Animal model for mechanical injury of intestinal tract, experimental device and application of animal model

Abstract

The invention provides an intestinal mechanical injury animal model. The model is inserted into the intestinal tract of an experimental animal through a modeling experimental device for staying or friction modeling; and collecting experimental animal intestinal samples for evaluating the mechanical injury of the intestinal tract. The invention further provides an intestinal tract mechanical injury experimental device which comprises an intestinal tract brush, and the intestinal tract brush comprises a brush head, a brush head protective cover and a brush head handle; the tail part of the brush head is connected with the brush head handle, different bristles are arranged at the head part of the brush head, the brush head protective cover covers part of the surface area of the brush head, and the brush head protective cover controls the covered bristle part through movement. According to the brush head protective cover, the covered brush hair part is controlled through relative rotation of the brush head protective cover and the brush head, the brush hairs with different rigidities or lengths are correspondingly exposed for a modeling experiment, and control over different degrees of mechanical damage is achieved. The technical problems that in the prior art, modeling operation is complex, the mechanical damage degree is low, and the damage degree cannot be controlled are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of model construction and verification, and specifically relates to an intestinal mechanical injury animal model, an experimental device and uses thereof. Background Art

[0002] Establishing an animal model of intestinal mechanical injury is an important tool for studying intestinal injury repair mechanisms, evaluating drug efficacy, and pathophysiology. Causes of intestinal mechanical injury include foreign body stimulation, chronic constipation, and damage caused by colonoscopy.

[0003] "Prevention and Countermeasures of Gynecological Laparoscopic Intestinal Injury" (Chinese Journal of Minimally Invasive Surgery, 2008, 03:201-204) points out that intestinal injury is a rare but serious complication of gynecological laparoscopic surgery. Causes of intestinal injury include previous abdominal surgery, pelvic and abdominal adhesions, and gastrointestinal flatulence. Mechanical intestinal injury primarily occurs in patients with severe pelvic and abdominal adhesions caused by a history of abdominal surgery or severe endometriosis, resulting in intestinal damage during puncture or adhesion separation. Intestinal injury can occur in the small intestine, sigmoid colon, and rectum. Intestinal injury can be diagnosed both intraoperatively and postoperatively. However, only 50% of intestinal injuries are detected intraoperatively. Approximately half of intestinal injuries are diagnosed only after symptoms of varying severity develop postoperatively, and this condition is often underreported. In cases of postoperative mechanical intestinal injury, treatment is often sought through secondary laparoscopic exploration, surgical repair or anastomosis, and transverse colostomy, which prolongs the patient's prognosis and may even cause secondary injury.

[0004] Mechanical damage to the intestine is also a common cause of mechanical intestinal obstruction. For example, postoperative adhesions account for 60% to 75% of the causes of mechanical intestinal obstruction. Scar tissue formation after intestinal damage may lead to intestinal stenosis, which may develop into intestinal obstruction. Intestinal wall edema after trauma, intra-abdominal bleeding or foreign bodies may directly compress the intestine or become embedded in the intestinal cavity, causing blockage. Moreover, mechanical intestinal obstruction can lead to secondary intestinal damage, such as ischemic necrosis of the intestinal wall after intestinal obstruction. Intestinal dilatation can destroy the intestinal wall muscle layer and ganglion cells, aggravating the obstruction. Abdominal surgery and postoperative complications used in the treatment of mechanical intestinal obstruction can also cause or aggravate intestinal wall damage. When screening drugs for treating intestinal mechanical damage, it is necessary to establish an efficacy model. The prior art discloses methods for screening drugs for treating intestinal mechanical damage diseases using clinical trials and animal models.

[0005] CN117018045A "Application of Lactobacillus rhamnosus in the preparation of drugs for alleviating mechanical damage" (publication date: 2023.11.10) discloses the use of Lactobacillus rhamnosus R7970 in the preparation of drugs for alleviating mechanical damage. In the experimental design, patients who underwent colonoscopy and small enteroscopy at the endoscopic diagnosis and treatment center of a hospital were randomly selected. After completing the colonoscopy, feedback statistics on adverse reactions caused by mechanical damage were performed. Among them, adverse reactions include abdominal distension, abdominal pain, diarrhea, loss of appetite, indigestion and bloody stools. This clinical trial requires informed consent and ethical review, and the experimental cost is high and time-consuming.

[0006] "Preparation of a Reducible Mechanical Complete Intestinal Obstruction Model" (Chinese Journal of Experimental Surgery, 2009, 26(4): 525-526) A Foley catheter is surgically inserted into the colon mesentery to apply pressure (as in the rabbit model) to simulate mucosal ischemia or structural damage caused by local mechanical compression. A surgical incision of approximately 5 cm is made on the right side of the abdomen of a large-eared white rabbit. The small intestine is gently advanced to locate the enlarged round sac at the end of the cecum. Two concentric purse-string sutures are made on the mesenteric wall of the round sac with non-absorbable sutures, 1 cm apart. A small incision of approximately 0.5 cm in diameter is made in the center of the purse-string suture. A Foley catheter is inserted approximately 8 to 10 cm into the proximal ileum. The two concentric purse-string sutures made on the mesenteric wall are ligated to invert the intestinal wall. The catheter is drawn out from the incision, and the incision is closed with interrupted sutures. During the operation, 5% levofloxacin glucose solution was instilled into the peritoneal cavity (60 drops / min). After the operation, the animals were returned to the cage and fed normally for 3 days after awakening from anesthesia. On the 3rd day after the operation, 5 mL of normal saline was injected into the catheter balloon to cause complete intestinal obstruction.

[0007] CN118924477A "Evaluation Method for Intestinal Anastomotic Stents" (published on November 12, 2024) established a rabbit model of mechanical intestinal obstruction: After anesthesia, the rabbit underwent laparotomy and a soft rubber tube was placed in the non-vascular area of the mesentery 5 cm distal to the anus to form a uniform loop obstruction. The rabbits were subjected to obstruction for different durations (6 hours, 12 hours, 18 hours, 24 hours, 30 hours, and 36 hours). Surgical intestinal mechanical injury modeling requires high experimental operation requirements and is relatively cumbersome.

[0008] The prior art also discloses non-surgical intestinal mechanical injury models, but the modeling effect is not significant.

[0009] CN111602630A, "Method for Establishing a Model of Mechanical Injury to the Small Intestine of Broiler Chickens Induced by Deoxynivalenol" (published on September 1, 2020), uses a complete feed containing 10 mg / kg of deoxynivalenol to feed one-day-old broilers for 7 days to establish a model of mechanical injury to the small intestine caused by deoxynivalenol. This experimental design cannot replicate the effects of mechanical force on the body, causing structural damage and / or functional impairment.

[0010] CN114796286A "Application of Phascolarctobacterium in the Preparation of Intestinal Repair Preparations" (publication date: 2022.07.29) humanized mice to more realistically simulate the human intestinal conditions. The mice were first transplanted with intestinal flora from people who recovered slowly after clinical colonoscopy. On this basis, they underwent intestinal cleansing treatment in clinical colonoscopy. At the same time, DSS was used to induce enteritis in mice to simulate intestinal traumatic damage (i.e., intestinal mechanical damage) caused by colonoscopy. The experimental design requires the isolation of intestinal strains and then transplantation into healthy mice, which takes a long time to operate; the use of DSS to induce enteritis in mice also weakens the contribution of intestinal mechanical damage itself in the animal model.

[0011] The study "Effects of Changkang Recipe on Visceral Hypersensitivity in Rats with Irritable Bowel Syndrome" (Chinese Journal of Integrated Traditional and Western Medicine in Digestion, 2012, 20(1):15-18) simulated intestinal obstruction. Rats were fasted for 12 hours and placed in a self-made transparent glass cage. The rats could only move forward and backward in the cage and could not turn around. After the rats adapted, a balloon was inserted through the anus, inserted 6 to 8 cm, and the catheter was tied to the rat's tail with tape to fix the balloon. Air was injected into the balloon based on different pressure stimulations. The rats' enriched contraction reflex to rectal balloon distension was observed at pressures of 10, 20, 40, 60, and 80 mmHg. Each rectal distension lasted 20 seconds. The rats' responses to rectal distension induced by different pressures were also observed, and semi-quantitative behavioral scores were recorded based on their responses. This modeling method does not require abdominal surgery, but the degree of mechanical damage caused by balloon inflation is relatively low, making it more suitable for simulating visceral sensitivity in irritable bowel syndrome. Summary of the Invention

[0012] The present invention provides an animal model of intestinal mechanical injury, which is used to solve the problems in the prior art of complex modeling operations, low degree of mechanical injury and inability to control the degree of injury. The present invention inserts a modeling experimental device into the intestine of an experimental animal to stay or rub to form a model; and collects intestinal samples of the experimental animal for intestinal mechanical injury assessment. The animal model provided by the present invention is simple to model and more suitable for promotion; the intestinal mechanical injury experimental device can adjust the injury site and degree of injury. In addition, the modeling results are also verified by pathological tissue, intestinal flora, related gene expression levels, etc., with a high modeling success rate and the ability to determine the level of injury.

[0013] The present invention also provides an intestinal mechanical injury experimental device, which integrates a brush head, a brush head protective cover, and a brush head handle. The brush head protective cover covers a portion of the brush head surface area. The brush head protective cover controls the covered bristles by rotating relative to the brush head, correspondingly exposing bristles of different stiffness and / or length, thereby achieving control of different degrees of mechanical injury. The experimental device provided by the present invention can also be used for modeling without surgery, eliminating the need for a lubricant delivery device, and simultaneously controlling the size of the modeling wound and the location of the intestine, effectively reducing the difficulty of modeling.

[0014] The technical solutions provided by the present invention are as follows:

[0015] An animal model of intestinal mechanical injury, which is inserted into the intestine of an experimental animal through a modeling experimental device to stay or rub in the intestine to create a model, and intestinal samples of the experimental animal are collected for intestinal mechanical injury evaluation. The evaluation indicators include: the degree of colon mucosal edema, the expression level of intestinal barrier-related genes, and the relative abundance of intestinal flora; the modeling experimental device includes a brush or an intestinal mechanical injury experimental device with a brush head structure.

[0016] Preferably, the degree of colonic mucosal edema includes an increase in the thickness of the colonic submucosa.

[0017] Preferably, the expression levels of intestinal barrier-related genes are reduced, and the related genes include the key genes for mucus secretion in the colon, MUC1, MUC2, MUC3, and the tight junction protein gene Occludin.

[0018] Preferably, the intestinal flora includes Bacteroidota and Firmicutes, wherein the relative abundance of Bacteroidota decreases; and the relative abundance of Firmicutes increases.

[0019] Preferably, the intestinal mechanical injury animal model is divided into injury degrees by evaluation indicators, wherein the indicators include one or more of the degree of colon mucosal edema, the expression level of intestinal barrier-related genes, and the relative abundance of intestinal flora.

[0020] The present invention also provides the use of an intestinal mechanical injury animal model, which can be used for pathogenesis research, pathological characteristics research, related therapeutic drug screening, pharmacological research, drug efficacy evaluation and drug preparation.

[0021] The present invention also provides an intestinal mechanical damage experimental device, which includes an intestinal brush, which includes a brush head, a brush head protective cover and a brush head handle; the tail of the brush head is connected to the brush head handle, and different bristles are arranged on the head of the brush head, wherein the brush head protective cover covers part of the surface area of the brush head, and the brush head protective cover controls the covered bristle part by movement.

[0022] Furthermore, the brush head protective cover controls the covered bristle portion by rotating relative to the brush head.

[0023] Furthermore, the bristles have different bristle stiffness and / or bristle length, and the bristle stiffness has different bristle diameters, materials, bristle densities, and processing techniques.

[0024] Furthermore, the length of the bristles is X, the radius of the cross section of the brush head protective cover is R, the length of the ends of the brush head protective cover's cross section that are not covered by the bristles is F, and the distance between the brush head axis and F is D. The length of X satisfies the following condition: R>X>D.

[0025] Furthermore, the bristles are divided into mutually parallel functional areas, the edges of the functional areas are parallel to the edges of the brush head protective cover, and the bristles in the same functional area have the same length and stiffness.

[0026] In combination with the embodiment, the present invention provides a first possible implementation method, wherein an angle positioning groove is provided at the tail of the brush head protective cover, and an angle positioning groove corresponding to the buckle is provided at the brush head handle.

[0027] In combination with the embodiment, the present invention provides a second possible implementation method, the brush head handle and the brush head protective cover may also be provided with a rotating device, the rotating device connects the brush head handle and the brush head protective cover, and the rotating device is provided with internal and external threads.

[0028] Furthermore, an angle positioning line is set on the surface of the brush head handle, and a rotation angle scale line is set on the surface of the brush head protective cover.

[0029] Furthermore, a limiter is provided at the top of the brush head, and the limiter is made of a flexible material. Preferably, the flexible material includes one of silicone, thermoplastic elastomer, and soft rubber.

[0030] In combination with the above embodiment, the present invention provides a third possible implementation of the above embodiment, wherein the device further includes an intestinal brush protective cover, and the diameter of the intestinal brush protective cover is larger than the diameter of the intestinal brush.

[0031] Furthermore, the experimental device also includes a positioning device, the diameter of which is larger than the diameter of the intestinal brush protective sleeve.

[0032] Furthermore, a positioning groove is provided on the intestinal brush protective cover, and a buckle corresponding to the positioning groove is provided on the positioning device. Preferably, the brush head handle and / or the intestinal brush protective cover are provided with length scale lines.

[0033] The advantages of the present invention are:

[0034] 1. The intestinal mechanical injury animal model provided by the present invention solves the problems of complicated surgical modeling and poor modeling effect of non-surgical methods in the prior art.

[0035] The present invention uses an external experimental device modeling method plus evaluation indicators to complete the intestinal mechanical injury animal modeling. Compared with the existing surgical modeling method, the difficulty is reduced and the modeling effect is improved compared with the existing non-surgical modeling method. The present invention uses a brush or an intestinal mechanical injury experimental device containing a brush head structure to enter the animal's anus at a designated location in the intestine, and then stops or rubs to create a model. The experimental animal's intestinal samples are collected for damage assessment, including evaluation of the degree of colon mucosal edema, the expression level of intestinal barrier-related genes, the relative abundance of intestinal flora, etc., to determine whether the modeling is successful.

[0036] Among them, the degree of colonic mucosal edema includes increased thickness of the colonic submucosa;

[0037] Intestinal barrier genes include MUC1, MUC2, and MUC3, key genes for mucus secretion in the colon, and the tight junction protein gene Occludin, with reduced expression levels of the above genes;

[0038] The intestinal microbiota consists of the phyla Firmicutes and Bacteroidota. The relative abundance of Firmicutes increased, while that of Bacteroidota decreased. Firmicutes and Bacteroidetes are the primary phyla of the intestinal microbiota, and changes in the ratio of Firmicutes to Bacteroidetes (F / B) are generally considered a marker of altered intestinal microbiota structure. Results showed that after successful intestinal mechanical injury modeling, the F / B ratio of the rat intestinal microbiota increased.

[0039] At the same time, the present invention can also use one or more of the above indicators as a grading standard for the degree of damage: when several evaluation indicators are met at the same time, or when one or several evaluation indicators reach a certain value, different levels of damage are set, and then corresponding to the time the experimental device stays or rubs the model, the length and stiffness of the bristles, a modeling method for different degrees of damage is established.

[0040] The causes of conventional intestinal mechanical damage include foreign body stimulation, long-term constipation, and damage caused by colonoscopy. In the clinical process, due to different causes of damage and different injury times between different cases, it is difficult to achieve uniformity in the degree of damage and develop symptomatic drugs for different degrees of damage. The reproducibility of mechanical damage, the extent of damage, and the avoidance of intestinal perforation are the biggest difficulties in the modeling process. The inventors selected a brush as a modeling device from a variety of methods such as oral plastic microspheres, external barbed anal tubes, screws, tweezers, weighing spoons, and steel needles. The modeling effect of the present invention is good, the repeatability is high, and the degree of damage can be controlled by the length and stiffness of the bristles. The appropriate brush diameter can also be selected according to the intestinal diameter of the experimental animal, which better solves the problem of uniformity in the degree of damage.

[0041] 2. The experimental device provided by the present invention can better realize and control the different degrees of intestinal mechanical damage, and improve the success rate of modeling of different degrees of mechanical damage after combining with evaluation indicators.

[0042] The experimental device provided by the present invention establishes bristle functional areas of different lengths and stiffnesses, corresponding to different degrees of mechanical damage. During the modeling process, the covered bristle functional area is controlled by the relative rotation of the brush head protective cover and the brush head, and the uncovered bristle functional area is in direct contact with the intestine, causing different degrees of mechanical damage through friction. In order to ensure that bristles of different lengths can directly contact the intestine, the present invention also stipulates that the length of the bristles must meet the following conditions: R>X>D, where the bristle length is X, the cross-sectional radius of the brush head protective cover is R, the length of both ends of the uncovered bristle part in the cross-sectional area of the brush head protective cover is F, and the distance between the brush head axis and F is D.

[0043] In order to achieve the relative rotation of the brush head protective cover and the brush head, the present invention provides two optional solutions. Solution 1 uses the brush head protective cover and the brush head handle to set an angle positioning device. By rotating the brush head handle, when the brush head protective cover rotates to the position corresponding to the bristle functional area, the angle positioning groove at the tail of the brush head protective cover coincides with the angle positioning groove corresponding to the brush head handle, thereby determining the rotation angle of the brush head protective cover and the corresponding exposed bristle functional area, thereby controlling the degree of mechanical damage. Solution 2 uses the outside of the brush head handle and the inside of the brush head protective cover to set internal and external threads respectively. When the brush head handle rotates, the internal and external thread devices determine the rotation angle and fix the position after rotation, thereby determining the rotation angle of the brush head protective cover and the corresponding exposed bristle functional area, thereby controlling the degree of mechanical damage.

[0044] The brush head handle is set with an angle positioning line, and the tail of the brush head protective cover is set with a rotation angle scale line. Different functional areas correspond to different angles, so the functional area can be selected accordingly.

[0045] 3. The experimental device provided by the present invention can control the area of mechanical injury wound and the location of damaged intestine, reducing the risk of intestinal perforation.

[0046] The present invention provides a positioning piece made of a flexible material at the top of the brush head to prevent the device from entering the intestine and causing intestinal perforation due to the hard brush head material or excessive friction during the modeling process. A length scale line is provided in the middle of the brush head handle to control the position of entry into the intestine and the friction distance of the brush head, thereby determining the position of the damaged intestine and the area of the wound. When designing the bristle functional area, you can choose to leave a blank area, that is, a functional area where the bristle length is less than D or there is no bristle. When the brush head protective cover of the experimental device covers the entire bristle functional area and the blank area is exposed, the experimenter will not cause the bristles to rub against the intestinal wall when placing the device into the intestine; after reaching the specified position of the intestine, the bristle functional area is switched by rotating the brush head handle, thereby controlling the position of the intestinal damage.

[0047] 4. When the bristle functional area does not have a blank area, the present invention also uses an intestinal brush protective cover to control the wound size and intestinal position.

[0048] When the brush head of the experimental device is not provided with a blank area, the exposed bristle functional area will rub against the intestinal wall when the device enters the intestine, and the damaged part of the intestine cannot be controlled. The present invention adopts an intestinal brush protective cover to cover the brush head and the brush head protective cover. When the bristle functional area covers the entire brush head, the wound size and the position of the intestine can be controlled. During the experiment, the intestinal brush protective cover, the brush head and the brush head protective cover enter the intestine together; a length scale line is provided on the outside of the intestinal brush protective cover to calculate the position where the intestinal brush protective cover extends into the intestine; after the intestinal brush protective cover reaches the designated part of the intestine, the intestinal brush adjusts the position of the bristle functional area and then extends into the intestine through the intestinal brush protective cover. After reaching the designated position, the intestinal brush protective cover is pulled out to realize the friction modeling of the bristles on the intestinal wall.

[0049] To prevent the brush cover from falling off or overextending during insertion, a positioning device is installed on the brush cover. The brush cover is provided with a positioning slot, and the positioning device has a corresponding buckle. Adjusting the positioning slot and buckle positions the brush cover to determine where it enters the intestine, thereby controlling the location of mechanical incisions. The positioning device has a diameter larger than the intestinal opening. During operation, the experimenter only needs to push the experimental device into the intestine until the positioning device reaches the anus to prevent the brush cover from falling off or overextending. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be explained that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 Schematic diagram of the barbed anal canal.

[0052] Figure 2 A three-dimensional diagram of the experimental device 1 provided by the present invention.

[0053] Figure 3 A cross-sectional view of the experimental device 1 provided by the present invention.

[0054] Figure 4 Cross-sectional view of the experimental device 2 provided by the present invention.

[0055] Figure 5 Cross-sectional view of the experimental device 3 provided by the present invention.

[0056] Figure 6 Cross-sectional view of the experimental device 4 provided by the present invention.

[0057] Figure 7 The experimental device 4 provided by the present invention shows a top view of the brush head and the brush head protective cover, wherein the cross-sectional radius of the brush head protective cover is R, the length of both ends of the uncovered bristle portion of the cross-sectional area of the brush head protective cover is F, and the distance between the brush head axis and F is D.

[0058] Figure 8 A three-dimensional diagram of the experimental device 5 provided by the present invention.

[0059] Figure 9 Cross-sectional view of the experimental device 5 provided by the present invention.

[0060] Figure 10 A three-dimensional diagram of the experimental device 6 provided by the present invention.

[0061] Figure 11 Front view of the experimental device 7 provided by the present invention.

[0062] Figure 12 Front view of the experimental device 8 provided by the present invention.

[0063] Figure 13 Cross-sectional view of the experimental device 8 provided by the present invention.

[0064] Figure 14 Cross-sectional view of the experimental device 9 provided by the present invention.

[0065] Figure 15 Cross-sectional view of the intestinal brush protective sleeve and positioning device provided by the present invention.

[0066] Figure 16 Representative images of rat pathological sections and quantitative results. Figure 16 A is a representative image of rat colon H&E and AB-PAS staining (blue arrows point to the submucosa); Figure 16 Panel B shows the measurement results of submucosal thickness of rat colon by H&E staining (n=10, Mean±SEM); Figure 16 Panel C shows the percentage of mucus coverage area in rat colon AB-PAS staining (n=10, Mean±SEM) (Note: * indicates p<0.05 compared with the control group).

[0067] Figure 17 Results of RT-qPCR analysis of intestinal barrier-related genes in rat colon (n=8, Mean±SEM) (Note: * indicates p<0.05 compared with the control group). MUC1, MUC2, and MUC3 represent key mucus secretion genes in the colon; Occludin and Claudin1 represent genes for different tight junction proteins.

[0068] Figure 18 Results of rat serum DAO detection.

[0069] Figure 19 Analysis of fecal microbial diversity. Figure 19 A in the middle represents α diversity analysis; Figure 19 Middle B is β diversity analysis (control group: AC, model group: AM).

[0070] Figure 20 The fecal flora composition at the phylum level. AC1 to AC5 were the control group, and AM1 to AM5 were the model group.

[0071] Figure 21 The relative abundance of each bacterial phylum in the fecal microbiome is different. Firmicutes refers to the Firmicutes phylum; Bacteroidota refers to the Bacteroidetes phylum; F / B is the ratio of the relative abundance of Firmicutes to the relative abundance of Bacteroidetes; Actinobacteriota refers to the Actinobacteria phylum; Proteobacteria refers to the Proteobacteria phylum; Verrucomicrobiota refers to the Verrucomicrobia phylum; and Desulfobacterota refers to the Desulfovibrio phylum.

[0072] Reference numerals:

[0073] 1-brush head; 2-brush head protective cover; 3-brush head handle; 4-bristles; 5-functional area; 6-rotating device; 7-angle positioning groove; 8-angle positioning groove corresponding buckle; 9-angle positioning line; 10-rotation angle scale line; 11-limiting part; 12-intestinal brush protective cover; 13-positioning device; 14-positioning groove; 15-positioning groove corresponding buckle. DETAILED DESCRIPTION

[0074] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention generally shown and illustrated in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention. The experimental device provided by the present invention is generally used on experimental animals such as mice, rats, and rabbits. In view of the different experimental animals, damaged intestines and different diameters, the experimental device provided by the present invention is divided into multiple sizes.

[0075] Example 1: Screening of mouse modeling methods

[0076] 1. Experimental animals and experimental equipment

[0077] Fifteen male 10-week-old C57BL / 6J mice.

[0078] Anal tube with a diameter of 3.0 mm (Yangzhou Guilong Medical Instrument); stainless steel screw with a diameter of 2.5 mm; 10 cm ophthalmic forceps (Shanghai Jinzhong Medical Instrument, JD1050).

[0079] 2. Animal grouping and experimental methods

[0080] After three days of adaptive feeding, C57BL / 6J mice were divided into three groups according to their body weight, with 5 mice in each group, as shown in Table 1. After model establishment, sections were obtained and stained for analysis.

[0081] Table 1 Modeling methods for mouse groups

[0082]

[0083]

[0084] 3. Test results

[0085] All mice in the anal puncture group experienced bleeding after the procedure, and the anus was exposed to intestinal tissue. However, pathological sections showed no obvious damage. The anal puncture modeling method is easy to perform and provides consistent control; however, this method may result in intestinal damage that is not obvious and recovery is too rapid, leading to model failure.

[0086] Because the screw thread is sharp, the friction between the thread and the anus is large, the screw cannot be inserted, and the modeling fails.

[0087] After pinching with forceps, the intestines bleed, and pathological examination shows obvious damage in some areas. However, the degree of damage caused by this method is difficult to control, and a more consistent operation method should be found. The model failed.

[0088] Example 2: Screening of rat modeling methods

[0089] 1. Experimental animals, reagents, and experimental equipment

[0090] Eight male SD rats aged 7 weeks, weighing 200-250 g, were used. A weighing spoon (length 180 mm, handle width 3 mm), an inner hole brush (diameter 4 mm, manufactured by Anhui Qining), and paraffin oil (B500301, Shanghai Shenggong) were used.

[0091] 2. Animal grouping and experimental methods

[0092] After 3 days of adaptive feeding, SD rats were divided into 2 groups according to their body weight, with 4 rats in each group, as shown in Table 2.

[0093] Table 2 Modeling methods for rat groups

[0094]

[0095]

[0096] 3. Test results

[0097] Of the four rats in the weighing spoon stimulation group, one showed visible perforation, while the remaining rats showed no visible damage. Colon pathology revealed significant damage in three rats. While this modeling method can cause intestinal damage, it cannot replicate the severity of the injury.

[0098] Of the four rats in the brush stimulation group, one showed no obvious injury, two had extensive inflammatory infiltrates, and one had multiple hemorrhages and multiple small inflammatory infiltrates. Three days of continuous colonic stimulation with a brush can induce significant colonic inflammatory infiltrates. This method is simple to operate, highly consistent, and can produce significant colonic injury with a success rate exceeding 80%.

[0099] Example 3: Structure of experimental devices 1 to 4

[0100] In order to adapt to the intestinal diameters of different experimental animals and reduce the influence of paraffin oil on the intestinal modeling results, the present invention provides an experimental device that can complete modeling of different damage degrees without using paraffin oil.

[0101] Experimental setup 1, such as Figure 2 As shown, the device includes an intestinal brush, which includes a brush head (1), a brush head protective cover (2) and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and different bristles (4) are set on the head of the brush head, wherein the brush head protective cover covers part of the brush head surface area, and the brush head protective cover controls the covered bristle part by movement. The bristles have different bristle stiffness or bristle length, and the bristle stiffness has different bristle diameters, materials, bristle densities, and processing technologies. According to the different stiffness requirements of the bristles, the bristle materials can be nylon, silicone, steel wire, animal hair, etc.; the bristles can have a bristle diameter ranging from 0.1mm to 60mm; the bristle density can be of different categories such as extremely dense, dense, relatively dense, sparse, etc. The brush head protective cover switches the covered bristle part, and the uncovered bristles are used for modeling, thereby controlling the degree of mechanical damage to the intestine.

[0102] The brush head protective cover and the brush head are rotated relative to each other through a rotating device (6). The cross-sectional views of the experimental devices 1 to 4 show that the rotating device can include various types. Figure 3 、 Figure 5 In the experimental devices 1 and 3 shown, internal and external threads are provided at the tail of the brush head and the middle of the brush head protective cover; Figure 4 、 Figure 6In the experimental devices 2 and 4 shown, internal and external threads are provided in the middle of the brush head and the middle of the brush head protective cover. Figure 4 、 5 , 6. A limiter (11) is also provided at the top of the brush head. The limiter is made of a flexible material, including silicone, thermoplastic elastomer, soft rubber, etc.

[0103] Preferably, an angle positioning line (9) is provided on the surface of the brush head handle, and a rotation angle scale line (10) is provided on the surface of the brush head protective cover. Different bristle distribution positions are aligned with the angle scale lines, and the brush head handle is rotated to change the surface area of the brush head covered by the brush head protective cover, thereby better controlling the part of the modeling bristles that contacts the intestinal wall.

[0104] In view of the different experimental animals, damaged intestines and different tube diameters, the diameter of the brush head protective cover is greater than or equal to the inner diameter of the experimental animal's intestine, but cannot exceed 10% of the inner diameter of the animal's rectum.

[0105] In order to optimize the control of the degree of mechanical damage, the inventor divides the bristles into mutually parallel functional areas (5) according to the length and stiffness of the bristles. The edges of the functional areas are parallel to the edges of the brush head protective cover. Figure 7 As shown. To ensure that the bristles can rub against the intestinal wall, the bristle length is X, the cross-sectional radius of the brush head protective cover is R, the length at both ends of the uncovered bristle parts in the cross-sectional area of the brush head protective cover is F, the distance between the axis of the brush head and F is D, and the length of X satisfies the following conditions: R>X>D. The brush head protective cover controls the covered bristle functional area by relative rotation with the brush head, thereby switching the type of bristles used during the experiment, thereby controlling the degree of mechanical damage to the intestine. The bristle functional areas can be evenly distributed, or blank areas can be reserved, that is, functional areas where the bristle length is less than D or there are no bristles. The reserved blank area can protect the intestine when the device enters the intestine and control the modeling damage in different parts of the intestine rather than just in the rectum.

[0106] The usage process is as follows: After the experimental animal is anesthetized, first rotate the brush head protective cover of the intestinal mechanical injury experimental device to the blank area of the bristle functional area, and insert the experimental device into the intestine through the animal's anus. Determine the distance into the intestine according to the position of the intestine and the scale lines on the surface of the brush head protective cover; after arriving at the designated location, rotate the brush head handle so that the angle positioning line is turned to the position specified by the rotation angle scale line on the surface of the brush head protective cover, and the corresponding bristle functional area is separated from the brush head protective cover and directly contacts the intestinal wall; leave it still or rub the brush head handle together with the brush head protective cover back and forth and left and right to establish an animal model of intestinal mechanical injury.

[0107] Example 4: Experimental Device 5 Structure

[0108] An experimental device, such as Figure 8As shown, the device includes an intestinal brush, which includes a brush head (1), a brush head protective cover (2), and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and different bristles (4) are set on the head of the brush head, wherein the brush head protective cover covers part of the brush head surface area, and the brush head protective cover controls the covered bristle part by moving. The difference between experimental device 5 and device 1 is that experimental device 5 omits the rotating device (6), adds an angle positioning groove (7) at the tail of the brush head protective cover, and the brush head handle is provided with a buckle (8) corresponding to the angle positioning groove, as shown in FIG. Figure 9 shown.

[0109] Usage process: The experimental device 5 rotates the brush head handle (3). When the brush head protective cover rotates to the position corresponding to the bristle functional area, the brush head handle is pushed. The angle positioning groove (7) at the rear of the brush head protective cover coincides with the corresponding buckle (8) at the angle positioning groove at the bottom of the brush head handle. The rotation angle of the brush head protective cover and the corresponding exposed bristle functional area are determined. The experimental steps of Example 3 are then followed to establish an intestinal mechanical injury animal model.

[0110] Example 5: Experimental Device 6 Structure

[0111] An experimental device, such as Figure 10 As shown, the device includes an intestinal brush, which includes a brush head (1), a brush head protective cover (2), and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and different bristles (4) are arranged on the head of the brush head, wherein the brush head protective cover covers part of the brush head surface area, and the brush head protective cover controls the covered bristle part by moving.

[0112] The difference between Experimental Devices 5 and 6 is that the brush head guard of Experimental Device 5 covers a smaller area than that of Device 6. Experimental Device 5 has a longer brush head guard edge, but saves more material than Device 6. The use process of Experimental Device 6 is the same as that of Device 5.

[0113] Example 6: Experimental Device 7 Structure

[0114] An experimental device, such as Figure 11 The device comprises an intestinal brush and an intestinal brush protective cover (12), wherein the intestinal brush comprises a brush head (1), a brush head protective cover (2), and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and the head of the brush head is provided with different bristles (4), wherein the brush head protective cover covers a part of the brush head surface area, and the brush head protective cover controls the covered bristle part by moving. The diameter of the intestinal brush protective cover is larger than the diameter of the intestinal brush.

[0115] As described above, the inventors divided the bristles into mutually parallel functional areas (5) according to the length and stiffness of the bristles, and the edges of the functional areas are parallel to the edges of the brush head protective cover. When the bristle functional areas are evenly distributed and no blank areas are reserved, the rectum will be damaged by the exposed bristles when the intestinal brush enters the intestine, and it is impossible to control the damage to different parts of the intestine during modeling. The experimental device 7 is provided with an intestinal brush protective cover, and the diameter of the intestinal brush protective cover is larger than the intestinal brush. Preferably, a length scale line is provided on the intestinal protective cover to control the distance the intestinal protective cover enters the intestine.

[0116] Usage process: After the experimental animal is anesthetized, first rotate the brush head protective cover of the intestinal brush to the bristle functional area; insert the intestinal brush protective cover into the intestine through the animal's anus, and determine the distance of entry into the intestine according to the scale lines on the surface of the intestinal brush protective cover; insert the brush head into the animal's intestine through the intestinal brush protective cover, and determine the distance of entry into the intestine according to the scale lines on the surface of the brush head protective cover; after the brush head reaches the designated location, pull out the intestinal brush protective cover, and the corresponding bristle functional area is separated from the brush head protective cover and directly contacts the intestinal wall; leave it still or rub the brush head handle together with the brush head protective cover back and forth, left and right to establish an animal model of intestinal mechanical injury.

[0117] In view of the different experimental animals, damaged intestines and different diameters, the diameter of the intestinal brush protective sleeve is greater than or equal to the inner diameter of the experimental animal's intestine, but cannot exceed 10% of the inner diameter of the animal's rectum.

[0118] Example 7: Experimental Device 8 Structure

[0119] An experimental device, such as Figure 12 and 13 As shown, the device includes an intestinal brush, an intestinal brush protective cover (12) and a positioning device (13), wherein the intestinal brush includes a brush head (1), a brush head protective cover (2) and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and the head of the brush head is provided with different bristles (4), wherein the brush head protective cover covers a part of the brush head surface area, and the brush head protective cover controls the covered bristle part by movement. The diameter of the positioning device is larger than the diameter of the intestinal brush protective cover.

[0120] Preferably, a positioning groove (14) is provided on the intestinal brush protective sleeve, and a buckle (15) corresponding to the positioning groove is provided on the positioning device. The intestinal brush protective sleeve can be pre-determined with the positioning device to determine the position of the mechanical injury model, and the distance the intestinal brush protective sleeve extends into the intestine is fixed by the positioning groove on the intestinal brush protective sleeve and the buckle corresponding to the positioning groove provided on the positioning device. Preferably, the intestinal brush can be selected from the various types of embodiments 3 to 5.

[0121] Usage process: After the experimental animal is anesthetized, first rotate the brush head protective cover of the intestinal brush to the bristle functional area; determine the distance into the intestine according to the position of the intestine and the scale lines on the surface of the brush head protective cover, and fix the intestinal brush protective cover and the positioning device; insert the intestinal brush protective cover into the intestine through the animal's anus, and then insert the brush head and the brush head protective cover into the animal's intestine through the intestinal protective cover; after reaching the designated location, pull out the intestinal brush protective cover and the fixing device, and the brush head corresponding to the bristle functional area directly contacts the intestinal wall; leave it still or rub the brush head handle together with the brush head protective cover back and forth and left and right to establish an animal model of intestinal mechanical injury.

[0122] Example 8: Experimental Device 9 Structure

[0123] An experimental device, such as Figure 14 As shown, the device includes an intestinal brush, an intestinal brush protective cover (12) and a positioning device (13), wherein the intestinal brush includes a brush head (1), a brush head protective cover (2), and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and the head of the brush head is provided with different bristles (4), wherein the brush head protective cover covers a part of the brush head surface area, and the brush head protective cover controls the covered bristle part by movement. The diameter of the positioning device is larger than the diameter of the intestinal brush protective cover.

[0124] The difference between experimental device 8 and device 9 is that the intestinal brush used in experimental device 8 is experimental device 5, and the intestinal brush used in experimental device 9 is experimental device 1. Preferably, the intestinal brush can be selected from the various types of embodiments 3 to 5.

[0125] Example 9: Intestinal brush protective cover and positioning device structure

[0126] In order to optimize the fixing method of the intestinal brush protective sleeve and the positioning device, the positioning device adopts a wedge-shaped structure, a triangular prism, etc. as the corresponding buckle of the positioning slot. The buckle is a movable part and can be vertically extended and retracted under the action of external force; a positioning slot of the same shape is set on the intestinal brush protective sleeve, and the positioning slot is a fixed part. When the experimenter rotates the positioning device, the buckle is in a contracted state due to the external force of the intestinal brush protective sleeve wall; when it is rotated to the positioning slot of the same shape, the buckle returns to its original shape and is fixed to the positioning slot. Specifically, Figure 15 shown.

[0127] As an optimized technical solution, the intestinal brush protective cover can also be designed with an internal and external thread structure together with the positioning device, and the distance that the intestinal brush protective cover enters the intestine can be determined by the rotation of the positioning device.

[0128] Example 10: Modeling of the intestinal mechanical injury experimental device

[0129] 1. Experimental animals and reagents

[0130] 1.1 Experimental animals

[0131] Twenty healthy male SD rats, SPF grade, weighing 180-200 g were used. The rats were kept at room temperature (24±2)°C, relative humidity about 50%, and maintained under a 12-hour light / dark cycle.

[0132] 1.2 Reagents

[0133] 4% paraformaldehyde (Biosharp); rat LPS detection kit (Wuhan Huamei); rat DAO detection kit (Wuhan Huamei Biotechnology); rat IL-1β detection kit (Invitrogen); RNAiso Plus (Takara); cDNA reverse transcription kit (Tiangen Biochemical Technology Co., Ltd.); SYBRGREEN fluorescence quantitative kit (Tiangen Biochemical Technology Co., Ltd.); PCR plate (Roche); primers (Shanghai Bioengineering).

[0134] 2. Test methods

[0135] 2.1 Rats grouping

[0136] After one week of adaptive culture, the rats were randomly divided into a control group and a model group according to their body weight, with 10 rats in each group.

[0137] 2.2 Modeling method

[0138] Before modeling, the rats were grasped and gently massaged on the abdomen to encourage them to expel as much feces as possible from the posterior colon. After the rats were anesthetized with isoflurane, a 4 mm diameter intestinal brush was placed in an anal cannula device and slowly inserted through the rat's anus. After the device was inserted 7 cm, the brush handle was rotated to ensure that the bristles of the brush were in complete contact with the colonic mucosa. The device was placed in the rat's colon for 10 minutes, after which the rats were removed to terminate anesthesia. Rats were stimulated in this manner for 3 consecutive days, with samples collected on the 4th day.

[0139] 2.3 RNA extraction, reverse transcription, and RT-qPCR

[0140] An appropriate amount of rat colon tissue was collected for modeling. Two magnetic beads and 1000 μL of RNAiso Plus lysis buffer were added and homogenized in a cryo-grinding machine (4°C, 60 Hz, 90 s, repeated three times). The RNAiso Plus kit instructions were followed. The concentration and purity of the resulting RNA were determined using a microplate reader. 1 μg of RNA sample was reverse-transcribed into 20 μL of cDNA using the FastKing cDNA First-Strand Synthesis Kit. Fluorescence quantitative PCR was performed using the SuperReal PreMix Color (SYBR Green) color fluorescence quantitative premix kit to detect mucus secretion-related genes MUC1, MUC2, and MUC3, and intestinal barrier-related genes Claudin1 and Occludin. The total reaction volume was 10 μL, consisting of 5 μL of 2× SuperReal PreMix Plus, 0.8 μL of 10 μM forward and reverse primers, 1.4 μL of RNase-free water, and 2 μL of template (containing 20 ng of cDNA).

[0141] The reaction conditions were as follows: a first step of denaturation at 95°C for 15 minutes, followed by a second step of 95°C for 10 seconds and 60°C for 30 seconds, for a total of 40 cycles. The housekeeping gene β-actin was used as an endogenous reference for normalization. PCR data were calculated using the comparative threshold cycle (Ct) method using the formula 2-ΔCt. Gene expression was calculated by normalizing to the mean of the control group.

[0142] Table 3 RT-qPCR primer sequences

[0143]

[0144] 2.4 Determination of serum LPS, DAO, and IL-1β biochemical indicators

[0145] Take appropriate amount of serum and detect LPS, DAO and IL-1β in the serum according to the instructions provided by the manufacturer.

[0146] 2.5 Histological staining

[0147] The pathological changes of rat colon were examined by HE and AB-PAS staining. The specific procedures are as follows:

[0148] For HE staining, paraffin sections were placed in an oven at 60°C for 1-2 h; paraffin sections were dewaxed with conventional xylene and ethanol until water was obtained; hematoxylin staining was performed for 10 min, and the sections were rinsed with running water to remove residual color; 0.7% hydrochloric acid ethanol was differentiated for a few seconds, and the sections were rinsed with running water until they turned blue for 15 min; 95% ethanol was used for 30 seconds; alcohol eosin staining was performed for 30 seconds; gradient ethanol (95%→100%) was used for dehydration; xylene carbolate was used for 30 seconds; xylene was used for clearing; neutral gum was used for mounting; and the sections were scanned with a panoramic scanner.

[0149] For AB-PAS staining, sections were removed, treated with conventional xylene, and dewaxed with ethanol until water was available. Sections were immersed in alcian blue solution (pH 2.5) for 10–30 minutes and rinsed with distilled water. Sections were oxidized in 1% periodic acid solution for 5–10 minutes and rinsed with distilled water. Sections were placed in Schiff's reagent, reacted in the dark for 10–20 minutes, and rinsed with running water for 10 minutes. Sections were dehydrated with gradient ethanol (70% → 80% → 95% → 100%), cleared with xylene, mounted with neutral gum, and scanned with a panoramic scanner.

[0150] Statistical method for colon submucosal thickness: In the slice reading software, the submucosal thickness was measured at 5 locations in each slice.

[0151] Statistical method for the percentage of mucus coverage area: A complete colon cross-section was captured at a 4x field of view. The screenshot was converted to the "RGB Stack" format using Image J software. The "Red" pane was selected to quantify the area of oil-red mucus coverage (Threshold parameter 0-85) and the area of total cell coverage (Threshold parameter 0-200). The ratio of the two areas was the mucus coverage percentage.

[0152] 2.6 16S rRNA sequencing of intestinal flora

[0153] An appropriate amount of feces was added to the lysis buffer and grinding beads for grinding. Nucleic acid was extracted using the MagBeads FastDNA Kit for Soil (116564384) (MP Biomedicals, CA, USA). The highly variable V3V4 region of the bacterial 16S rRNA gene was selected for sequencing. PCR amplification was performed using primers specific for the bacterial 16S rRNA V3-V4 region: 338F (5'-barcode + ACTCCTACGGGAGGCAGCA-3') and 806R (5'-GGACTACHVGGGTWTCTAAT-3'). After the necessary PCR components were prepared, the template DNA was pre-denatured at 98°C for 5 minutes in a PCR instrument to fully denature the template DNA. Amplification cycles were then initiated. Each cycle began with a 30-second hold at 98°C to denature the template. The temperature was then lowered to 52°C for 30 seconds to allow for primer annealing. The primers were then extended at 72°C for 45 seconds to complete DNA synthesis, completing the cycle. Repeat this cycle 25 times to enrich the amplified DNA fragments. Finally, keep it at 72°C for 5 minutes to allow the product to be fully extended and store it at 12°C. The amplification results were subjected to 2% agarose gel electrophoresis, and the target fragments were cut out and then recovered using the Axygen gel recovery kit. The PCR products were quantified on a Microplate reader (BioTek, FLx800) using the Quant-iT PicoGreen dsDNA Assay Kit, and then mixed according to the data volume required for each sample. The library was constructed using Illumina's TruSeqNano DNALT Library Prep Kit. The library was quantified using Qubit4; and the PCR enriched fragments were quality controlled using Agilent 2100 to verify the fragment size and distribution of the DNA library. Normalize and mix the libraries: Multiple sample DNA libraries (multiplexed DNA libraries) were normalized to 10nM and then mixed in equal volumes. After diluting the mixed library (10 nM) to an appropriate concentration, paired-end sequencing (2 × 250 bp) was performed on an Illumina NovaSeq machine using the NovaSeq 6000 SP Reagent Kit (500 cycles). Microbiome biological information was analyzed using QIIME 22024.5, a modified and improved process based on the official tutorial (https: / / docs.qiime2.org / ).

[0154] 2.7 Statistical methods

[0155] GraphPadPrism 8.0 software was used for data analysis. Data were first tested for normal distribution using an unpaired t-test; otherwise, a nonparametric test was used. Results are presented as mean ± standard error (SEM). A p < 0.05 was considered statistically significant.

[0156] 3. Test results

[0157] 3.1 Histological test results

[0158] Pathological sections and quantitative results Figure 16 As shown in Figure 2. The submucosa of rat colon contains abundant blood vessels and lymphatic vessels, and its thickness can reflect the degree of colon inflammation. Figure 16 As shown in A and 16B, the thickness of the submucosal layer in the model group increased significantly, and obvious bleeding was observed in the submucosal layer and mucosa of some rats (e.g. Figure 16 Ad). However, the results of AB-PAS showed that the mucus coverage rate in the model group did not change significantly ( Figure 16 A, 16C).

[0159] 3.2 Brush stimulation changes the expression of genes related to the colonic intestinal barrier

[0160] Detection of rat intestinal barrier-related genes, such as Figure 17 As shown in the results, it was found that the mRNA levels of key mucus secretion genes MUC1, MUC2, MUC3 and tight junction protein Occludin in the colon showed a significant downward trend, indicating that brush stimulation would cause certain damage to the intestinal barrier. Although the three-day modeling had no effect on the mucus coverage, the decrease in MUC1, MUC2 and MUC3 indicated that increasing the modeling time would likely also affect mucus secretion.

[0161] 3.3 Brush stimulation did not affect whole blood serum DAO

[0162] like Figure 18 As shown, brushing stimulation did not affect serum DAO. Furthermore, serum LPS and IL-1β levels were below the detection limit of the assay. This suggests that brushing stimulation may only cause local damage to the colon without causing systemic effects.

[0163] 3.4 Brush stimulation changes the structure of fecal flora

[0164] The results of 16S rRNA sequencing of fecal flora showed that there were certain differences in α diversity between the control group and the model group; β diversity analysis showed that there were obvious differences in the flora structure between the control group (AC) and the model group (AM), such as Figure 19 The results showed that brush stimulation changed the diversity of fecal microbiota.

[0165] The bacterial community composition at the phylum level of each sample is as follows Figure 20 As shown in the figure, the Bacteroidota in the model group showed a downward trend, while the Firmicutes showed an upward trend. Bacteroidetes and Firmicutes are the main components of the intestinal flora, and changes in the ratio of the two (F / B) are generally considered to be a sign of changes in the structure of the intestinal flora. Figure 21 As shown in the figure, the relative abundance of each major bacterial phylum was analyzed. The results showed that the relative abundance of Bacteroidetes decreased significantly, the relative abundance of Firmicutes increased significantly, and the F / B ratio showed an upward trend. The relative abundance of Actinobacteriota, Proteobacteria, Verrucomicrobiota, and Desulfobacterota did not change significantly.

Claims

1. An animal model of intestinal mechanical injury, characterized in that: The animal model is inserted into the intestine of an experimental animal through a modeling experimental device to stay or rub the model, and the intestinal samples of the experimental animal are collected for intestinal mechanical damage assessment. The evaluation indicators include: the degree of colon mucosal edema, the expression level of intestinal barrier-related genes, and the relative abundance of intestinal flora; the modeling experimental device includes a brush or an intestinal mechanical damage experimental device containing a brush head structure.

2. The animal model according to claim 1, wherein The degree of colon mucosal edema includes an increase in the thickness of the colon submucosa; the expression level of intestinal barrier-related genes is reduced, and the related genes include mucus secretion genes MUC1, MUC2, MUC3 in the colon and the tight junction protein gene Occludin; The intestinal flora includes Bacteroidota and Firmicutes, and the relative abundance of Bacteroidota decreases; while the relative abundance of Firmicutes increases.

3. The animal model according to claim 1 or 2, characterized in that The animal model is divided into injury degrees by evaluation indicators, wherein the indicators include one or more of the degree of colon mucosal edema, the expression level of intestinal barrier-related genes, and the relative abundance of intestinal flora.

4. Use of an intestinal mechanical injury animal model in pathogenesis research, pathological characteristics research, related therapeutic drug screening, pharmacology research, efficacy evaluation and drug preparation.

5. An intestinal mechanical injury experimental device, characterized in that: The device comprises an intestinal brush, which comprises a brush head (1), a brush head protective cover (2) and a brush head handle (3); the tail of the brush head is connected to the brush head handle, and the head of the brush head is provided with different bristles (4); the brush head protective cover covers part of the surface area of the brush head, and the brush head protective cover controls the covered bristle part by moving.

6. The experimental device according to claim 5, characterized in that The brush head protective cover controls the covered bristle portion by rotating relative to the brush head.

7. The experimental device according to claim 5, characterized in that The bristles have different bristle stiffness and / or bristle length, and the bristle stiffness has different bristle diameters, materials, bristle densities, and processing technologies; the bristle length is X, the cross-sectional radius of the brush head protective cover is R, the length at both ends of the uncovered bristle part in the cross-sectional area of the brush head protective cover is F, and the distance between the brush head axis and F is D. The length of X satisfies the following conditions: R>X>D.

8. The experimental device according to any one of claims 5 to 7, characterized in that: The bristles are divided into mutually parallel functional areas (5), and the edges of the functional areas are parallel to the edges of the brush head protective cover.

9. The experimental device according to claim 5, characterized in that: The brush head handle and the brush head protective cover can also be provided with a rotating device (6), the rotating device connects the brush head handle and the brush head protective cover, and the rotating device is provided with internal and external threads.

10. The experimental device according to claim 5, characterized in that: The rear portion of the brush head protective cover is provided with an angle positioning groove (7), and the brush head handle is provided with an angle positioning groove corresponding to a buckle (8).

11. The experimental device according to claim 5, characterized in that: An angle positioning line (9) is provided on the surface of the brush head handle, and a rotation angle scale line (10) is provided on the surface of the brush head protective cover.

12. The experimental device according to claim 5, characterized in that: A limiting piece (11) is provided at the top end of the brush head, and the limiting piece is made of a flexible material. Preferably, the flexible material includes one of silica gel, thermoplastic elastomer, and soft rubber.

13. The experimental device according to claim 5, characterized in that The device also includes a bowel brush protective sleeve (12), the diameter of which is larger than the diameter of the bowel brush.

14. The experimental device according to claim 13, characterized in that The device also includes a positioning device (13), the diameter of which is larger than the diameter of the intestinal brush protective sleeve.

15. The experimental device according to claim 14, characterized in that A positioning groove (14) is provided on the intestinal brush protective cover, and a buckle (15) corresponding to the positioning groove is provided on the positioning device.

16. The experimental device according to claim 5 or 13, characterized in that: The brush head handle and / or the intestinal brush protective cover are provided with length scale lines.

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