each bacteria, and culture under 20°C culture conditions. Observe the change of nematode pharyngeal pump frequency at the 1st, 7th and 15th days of intervention. Movement ability is determined by observing the movement trajectory and moving speed of nematodes, which is divided into four states: A-Normal locomotion, nematodes show active movement ability; B-Uncoordinated / Sluggish, nematodes only move when touched or have uncoordinated movement without touch; C-Cannot move body, nematodes only have head swing and body stiffness when responding to touch; D-Dead, nematodes are dead.

[0088] (2) Experimental results

[0089] The movement ability is a key indicator for evaluating the aging degree of nematodes. The movement ability of nematodes in the aging process is reflected by four states A-D, and the influence of B. plantarum Q7-1 on the movement function of nematodes is evaluated to determine whether it can delay the decline of movement ability caused by aging.

[0090] As shown in Figure 3 , there is no obvious difference in the movement ability of nematodes between the control group and the experimental group in the initial young stage. By the 15th day, the proportion of the four movement states A-D in the control group is 0%, 11%, 27%, and 62%, respectively, and the proportion of the four movement states A-D in the experimental group is 12%, 26%, 32%, and 30%, respectively. After the intervention of strain Q7-1, the proportion of nematodes with spontaneous active movement ability in the experimental group is much higher than that in the control group, indicating that B. plantarum Q7-1 can delay the muscle function decline of old nematodes and help maintain the movement ability during the aging process of nematodes.

[0091] Test Example 5 Lipofuscin accumulation of C. elegans

[0092] (1) Measurement of experiment

[0093] Randomly pick L4 stage nematodes after synchronization on mNGM plates coated with different test bacteria, pick 50 per plate, pick 3 plates, and place the plates in a 20°C incubator. Observe on the 1st, 7th, and 15th day of intervention. Wash the test nematodes with M9 buffer 3 times, then fix them on a 2% agarose slide with 25 mmol / L levodopa, use an electric fluorescence microscope DAPI channel for fluorescence imaging, and observe the level of lipofuscin accumulation in nematodes.

[0094] (2) Experimental results

[0095] Lipofuscin is a non-degradable pigment particle produced during the aging process of nematodes, and its accumulation is closely related to the degree of cell aging. It is often regarded as an important marker substance for measuring the aging process of cells. By observing the accumulation of lipofuscin in nematodes, the influence of B. plantarum Q7-1 on the aging of nematode cells is evaluated.

[0096] The results are shown in Figure 4 , it is found that the fluorescence intensity of lipofuscin in the control group and the experimental group shows a gradually increasing trend over time during the aging process of nematodes, indicating that the accumulation of oxidative products lipofuscin is gradually increasing. The fluorescence intensity of lipofuscin in the experimental group after intervention with strain Q7-1 is significantly lower than that in the control group, indicating that B. plantarum Q7-1 can reduce the accumulation of lipofuscin in C. elegans, and thus delay the aging process of nematode cells.

[0097] Test Example 6 Transcriptomic verification of C. elegans

[0098] (1) RNA extraction and quality detection

[0099] The synchronized L4 stage nematodes were transferred to mNGM plates coated with different test bacteria for intervention. After 5 days of intervention, the nematodes in the experimental and control groups were rinsed with M9 solution and collected into sterile enzyme-free EP tubes for RNA extraction. RNA was isolated using the TIANamp TRIzol Total RNA Extraction Kit, and the RNA concentration and quality were identified using a NanoDrop spectrophotometer. The RNA integrity was evaluated according to the results of agarose gel electrophoresis.

[0100] (2) RNA library construction and sequencing

[0101] The extracted RNA was subjected to Illumina library construction. The library was quality evaluated using an Agilent Bioanalyzer, and sequenced using an Illumina Xplus sequencing platform to generate raw data. Low-quality data in the raw data was removed using Fastp software. The effective data obtained was aligned to the C. elegans genome using HISAT2, and then subjected to transcriptome data assembly and gene expression quantification using StringTie. Differential gene analysis was performed using DEseq2, with a differential gene screening threshold of log2|foldchange|>1 and P-adjust<0.05. GO and KEGG analysis was performed on the differential genes to enrich differential pathways.

[0102] (3) Verification results

[0103] To reveal the mechanism of B. plantarum Q7-1 in delaying the aging of C. elegans from the molecular level, transcriptomic analysis was performed on the experimental and control nematodes. The experimental results are shown in Figure 5 and Figure 6 .

[0104] Compared with the control group, the expression of 8099 genes in the experimental group nematodes changed significantly (log2|foldchange|>1, P-adjust<0.05), of which 3763 genes were up-regulated and 4336 genes were down-regulated. Functional enrichment analysis found that the up-regulated genes were mainly involved in aging-related pathways such as antioxidant stress (e.g., gpx-1, gpx-7, etc.), protein homeostasis maintenance (e.g., hsp-16.1, hsp-70, etc.), and the down-regulated genes were mostly related to adverse reactions such as cell stress and apoptosis.

[0105] The above results show that B. plantarum Q7-1 can delay the aging of nematodes from the molecular level by regulating the expression of multiple aging-related genes, enhancing the antioxidant stress resistance and protein homeostasis maintenance ability of nematodes, and inhibiting adverse reactions such as cell stress and apoptosis.

[0106] The above description is only the preferred embodiments of the present application, and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalent features. Any modification, equivalent replacement, modification, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A strain of Lactiplantibacillus plantarum Q7-1, with accession number CCTCCNO: M 2022517.

2. A microbial preparation, characterized in that, It includes Lactobacillus plantarum Q7-1 as described in claim 1.

3. The use of the *Lactobacillus plantarum* Q7-1 as described in claim 1 or the microbial preparation as described in claim 2 in the preparation of products with anti-aging and / or life-extending effects.

4. The application according to claim 3, characterized in that, The products include food or medicine.

5. The application of *Lactobacillus plantarum* Q7-1 as described in claim 1 or the microbial preparation as described in claim 2 in fermented foods, characterized in that... The fermented foods include fermented dairy products, fermented beverages, and fermented fruit and vegetable products.

6. The application according to claim 5, characterized in that, The preparation method of the fermented food includes the following steps: mixing Lactobacillus plantarum Q7-1 or its microbial preparation with food raw materials and carrying out fermentation treatment to obtain the fermented food.

7. A plant-based fermented dairy product with anti-aging and / or life-extending functions, characterized in that, The fermented dairy product is obtained by fermentation with Lactobacillus plantarum Q7-1, and its preparation method includes the following steps: Add *Lactobacillus plantarum* Q7-1 to fresh milk or reconstituted milk and incubate at 37°C for 24–36 hours. Add the resulting bacterial solution to sterilized pure milk, stir thoroughly, mix evenly, and then let it ferment at 37–42°C for 8–12 hours to obtain *Lactobacillus plantarum* fermented dairy products.

8. The fermented dairy product according to claim 7, characterized in that, In the fermented dairy product, the viable count of *Lactobacillus plantarum* Q7-1 is greater than 1 × 10⁻⁶. 9 CFU / ml.

9. A plant-based fermented fruit and vegetable juice product with anti-aging and / or life-extending functions, characterized in that, The fermented fruit and vegetable juice product is obtained by fermentation with Lactobacillus plantarum Q7-1, and its preparation method includes the following steps: Lactobacillus plantarum Q7-1 was cultured in MRS medium at 37℃ for 22–30 h. The resulting bacterial solution was inoculated into fruit and vegetable juice that had been sterilized at 135–140℃ and cooled to room temperature. After thorough mixing, the mixture was allowed to ferment at 37–42℃ for 8–12 h to obtain fermented fruit and vegetable juice products made from Lactobacillus plantarum.

10. The fermented fruit and vegetable juice product according to claim 9, characterized in that, In the fermented fruit and vegetable juice product, the viable count of *Lactobacillus plantarum* Q7-1 is greater than 1×10⁻⁶. 9 CFU / ml.

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