Veillonella enteritidis and its application

Abstract

The present invention provides a Veillonella enteritidis and an application thereof. The Veillonella enteritidis ( Veillonella enterica ) is deposited as GDMCC No: 65234. The present invention also provides a preparation containing the Veillonella enteritidis, a culture method, and the use of the Veillonella enteritidis as a marker microorganism or target in the preparation of a drug for screening diseases caused by the Veillonella enteritidis. The present invention analyzes the virulence genes and pathogenicity of the Veillonella enteritidis, indicating that it has the potential pathogenicity to aggravate inflammatory bowel disease, and compared with Veillonella parvum, the strain shows specificity in biological characteristics and pathogenicity, which has a new improvement in the understanding of the genus Veillonella in the intestine, and provides a new perspective and new direction for the study of the role of Veillonella in intestinal diseases such as IBD.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and specifically relates to Veillonella enteritidis and application thereof. Background Art

[0002] Veillonella Veillonella spp.) is a Gram-negative strict anaerobic bacterium with a diameter of 0.3-0.5 μm. It is bi-spherical, flake-like and short-chain-like under a microscope. It has no capsule, no flagella and no spores. It mainly colonizes the human oral cavity and intestine. There are currently 15 species in the genus, mainly Veillonella atypica , Veillonella caviae , Veillonella criceti , Veillonella dentistry , Veillonella dispar , Veillonella infantium , Veillonella magna , Veillonella montpellierensis , Veillonella nakazawae , Veillonella parvula , Veillonella ratti , Veillonella rodentium , Veillonella rogosae , Veillonella seminalis , Veillonella tobetsuensis These bacteria were first discovered in the oral cavity or have been confirmed to exist in large numbers in the oral cavity. The increased abundance of Veillonella in various parts of the body is often accompanied by the occurrence of diseases. For example, Veillonella in the oral cavity plays the role of an intermediate colonizer in the development of caries and periodontitis, and can help other pathogens colonize in the oral cavity; and the increased abundance of Veillonella in the intestine is accompanied by the occurrence of autoimmune liver disease and the progression of inflammatory bowel disease; disseminated Veillonella infection can lead to endocarditis, discitis, osteomyelitis and other diseases.

[0003] There are few reports on Veillonella associated with inflammatory bowel disease (IBD). The mainstream view is that during the onset of IBD, the patient's intestinal metabolome and microbiome undergo tremendous changes, and the resulting intestinal microenvironment is suitable for the growth of Veillonella, and that Veillonella in the oral cavity is transferred to the intestine in large quantities through ectopic colonization. In addition, Veillonella can use the large amount of lactic acid in the intestine of IBD patients as a carbon source for normal energy metabolism, or it can use elevated nitrates to start anaerobic respiration to obtain energy. A suitable environment helps Veillonella occupy more ecological niches, while an excessive amount of Veillonella will further promote intestinal inflammation, thus falling into a vicious cycle and causing symptoms to worsen. Summary of the invention

[0004] The purpose of the invention is to provide a Veillonella enteritidis and application thereof.

[0005] The present invention discovered a new species of Veillonella and explored the genomic characteristics and biological properties of the Veillonella. The inventors isolated and identified a new species of Veillonella from the feces of patients with inflammatory bowel disease, which was different from the previously reported species, and named it Veillonella enteritidis ( Veillonella enterica )Ser01. In order to ensure the scientific preservation and subsequent research of the strain, the inventors have preserved the above strains. The deposit date of the Veillonella enteritidis: October 8, 2024, the deposit unit: Guangdong Microbiological Culture Collection Center (GDMCC), the deposit unit address: 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou, Institute of Microbiology, Guangdong Academy of Sciences, classification name: Veillonella enteritidis ( Veillonella enterica ), with a deposit number of GDMCC No: 65234. In the subsequent description of the present invention, we will uniformly use the name "Veillonella enteritidis Ser01" to refer to this species.

[0006] In one aspect, the present invention provides a Veillonella enteritidis ( Veillonella enterica ), the deposit number of the Veillonella enteritidis is GDMCC No: 65234.

[0007] On the other hand, the present invention provides a Veillonella enteritidis preparation, wherein the Veillonella enteritidis preparation contains Veillonella enteritidis with a deposit number of GDMCC No: 65234.

[0008] According to a specific embodiment of the present invention, the Veillonella enteritidis preparation is an inactivated preparation or a live bacteria preparation.

[0009] According to a specific embodiment of the present invention, the Veillonella enteritidis preparation is a liquid preparation or a solid preparation.

[0010] In another aspect, the present invention provides a method for culturing the above-mentioned Veillonella enteritidis, the method comprising:

[0011] Veillonella enteritidis was inoculated into the culture medium at a culture temperature of 36-38°C and cultured anaerobicly.

[0012] According to a specific embodiment of the present invention, preferably, the culture temperature is 37°C.

[0013] According to a specific embodiment of the present invention, preferably, Veillonella enteritidis is inoculated into a culture medium, and the culture rotation speed is 120-200 rpm, more preferably 160-190 rpm, and further preferably 180 rpm.

[0014] According to a specific embodiment of the present invention, preferably, the anaerobic culture time is preferably 20-60 h, more preferably 40-50 h, and further preferably 48 h.

[0015] According to a specific embodiment of the present invention, preferably, the culture medium is blood agar medium.

[0016] According to a specific embodiment of the present invention, based on the total volume of the culture medium, the components of the culture medium include: Columbia blood agar base 40-50 g / L, sterile defibrinated sheep whole blood 45-55 mL / L, 55-65% sodium lactate 15-26 mL / L, preferably, the concentration of the sodium lactate is 60%.

[0017] According to a specific embodiment of the present invention, preferably, based on the total volume of the culture medium, the culture medium comprises: 44 g / L Columbia blood agar base, 50 mL / L sterile defibrinated sheep whole blood, and 21 mL / L 60% sodium lactate.

[0018] According to a specific embodiment of the present invention, based on the total volume of the culture medium, the culture medium further comprises 5-15 mL / L of 3-5% cysteine ​​to accelerate the growth rate of Veillonella enteritidis; preferably, the concentration of the cysteine ​​is 4%.

[0019] According to a specific embodiment of the present invention, preferably, based on the total volume of the culture medium, the culture medium further comprises 10 mL / L of 4% cysteine.

[0020] On the other hand, the present invention provides a use of the above-mentioned Veillonella enteritidis as a marker microorganism or target in the preparation of a drug for screening diseases caused by the Veillonella enteritidis.

[0021] According to a specific embodiment of the present invention, preferably, the disease comprises inflammatory bowel disease.

[0022] On the other hand, the present invention provides a use of a reagent for detecting the above-mentioned Veillonella enteritidis in the preparation of a detection agent for detecting a disease caused by the Veillonella enteritidis.

[0023] According to a specific embodiment of the present invention, preferably, the disease comprises inflammatory bowel disease.

[0024] The present invention provides a Veillonella enteritidis and an application thereof. Specifically, the Veillonella enteritidis is a new species within the genus Veillonella that is separated and identified from the feces of patients with inflammatory bowel disease. By analyzing its genomic characteristics and biological characteristics, it is found that compared with Veillonella parvula, the species shows specificity in biological characteristics and pathogenicity, which helps to further improve the understanding of intestinal Veillonella and provides a new perspective and new direction for the study of the role of Veillonella in intestinal diseases such as IBD, which is of great significance for revealing the mechanism of action of Veillonella in the occurrence and development of inflammatory bowel disease. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Colony morphology and transmission electron microscopy images of Veillonella enteritidis Ser01 (B and D) and Veillonella parvum Ser02 (C and E).

[0026] Figure 2 This is the evolutionary relationship diagram of Veillonella enteritidis Ser01 and Veillonella parvum Ser02 with other species.

[0027] Figure 3 This is the genome functional analysis map of Veillonella enteritidis Ser01 and Veillonella parvum Ser02.

[0028] Figure 4 These are the results of virulence gene analysis of Veillonella enteritidis Ser01 and Veillonella parvum Ser02.

[0029] Figure 5 A is a graph showing the growth characteristics of Veillonella enteritidis Ser01 and Veillonella parvum Ser02; A is a graph showing the relationship between the bacterial count of Veillonella and the absorbance OD600; and B is a graph showing the growth curve of the Veillonella isolate.

[0030] Figure 6 This is a graph showing the results of carbon source utilization analysis of Veillonella enteritidis Ser01 and Veillonella parvum Ser02.

[0031] Figure 7 A is the result of the catalase test of Veillonella enteritidis Ser01; B is the OD value after potassium nitrate and sodium lactate were added to the culture medium 48 hours later. 600 value.

[0032] Figure 8 This is the wax moth lethality test and survival curve of Veillonella enteritidis Ser01 and Veillonella parvula Ser02.

[0033] Fig. 9 This is a picture of HE staining of the small intestine and the results of pathological changes after gavage of Veillonella enteritidis Ser01 based on the mouse inflammatory bowel disease model.

[0034] Fig.10 This graph shows the changes in intestinal villus length and crypt depth after gavage with Veillonella enteritidis Ser01 based on the mouse inflammatory bowel disease model.

[0035] Deposit of biological material for patent procedures:

[0036] The present invention Veillonella enterica Ser01:

[0037] Deposit date: October 8, 2024;

[0038] Depository: Guangdong Microbiological Culture Collection Center (GDMCC);

[0039] Address of the depository: Institute of Microbiology, Guangdong Academy of Sciences, 5th Floor, Building 59, No. 100, Xianlie Middle Road, Guangzhou;

[0040] Deposit number: GDMCC No: 65234;

[0041] Classification name: Veillonella enteritidis Veillonella enterica ). DETAILED DESCRIPTION

[0042] To make the technical solutions and advantages of the present invention more clear, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments.

[0043] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are conventional biochemical reagents and can be obtained commercially unless otherwise specified.

[0044] In a specific embodiment of the present invention, the method for culturing Veillonella enteritidis comprises:

[0045] Veillonella enteritidis was inoculated into a culture medium, and the culture temperature was 37°C, the rotation speed was 180 rpm, and the culture medium was anaerobically cultured for 48 hours. Based on the total volume of the culture medium, the components of the culture medium included: Columbia blood agar base 44 g / L, sterile defibered sheep whole blood 50 mL / L, 60% sodium lactate 21 mL / L, and 10 mL / L of 4% cysteine.

[0046] In a specific embodiment of the present invention, each liter of OVSA culture medium contains 40 g of tryptic soy agar medium, 21 mL of sodium lactate, 50 mL of sheep blood, 16 mg of vancomycin hydrochloride and 1 mg of oxacillin sodium. After the basic culture medium components are sterilized and cooled to 50°C, sheep blood and antibiotics are added.

[0047] In a specific embodiment of the present invention, each liter of GLL medium contains 44 g Columbia agar, 50 mL sheep blood and 21 mL 60% sodium lactate.

[0048] In a specific embodiment of the present invention, each liter of VL liquid culture medium contains 23.8 g of Veillonella medium base and 21 mL of 60% sodium lactate.

[0049] Example 1: Isolation, identification and preservation of Veillonella enteritidis

[0050] According to aseptic operation, the stool sample was diluted with sterile water in a gradient manner, and 100 μL of the dilution was applied to the OVSA medium. After culturing at 37°C for 48 h in an anaerobic tank (80% N2, 10% H2, and 10% CO2), the suspected colonies were preliminarily screened according to the colony characteristics of Veillonella. According to the number of suspected colonies, corresponding 1.5 mL centrifuge tubes were prepared, and the centrifuge tubes were numbered in sequence. 50 μL of sterile water was added to the centrifuge tubes in advance. The suspected single colony was picked up in the centrifuge tube using an inoculation loop, mixed thoroughly, and an appropriate amount of bacterial solution was dipped into three lines on the GLL medium for preliminary separation and purification. Figure 1 As shown in A, the colonies of Veillonella in the culture medium are milky white in color, smooth in surface, round in shape, 2-4 mm in diameter, with complete edges and slightly dome-shaped, making them easy to distinguish. At the same time, add 50 μL of DNA-EZ Reagents V universal one-step DNA extraction solution to the remaining liquid in the centrifuge tube, place it in a constant temperature metal bath at 75°C and incubate it for 10 min to lyse the bacterial solution and fully release the DNA. Real-time quantitative PCR is then used to qualitatively detect Veillonella in suspicious colonies. PCR amplification was performed using the bacterial 16S rRNA gene, and the product was sent for DNA sequencing. The initially purified Veillonella was labeled according to the sequencing results and further isolated and purified on the newly prepared GLL culture medium ( Figure 1 B in Figure 1 C), and then the pure bacteria were frozen in a -80℃ ultra-low temperature refrigerator.

[0051] A single colony was picked and inoculated into VL liquid medium and cultured anaerobically at 37°C and 180 rpm for 48 h until OD 600 =1.2. Pipette 1 mL of bacterial solution, centrifuge at 8000 rpm for 5 min, and remove the supernatant. Add PBS buffer to the precipitate for washing, centrifuge at 8000 rpm for 5 min, and remove the supernatant again. Repeat the washing steps 3 times. Add 1 mL of electron microscopy fixative to the precipitate, mix it by blowing, and fix it at 4°C overnight. Wash it again with PBS buffer to remove the fixative. After washing, blow and mix the bacteria in PBS buffer, and add an equal amount of 2% sodium phosphotungstate aqueous solution to obtain a bacterial suspension. Pipette the mixed bacterial suspension and drop it on the copper mesh. After 5 minutes, use filter paper to absorb the remaining liquid. After the sample is dry, place it under a low-power optical microscope for examination. Select the copper mesh with intact membrane and uniform bacterial distribution. Observe it under a transmission electron microscope. The individual isolates are spherical with a diameter of about 0.3-0.5 μm, without flagella, capsules, or spores ( Figure 1 D in Figure 1 E in.

[0052] The Veillonella enteritidis Ser01 of the present invention has been deposited in the Guangdong Provincial Microbiological Culture Collection Center (address: Building 59, No. 100, Xianlie Middle Road, Yuexiu District, Guangzhou, Institute of Microbiology, Guangdong Academy of Sciences) on October 8, 2024, with a preservation date of October 8, 2024, and a classification name of Veillonella enteritidis, with a preservation number of GDMCC No: 65234. In the present invention, the bacterium is also referred to as Veillonella enteritidis Ser01.

[0053] Example 2: Genome evolutionary characteristics and functional analysis of Veillonella enteritidis isolates

[0054] Take the well-growing Veillonella bacterial liquid, use the kit to extract the genomic DNA of the Veillonella isolate and perform whole genome sequencing. The genome assembly quality assessment showed that the genome size of the Veillonella isolate was about 2Mb, and the median sequence length after genome assembly was N 50 >300 kb, G+C content of 38.5%, good assembly quality. 53 genomes were annotated using PubMLST rps The results showed that the newly isolated Veillonella enteritidis Ser01 did not completely match the database information, and a considerable part of rps The genes are different from those reported for Veillonella middle-zellensis, and are between Veillonella middle-zellensis ( Veillonella nakazawae ) and Veillonella dispar ( Veillonella dispar ) (Table 1). Based on the 16S rRNA gene, the phylogenetic tree of Veillonella enteritidis Ser01 and other Veillonella species was constructed, with yellow marks indicating isolates ( Figure 2 ), further indicating that Veillonella enteritidis Ser01 is a potential new species of Veillonella.

[0055] RAST was used to annotate the gene functions of the Veillonella enteritidis isolate. The annotation results showed that the gene functions of the Veillonella enteritidis isolate were mainly concentrated in nucleosides and nucleotide metabolism (Nucleosides and Nucleotides), virulence and disease (Virulence, Disease and Defense), membrane transport (Membrane Transport), carbohydrate metabolism (Carbohydrates), amino acids and derivatives metabolism (Amino Acids and Derivatives), DNA metabolism (DNA Metabolism), protein metabolism (Protein Metabolism), cofactors and vitamins metabolism (Cofactors, Vitamins, Prosthetic Groups, Pigments) and other aspects ( Figure 3 , Figure 4 ).

[0056]

[0057] Example 3. Growth curve and biological characteristics analysis of Veillonella enteritidis isolates

[0058] The size of individual bacteria of Veillonella is close, and the absorbance OD can be calculated by gradient dilution and coating counting. 600 The relationship between the amount of bacteria and the amount of bacteria was tested. The results showed that when the amount of Veillonella was 10 9 CFU / mL, the corresponding absorbance OD 600 is 1.2 ( Figure 5 The growth curves of the Veillonella isolates showed that the growth rate of Veillonella enteritidis Ser01 was slightly faster than that of Veillonella parvum Ser02, reaching the stable phase after 40 h of culture, while Veillonella parvum grew more slowly and reached the stable phase after about 48 h ( Figure 5 B). Absorbance OD 600 When the concentration of Veillonella reaches 10 9 CFU / mL, and it is in the logarithmic growth phase, which is suitable for subsequent experiments at this concentration.

[0059] In order to observe the ability of Veillonella to utilize carbon sources, the isolates were incubated in the Biolog instrument for 48 h, and a total of 28 substances in the AN identification plate showed color changes ( Figure 6 ). Among them, 23 substances of Veillonella parvum Ser02 had significant color changes (change values ​​greater than 10), and 28 substances of Veillonella enteritidis Ser01 had significant color changes (change values ​​greater than 10), which indicates that the new species of Veillonella enteritidis has a wider carbon source utilization spectrum than Veillonella parvum. Both Veillonella isolates can utilize common monosaccharides such as fructose, galactose and glucose, as well as glycolysis intermediates such as 1-phosphate glucose, 6-phosphate glucose, 3-methyl glucose and pyruvate, and can also utilize tricarboxylic acid cycle intermediates such as malic acid and fumaric acid, as well as lactic acid, the most important carbon source of Veillonella. The above results show that Veillonella enteritidis isolated from the intestines of patients with inflammatory bowel disease has the ability to utilize multiple carbon sources, and the carbon source utilization spectrum covers common monosaccharides, glycolysis intermediates and tricarboxylic acid cycle intermediates, which may be potentially related to its increased abundance during the development of the disease. The catalase test of Veillonella enteritidis Ser01 was positive ( Figure 7 A in the medium). Adding potassium nitrate to the culture medium can promote the growth of Veillonella enteritidis. Figure 7As shown in B, V represents the basic medium of Veillonella enteritidis, VK represents the above medium supplemented with 40 mM potassium nitrate, VL represents the above medium supplemented with 2.1% sodium lactate, and VKL represents the above medium supplemented with 40 mM potassium nitrate and 2.1% sodium lactate. The above results are consistent with the VFDB virulence gene annotation results that the Veillonella enteritidis isolate contains catalase and nitrate reductase.

[0060] Example 4: Analysis of virulence genes and pathogenicity of isolated strains of Veillonella enteritidis

[0061] VFDB was used to annotate Veillonella enteritidis isolates, and a total of 19 annotation results were obtained. These annotation results can be clustered into 10 virulence factors (Table 2). Lipo-oligosaccharides (LOS) and lipopolysaccharides (LPS) are collectively referred to as endotoxins, which are important components of the cell wall of Gram-negative bacteria and can cause host inflammatory responses. Molecular chaperones (GroEL) can help bacteria cope with high-temperature and dry environments. Streptococcal enolase can bind to a variety of human proteins to help bacteria escape immune evasion. Hemolysin can promote host cell membrane dissolution and lead to cell apoptosis. Nitrate reductase can help anaerobic bacteria in anaerobic respiration and counteract the reactive nitrogen produced by the host. Iron uptake is an important way for bacteria and hosts to compete for iron ions. Nucleoside diphosphate kinase is related to bacterial adhesion and biofilm formation. Catalase can help bacteria fight reactive oxygen.

[0062]

[0063] 1.0×10 9 CFU / mL Veillonella was injected into the body cavity of the larvae through the right hind leg of the wax moth with a microsyringe at a rate of 10 μL. Ten wax moths were injected in each group, and the PBS group was used as the control. Each group of wax moths was placed in a disposable culture dish and incubated at 37°C. The survival of wax moths in each group was recorded every 3 h. The experimental results showed that after the injection of Veillonella enteritidis Ser01 and Veillonella parvum Ser02, the survival curves of the two groups of wax moths changed similarly. The virulence of Veillonella enteritidis Ser01 was slightly stronger than that of Veillonella parvum Ser02 ( Figure 8 ).

[0064] In the mouse inflammatory bowel disease model, four parallel groups of mice were set up, with 5 mice in each group, namely the normal drinking water control group (PBS+H2O group), the Veillonella enteritidis Ser01 gavage group (Vei+H2O group), the inflammatory bowel disease control group (PBS+DSS group) and the inflammatory bowel disease plus Veillonella enteritidis Ser01 gavage group (Vei+DSS group). The corresponding drinking water was added to each group of mice from the 0th day of the experiment, and it was changed every 2 days. The Vei+H2O group and the Vei+DSS group were treated with Veillonella enteritidis Ser01 by gavage on the 2nd, 4th and 6th days, and the other two groups of mice were used as controls. The same gavage treatment with PBS was performed to embed the intestinal tissue of mice, and the sections and HE staining were performed. The results showed that the intestinal tissue structure of the PBS+H2O group was basically normal; the intestinal structure of the Vei+H2O group was slightly abnormal, with some crypts moving up and twisting; the intestinal tissue structure of the PBS+DSS group was slightly abnormal, with some crypts twisting and crypt branches; the intestinal tissue structure of the Vei+DSS group was moderate to severe abnormal, with a significant decrease in the number of crypts in the field of view, and some remaining crypts twisted; the intestinal villus structure was disordered, some mucosal epithelial cells eroded and fell off, the propria was exposed, and a large number of shed cell fragments could be seen in the intestinal cavity ( Fig. 9 The length of small intestinal villi and crypt depth of mice in each group were tested, and it was found that the length of villi in the Vei+DSS group was significantly shortened, and the depth of crypts was significantly reduced ( Fig.10 ). This indicates that the addition of Veillonella enteritidis Ser01 had a significant impact on the small intestine of mice and destroyed the structure of the small intestine of mice. This phenomenon was more obvious in the inflammatory bowel disease model.

[0065] Veillonella enteritidis Ser01 in the present invention is a new species of Veillonella isolated and identified from the feces of patients with inflammatory bowel disease. First, through 16S rRNA sequence analysis, it was found that the strain had a high similarity with Veillonella nadzematica (99.58%). However, based on more rpsComparison of genes (53 species) and whole genome ANI revealed that the bacteria had significant genetic differences from other species in the existing genus Veillonella, reaching the standard for classification of new species (ANI < 95%). Second, this isolate of Veillonella enteritidis has the ability to utilize multiple carbon sources, and the carbon source utilization spectrum covers common monosaccharides, glycolysis intermediates and tricarboxylic acid cycle intermediates. It can also express molecular chaperones GroEL, catalase and nitrate reductase. These biological characteristics may be potentially related to the increased abundance of Veillonella during the development of the disease. Third, in the annotations of the VFDB and RAST databases, the newly isolated Veillonella enteritidis Ser01 has similar gene functions and virulence genes to those of Veillonella parvula. However, in the greater wax moth model, the virulence of the newly isolated Veillonella enteritidis Ser01 was slightly stronger than that of Veillonella parvula; moreover, in the mouse inflammatory bowel disease animal model, intestinal colonization of the newly isolated Veillonella enteritidis Ser01 significantly aggravated the lesions of the intestinal tissue of IBD mice.

[0066] In summary, the present invention successfully isolated and identified a new Veillonella from the feces of patients with inflammatory bowel disease, named Veillonella enteritidis Ser01, which has significant genetic differences from other species in the existing genus Veillonella and has reached the standard for classification of new species. The present invention analyzed the virulence genes and pathogenicity of Veillonella enteritidis Ser01, and the analysis results showed that Veillonella enteritidis Ser01 has the potential pathogenicity to aggravate inflammatory bowel disease. It is worth mentioning that compared with Veillonella parvum, this species shows specificity in biological characteristics and pathogenicity, which has improved the understanding of the genus Veillonella in the intestine and provided a new perspective and direction for the study of the role of Veillonella in intestinal diseases such as IBD.

Claims

1. A Veillonella enteritidis Veillonella enterica ), characterized in that, The deposit number of the Veillonella enteritidis is GDMCC No: 65234.

2. A Veillonella enteritidis preparation, characterized in that: The Veillonella enteritidis preparation contains Veillonella enteritidis with a preservation number of GDMCC No: 65234.

3. The Veillonella enteritidis preparation according to claim 2, characterized in that: The Veillonella enteritidis preparation is an inactivated preparation or a live bacteria preparation.

4. The Veillonella enteritidis preparation according to claim 2, characterized in that: The Veillonella enteritidis preparation is a liquid preparation or a solid preparation.

5. A method for culturing Veillonella enteritidis according to claim 1, characterized in that: The method comprises: Veillonella enteritidis was inoculated into the culture medium at a culture temperature of 36-38°C and cultured anaerobicly.

6. The culture method according to claim 5, characterized in that: The culture medium is blood agar culture medium.

7. Use of the Veillonella enteritidis described in claim 1 as a marker microorganism or target in the preparation of a drug for screening diseases caused by the Veillonella enteritidis.

8. The use according to claim 7, characterized in that: Such diseases include inflammatory bowel disease.

9. Use of the reagent for detecting Veillonella enteritidis according to claim 1 in preparing a detection agent for detecting diseases caused by Veillonella enteritidis.

10. The use according to claim 9, characterized in that: Such diseases include inflammatory bowel disease.

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