Intestinal environment improver

Abstract

To provide an intestinal environment improver capable of mitigating disturbance or deterioration of the intestinal environment caused by a drug or the like.SOLUTION: The intestinal environment improver contains a compound (I) represented by the general formula (I) in the figure. (In the formula, R1 represents a hydrogen atom or alkyl group; R2 represents a hydrogen atom, carbamoyl group, alkyl group, or alkoxy group; and R3 represents a hydrogen atom, acylamino group, or sulfo group.)SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an agent for improving the intestinal environment. [Background technology]

[0002] Non-steroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenase (COX) in the arachidonic acid cascade, thereby suppressing the synthesis of prostaglandins and exerting analgesic, antipyretic, and anti-inflammatory effects. It has been reported that indomethacin, one of the above-mentioned NSAIDs, which is the first-choice analgesic, may cause disturbance or deterioration of the intestinal environment (Non-Patent Document 1).

[0003] In order to improve the disruption or deterioration of the intestinal environment caused by NSAIDs, treatment methods using probiotics and the like are being investigated. However, probiotics are used preventively over a long period of time and are not sufficient to improve the disruption or deterioration of the intestinal environment caused by the administration of NSAIDs. Furthermore, no effective treatment method is known that can provide sufficient improvement with a single administration.

[0004] Acetaminophen, known as an analgesic, is known to suppress gastric damage (Non-Patent Document 2, Non-Patent Document 3). However, proton pump inhibitors, which are also known to suppress gastric damage, are known to worsen the intestinal environment (Non-Patent Document 4). Therefore, it is not known that acetaminophen improves the intestinal environment. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Appl. Environ. Microbiol.2006 Oct;72(10):6707-6715. [Non-patent document 2] J. Pharmacol. Exp. Ther. 2014 Apr;349(1):165-173 [Non-patent document 3] J. Pharm. Pharmacol. 1978 Feb;30(2):84-87 [Non-patent document 4] Sci. Rep.2019 Nov 25;9(1):17490. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an intestinal environment improving agent capable of improving the disturbance or deterioration of the intestinal environment caused by drugs or the like. [Means for solving the problem]

[0007] The present inventors have conducted extensive research into compounds that can improve the disturbance or deterioration of the intestinal environment caused by drugs and the like, and have found that compound (I) represented by the following general formula (I), which includes acetaminophen, ethenzamide, etc., is effective in improving the intestinal environment, thereby completing the present invention.

[0008] [ka]

[0009] The present invention has the following aspects. [1] An intestinal environment improving agent containing a compound (I) represented by the following general formula (I): [ka] (In the formula, R 1 represents a hydrogen atom or an alkyl group, and R 2 represents a hydrogen atom, a carbamoyl group, an alkyl group, or an alkoxy group, and R 3 represents a hydrogen atom, an acylamino group, or a sulfo group) [2] The intestinal environment improving agent according to [1], wherein the improvement of the intestinal environment is improvement of the intestinal flora or intestinal bacterial flora. [3] The intestinal environment improving agent according to [1] or [2], wherein the improvement of the intestinal environment is improvement of disturbance or deterioration of the intestinal environment caused by drug administration. [4] The intestinal environment improving agent according to [3], wherein the drug is a nonsteroidal anti-inflammatory drug. [Effects of the Invention]

[0010] According to the present invention, an agent for improving the intestinal environment can be provided that can improve the disturbance or deterioration of the intestinal environment caused by drugs or the like. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic diagram showing the eight sections into which the rat small intestine is divided. [Figure 2A] FIG. 1 shows the results of the UniFrac distance within the Vehicle group, between the Vehicle group and the ibuprofen (IBP)-administered group, and between the Vehicle group and the ibuprofen and acetaminophen (IBP+APAP)-administered group in the UniFrac analysis of Example 1. [Figure 2B] FIG. 1 shows the results of the UniFrac distance within the Vehicle group, between the Vehicle group and the ibuprofen-administered group (IBP), and between the Vehicle group and the ibuprofen and ethenzamide-administered group (IBP+ETZ) in the UniFrac analysis of Example 1. [Figure 3] FIG. 1 shows the expression of the TNF-α gene in small intestinal mucosal samples from the vehicle group, the ibuprofen (IBP) administration group, and the ibuprofen and acetaminophen administration group (IBP+APAP) in Example 2. DETAILED DESCRIPTION OF THE INVENTION

[0012] The intestinal environment improving agent of the present invention contains a compound (I) represented by the following general formula (I): Compound (I) is preferably contained as an active ingredient of the intestinal environment improving agent of the present invention.

[0013] [ka] (In the formula, R 1 represents a hydrogen atom or an alkyl group, and R 2 represents a hydrogen atom, a carbamoyl group, an alkyl group, or an alkoxy group, and R 3 represents a hydrogen atom, an acylamino group, or a sulfo group)

[0014] In the formula (I), R 1 and R 2 The alkyl group in R preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. 1 and R 2 The alkyl group in may be linear or branched, and specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, and hexyl groups. In the formula (I), R 2 Examples of the alkoxy group in the formula (I) include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a 2,3-dihydroxypropoxy group, and the methoxy group and the 2,3-dihydroxypropoxy group are preferred. In the formula (I), R 3 The carbon chain length of the acyl group in the acylamino group is preferably 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms. In the formula (I), R 3 The sulfo group in the formula (I) also includes pharmaceutically acceptable salts, preferably sodium salts and potassium salts. Examples of the compound (I) include acetaminophen represented by the following formula (I)-1, ethenzamide represented by the following formula (I)-2, potassium guaiacolsulfonate represented by (I)-3, guaifenesin represented by (I)-4, and potassium cresolsulfonate represented by (I)-5. The above-mentioned acetaminophen and ethenzamide are drugs used as one of the main ingredients of antipyretic analgesics that suppress symptoms such as fever and headache, and potassium guaiacolsulfonate, guaifenesin, and potassium cresolsulfonate are expectorant ingredients that make it easier to expectorate phlegm, and in the present invention, they are used as one of the active ingredients of an agent for improving the intestinal environment. As the compound (I), acetaminophen and ethenzamide are more preferred since they can effectively improve the disturbance or deterioration of the intestinal environment caused by drugs and the like.

[0015] [ka]

[0016] [ka]

[0017] [ka]

[0018] [ka]

[0019] [ka]

[0020] The intestines to which the intestinal environment-improving agent of the present invention is applied include the small intestine and large intestine. The small intestine includes the duodenum, jejunum, and ileum. The large intestine includes the cecum, colon, and rectum.

[0021] Humans are naturally inhabited by bacteria, and the largest total number of bacteria in the digestive tract is found in the intestine. In the intestine, the typical bacterial density (ileum: 10 8 / mL, large intestine: 10 11 / mL) is increased in the stomach (10 3~4 / mL), and there are approximately 1,000 different bacterial species. In the present invention, "intestinal flora or intestinal bacterial flora" refers to the entire bacteria in the intestine, and "intestinal environment" refers to the intestinal ecosystem formed between intestinal bacteria or between intestinal bacteria and host cells.

[0022] The intestinal environment is controlled by mutual communication between the intestinal flora or intestinal bacterial flora and the host, and therefore, disturbance or deterioration of the intestinal flora or intestinal bacterial flora causes disturbance or deterioration of the intestinal environment. Therefore, in the present invention, "disturbance or deterioration of the intestinal environment" includes disturbance or deterioration of the intestinal environment caused by disturbance of the intestinal flora or intestinal bacterial flora. Disturbance or deterioration of the intestinal environment has an adverse effect on the host. Examples of adverse effects on the host include the induction of inflammation in the intestinal mucosa.

[0023] In the present invention, "disturbance of intestinal flora or intestinal bacterial flora" means a state in which the intestinal flora or intestinal bacterial flora is different from the normal state, thereby exerting an adverse effect on the host, and examples thereof include a state in which the intestinal flora or intestinal bacterial flora in the presence of a drug is less similar to the intestinal flora or intestinal bacterial flora in the absence of a drug, thereby exerting an adverse effect on the host.

[0024] In the present invention, "improvement of the intestinal environment" includes improving the intestinal flora or intestinal bacterial flora. The improvement of the intestinal flora or intestinal bacterial flora may be either an increase in the number or proportion of bacteria useful to the host (good bacteria), or an inhibition of a decrease in the number or proportion of bacteria useful to the host, restoring the intestinal flora or intestinal bacterial flora to a normal or near-normal state, thereby suppressing adverse effects on the host. Examples of suppressing adverse effects on the host include suppression of inflammation in the intestinal mucosa. That is, the intestinal environment-improving agent of the present invention may be an intestinal environment-improving agent that increases the number or proportion of bacteria useful to the host, or an intestinal environment-improving agent that suppresses a decrease in the number or proportion of bacteria useful to the host. Examples of bacteria useful for the host include lactic acid bacteria such as Lactobacillus bacteria, Bifidobacterium bacteria, and Streptococcus bacteria, which are also used as probiotics.

[0025] In the above, "intestinal flora or intestinal bacterial flora close to the normal state" means intestinal flora or intestinal bacterial flora that is highly similar to the intestinal flora or intestinal bacterial flora in the normal state. Therefore, "making the intestinal flora or intestinal bacterial flora close to the normal state" means, for example, increasing or not decreasing the similarity of the intestinal flora or intestinal bacterial flora to the intestinal flora or intestinal bacterial flora in the normal state, and examples include increasing the similarity of the intestinal flora or intestinal bacterial flora that has become less similar to the intestinal flora or intestinal bacterial flora in the absence of a drug due to drug administration, to the intestinal flora or intestinal bacterial flora in the absence of a drug.

[0026] It has been reported that disturbances or deterioration of intestinal flora or intestinal bacterial flora are involved in allergies, enteritis, exacerbation of intestinal bleeding, intestinal permeability, obesity, diabetes, etc., and improvement of disturbances or deterioration of intestinal flora or intestinal bacterial flora is expected to improve these symptoms.

[0027] In the intestinal environment improving agent of the present invention, the cause of the disturbance or deterioration of the intestinal environment is not particularly limited, and examples include eating habits, smoking, stress, drug administration, etc., but the intestinal environment improving agent of the present invention is preferably applied to the disturbance or deterioration of the intestinal environment caused by drug administration, and more preferably applied to the disturbance or deterioration of the intestinal environment caused by the administration of NSAIDs.

[0028] The drugs that cause the disturbance or deterioration of the intestinal environment are not particularly limited, and examples thereof include NSAIDs, such as diclofenac, indomethacin, etodolac, naproxen, meloxicam, ibuprofen, loxoprofen, celecoxib, ketoprofen, acetylsalicylic acid, and pharmaceutically acceptable salts thereof.

[0029] Routes of administration of drugs that cause disturbance or deterioration of the intestinal environment include oral administration, parenteral administration (intravenous administration, intramuscular administration, subcutaneous administration, transdermal administration, nasal administration, pulmonary administration, etc.), etc. Among these, the intestinal environment-improving agent of the present invention is preferably applied to disturbance or deterioration of the intestinal environment caused by oral administration (internal ingestion) of drugs.

[0030] When using the intestinal environment improving agent of the present invention, the single dose of compound (I) for adults is preferably 3 to 4000 mg, more preferably 3 to 2000 mg, and even more preferably 50 to 1000 mg.

[0031] In using the intestinal environment-improving agent of the present invention, the daily dose of compound (I) for adults is preferably 3 to 5,000 mg, more preferably 10 to 4,000 mg, and even more preferably 150 to 4,000 mg. For example, when acetaminophen is used as compound (I), the daily dose can be 150 to 4,000 mg, and when ethenzamide is used as compound (I), the daily dose can be 250 to 1,500 mg.

[0032] The intestinal environment-improving agent of the present invention may contain other drugs in addition to the compound (I) as needed (referred to as a combination drug). Examples of the other drugs include: Antipyretics, analgesics, and anti-inflammatory drugs (for example, salicylic acid drugs such as acetylsalicylic acid, sodium salicylate, salicylamide, and sazapyrine; propionic acid drugs such as ibuprofen and loxoprofen; fenamic acid drugs such as flufenamic acid and mefenamic acid; arylacetic acid drugs such as diclofenac sodium and indomethacin; pyrazolidine drugs such as phenylbutazone and oxyphenylbutazone; pyrimidine drugs such as bucolome; oxicam drugs such as piroxicam; pyrine drugs such as sulpyrine; isopropylantipyrine; etc.); Antihistamines (e.g., diphenhydramine hydrochloride, chlorpheniramine maleate, clemastine fumarate, carbinoxamine maleate, etc.); Antitussives (e.g., dextromethorphan hydrobromide, dihydrocodine phosphate, codine phosphate, tipepidine hibenzate, cloperastine hydrochloride, benzonatate, etc.); Expectorants (e.g., noscapine hydrochloride, bromhexine hydrochloride, etc.); Mucolytics such as L-cysteine hydrochloride, L-methylcysteine hydrochloride, and acetylcysteine; mucus repair agents such as carbocisteine; anti-inflammatory enzymes such as lysozyme chloride; anti-inflammatory agents such as glycyrrhizinic acid; hypnotics and sedatives such as allylisopropylacetylurea; mucolubricants such as ambroxol hydrochloride; antifungal agents such as terbinafine hydrochloride; Bronchodilators or asthma medications (e.g., beta-2 adrenergic receptor agonists such as pseudoephedrine, ephedrine hydrochloride, methylephedrine hydrochloride, terbutaline hydrochloride, isoproterenol, salbutamol, and terbutaline, xanthine drugs such as theophylline, aminophylline, and proxyphylline, cromoglycate, etc.); Examples include amino acids; herbal medicines; vitamins (fat-soluble vitamins such as vitamins A, D, E, K, and U; water-soluble vitamins such as vitamins B, C, and P); and the like. These other drugs can be used alone or in combination. The content of the other drugs in the intestinal environment-improving agent of the present invention is set to an appropriate prescribed amount, taking into consideration efficacy and safety, depending on the intended use of the pharmaceutical preparation. The intestinal environment-improving agent of the present invention can improve the disturbance or deterioration of the intestinal environment caused by drug administration, and therefore, among the other drugs mentioned above, antipyretic, analgesic, and anti-inflammatory drugs (for example, salicylic acid drugs such as acetylsalicylic acid, sodium salicylate, salicylamide, and sazapirin; propionic acid drugs such as ibuprofen, loxoprofen, naproxen, and ketoprofen; fenamic acid drugs such as flufenamic acid and mefenamic acid; arylacetic acid drugs such as diclofenac sodium and indomethacin; phenylbutazone, Combination drugs containing pyrazolidine drugs such as oxyphenylbutazone, pyrimidine drugs such as bucolome, oxicam drugs such as meloxicam and piroxicam, pyrine drugs such as sulpyrine, isopropylantipyrine, celecoxib, etc. are useful and preferred, and among NSAIDs, diclofenac, indomethacin, naproxen, meloxicam, ibuprofen, loxoprofen, celecoxib, ketoprofen, acetylsalicylic acid, and pharmaceutically acceptable salts thereof are particularly useful and preferred. In the combination preparation, when the drug other than Compound (I) is a drug that causes disruption or deterioration of the intestinal environment, the mass ratio of Compound (I) to the drug that causes disruption or deterioration of the intestinal environment is preferably 0.05 to 20, and more preferably 0.2 to 10. By setting the mass ratio within the above range, disruption or deterioration of the intestinal environment caused by the drug that causes disruption or deterioration of the intestinal environment can be effectively improved while maintaining the efficacy of the drug that causes disruption or deterioration of the intestinal environment.

[0033] The intestinal environment-improving agent of the present invention may contain optional ingredients other than those described above, provided that the effects of the present invention are not impaired. Examples of the optional ingredients include binders, excipients, lubricants, flavorings, flavoring agents (sweeteners, acidulants, etc.), colorants, stabilizers, coating agents, plasticizers, masking agents, etc., and these may be used alone or in appropriate combinations of two or more in appropriate amounts. Examples of binders that can be used include starch, pregelatinized starch, sucrose, gelatin, gum arabic powder, methyl cellulose, hydroxypropyl cellulose, polyvinylpyrrolidone, pullulan, and dextrin. Examples of excipients that can be used include low-substituted hydroxypropyl cellulose, corn starch, lactose, talc, crystalline cellulose (such as Ceolus), powdered sugar, sugar alcohols such as mannitol, and light anhydrous silicic acid. Examples of lubricants include magnesium stearate, calcium stearate, polyethylene glycol, talc, stearic acid, sucrose fatty acid esters, sodium stearyl fumarate, etc. Examples of flavorings include menthol, limonene, plant essential oils (peppermint oil, mint oil, lychee oil, orange oil, lemon oil, etc.), etc. Examples of sweeteners include saccharin sodium, aspartame, stevia, dipotassium glycyrrhizinate, acesulfame potassium, thaumatin, and sucralose. Examples of acidulants that can be used include citric acid, tartaric acid, malic acid, succinic acid, fumaric acid, lactic acid, and salts thereof. Examples of coating agents that can be used include hydroxypropylmethylcellulose, hydroxyethylcellulose, polyvinyl alcohol, carboxymethylcellulose, ethylcellulose, and Opadry (trade name) (manufactured by Nippon Colorcon LLC). As the plasticizer, for example, polyethylene glycol, triacetin, etc. can be used. Examples of the masking agent that can be used include titanium oxide and talc.

[0034] The administration form of the intestinal environment-improving agent of the present invention is not particularly limited. Examples include oral administration (e.g., oral administration, sublingual administration, etc.) and parenteral administration (intravenous administration, intramuscular administration, subcutaneous administration, transdermal administration, nasal administration, pulmonary administration, etc.). Among these, less invasive administration forms are preferred, and oral administration (intake) is more preferred from the viewpoint of effectively improving the disturbance or deterioration of the intestinal environment.

[0035] Examples of dosage forms of orally administered agents (internal medications) or compositions for oral administration (internal compositions) include liquid (liquid), syrup (syrup), tablets (tablets, tablets), capsules (capsules), powder (granules, fine granules), soft capsules (soft capsules with a gelatin base or the like), hard capsules (hard capsules), liquid (liquid), syrup (syrup), solid, semi-liquid, cream, and paste forms. The method for preparing the intestinal environment improving agent of the present invention into a formulation is not particularly limited, and can be carried out by a conventional method depending on the formulation.For example, compound (I), which is the active ingredient of the intestinal environment improving agent of the present invention, can be mixed with other ingredients as is, or some or all of the ingredients can be granulated or coated and then mixed to produce a granular mixture, which can be used as a granule (granule, fine granule, powder).In addition, the granular mixture can be tableted, and if necessary, further coated to form tablets. [Example]

[0036] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to the following examples.

[0037] [Example 1] (1)Animals Healthy 7-week-old male SD rats (Charles River Japan) were selected after 4 days of quarantine and acclimation. They were fasted for 16 hours or more (water was available ad libitum), then fed and subjected to the test 1 hour later.

[0038] (2) Sample (suspension) The dose of the sample to rats was 10 mL / kg body weight, and the following samples were prepared: a sample with an ibuprofen (IBP) dose of 200 mg / kg body weight, a sample (IBP+APAP) with ibuprofen (IBP) and acetaminophen (APAP) doses of 200 mg / kg body weight and 200 mg / kg body weight, respectively, and a sample (IBP+ETZ) with ibuprofen (IBP) and ethenzamide (ETZ) doses of 200 mg / kg body weight and 116 mg / kg body weight, respectively. A 5% gum arabic solution, which is the suspension solvent for each drug solution, was prepared as a control sample (vehicle).

[0039] (3) Sample administration Each sample was administered at 10 mL / kg body weight. Specifically, an amount of sample corresponding to the rat's weight (e.g., 2 mL for a 200 g rat) was placed in a disposable syringe equipped with a rat oral administration probe and administered orally by force. Five rats (n=5) were used for each experiment.

[0040] (4) Collection of test samples Sixteen hours after administration of each sample, the small intestine was removed under isoflurane anesthesia. The removed small intestine was divided into eight sections as shown in Figure 1. The seventh section from the stomach side was opened, and the contents were washed away, after which the small intestinal mucosa was collected.

[0041] (5) DNA extraction from small intestinal mucosa DNA extraction from the small intestinal mucosa was carried out using the PowerSoil DNA Isolation Kit (QIAGEN) according to the attached instructions as follows. The collected small intestinal mucosa was transferred to the PowerBead Tube provided and mixed using a vortex mixer. 60 μL of Solution C1 was then added and the tube was inverted several times. The PowerBead Tube was then fixed horizontally using the Vortex Adapter tube holder and mixed using a vortex mixer for 10 minutes. After centrifugation at 10,000 × g for 1 minute, the supernatant was transferred to a new 2 mL collection tube, 250 μL of Solution C2 was added, and the mixture was vortexed for 5 seconds. The collection tube was then incubated at 4°C for 5 minutes and centrifuged at 10,000 × g for 1 minute. The resulting supernatant was transferred to a new 2 mL collection tube, 200 μL of Solution C3 was added, and the mixture was vortexed for a short time. The collection tube was then incubated at 4°C for 5 minutes, centrifuged at 10,000 × g for 1 minute, and the supernatant was transferred to a new 2 mL collection tube. Solution C4 was mixed thoroughly, and 1.2 mL was added to the supernatant and vortexed for 5 seconds. 675 μL was then added to the MB spin column, and the DNA was adsorbed onto the MB spin column. The column was centrifuged at 10,000 × g for 1 minute, and the filtrate was discarded. The above procedure was repeated for all samples. 500 μL of Solution C5 was added to the MB Spin Column for each sample obtained above, and the column was centrifuged at 10,000 × g for 1 minute. The filtrate was discarded, and the column was centrifuged again at 10,000 × g for 1 minute to remove any remaining solution. Next, the MB Spin Column was placed in a new 2 mL Collection Tube, and 50 μL of Solution C6 was added to the center of the column to elute the DNA. The column was centrifuged at 10,000 × g for 1 minute, and the eluted DNA was used as the sample.

[0042] (6) Bacterial flora analysis The bacterial flora was analyzed using the next-generation sequencer MiSeq (Illumina) as follows. The 16S rRNA gene was amplified by PCR using the KAPA2G Robust PCR Kit (Kapa Biosystems) with the composition and conditions shown in Table 2 and Table 3, using the amplification primers for the V1-V2 region of the 16S rRNA gene (forward primer: 27Fmod consisting of the nucleotide sequence represented by SEQ ID NO: 1; reverse primer: 338R consisting of the nucleotide sequence represented by SEQ ID NO: 2) shown in Table 1. The PCR product obtained was subjected to electrophoresis to confirm the amplification of the target sequence length. DNA was purified using AM Pure XP (Beckman Coulter) according to the specified procedure. The concentration of the purified samples was measured using a Quant-iT PicoGreen dsDNA Assay Kit (Thermo Fisher Scientific), and the samples were mixed to obtain equal DNA amounts to prepare libraries. The library was purified using a MinElute PCR Purification Kit (QIAGEN) according to the specified procedure. The library concentration was measured by real-time PCR using a KAPA Library Quant Kit (Kapa Biosystems). The sequence length of the library was confirmed using a Bioanalyzer (Agilent). Sequence information was obtained using MiSeq Reagent Kits v3 (Illumina) and a next-generation sequencer, MeSeq (Illumina), according to the prescribed procedures.

[0043] [Table 1]

[0044] [Table 2]

[0045] [Table 3]

[0046] The obtained sequences were filtered for sequences containing both forward and reverse primers, sequences with a quality value of 25 or higher (indicating sequence reliability), and sequences with an alignment length of 90% or higher against database gene sequences. Only sequences that cleared the filtering were used for subsequent analysis. 3,000 sequences were randomly extracted from each sample, and the number of data was standardized. Sequences with 97% or higher homology were grouped together to create an Operational Taxonomic Unit (OTU). Representative sequences from each OTU were compared with three public databases (RDP, CORE, and NCBI) to identify bacterial species. Only bacterial species with 97% or higher homology were included; others were considered undefined. Statistical analysis was performed using the free statistical analysis software R version 3.4.4.

[0047] (7) Test results Changes in the bacterial flora due to sample administration were evaluated by the similarity of the bacterial flora obtained by UniFrac analysis. UniFrac analysis is a method that creates a phylogenetic tree using the base sequences belonging to each group (representative sequences of each OTU) and calculates the similarity of the bacterial flora between the compared samples (i.e., the overall difference in bacterial flora structure). The similarity obtained by UniFrac analysis is calculated as the UniFrac distance, and the higher the similarity of the bacterial flora between the samples, the smaller the value (approaching 0). In other words, if the distance between the vehicle group and the IBP+APAP group is statistically significantly smaller than the distance (UniFrac distance) between the vehicle group and the IBP-treated group, it indicates that the IBP+APAP group has a higher similarity of its bacterial flora to the vehicle group than the IBP-treated group. Similarly, if the distance between the vehicle group and the IBP+ETZ group is statistically significantly smaller than the distance between the vehicle group and the IBP-treated group (UniFrac distance), this indicates that the IBP+ETZ group has a more similar bacterial flora to the vehicle group than the IBP-treated group. The results of the UniFrac distance within the vehicle group and between the vehicle group and the drug-treated groups in the UniFrac analysis (weighted) are shown in Figures 2A and 2B. In Figure 2A, both the IBP-administered and IBP+APAP-administered groups had bacterial flora that was significantly different from that of the vehicle group. However, the IBP+APAP-administered group had a bacterial flora that was significantly closer to that of the vehicle group than that of the IBP-administered group. Also, in Figure 2B, the IBP-administered group had a bacterial flora that tended to differ from that of the vehicle group. However, the IBP+ETZ-administered group had a bacterial flora that was significantly closer to that of the vehicle group than that of the IBP-administered group. These results indicate that the changes in the bacterial flora caused by IBP administration could be improved by APAP or ETZ administration to a bacterial flora closer to that of the vehicle group. The Steel-Dwass test was used for statistical tests shown in Figures 2A and 2B.

[0048] [Example 2] Test samples were collected from the small intestine of rats in the same manner as in Example 1 (1) to (4). RNA was extracted from the obtained test samples using an RNeasy Mini Kit (QIAGEN), and cDNA was synthesized using ReverTra Ace® qPCR Master Mix with gDNA Remover FSQ-301 (Toyobo Co., Ltd.). Using this sample, TNFα expression was confirmed by real-time PCR. The results are shown in Figure 3. 18S rRNA was used as an endogenous control for gene expression. Primers with the sequences shown in Table 4 were used for real-time PCR.

[0049] [Table 4]

[0050] TNFα is a proinflammatory cytokine, and its overexpression indicates an inflammatory response. As shown in Figure 3, TNFα gene expression was significantly elevated only in the IBP-treated group compared with the vehicle group (P < 0.05 vs. vehicle, Dunnett's test), whereas expression in the IBP + APAP-treated group was comparable to that in the vehicle group. Thus, the intestinal microbiota in the IBP-treated group (Figure 2A) induced inflammation in the intestinal mucosa, indicating that this change in the intestinal microbiota worsened the intestinal environment. Furthermore, the intestinal microbiota in the IBP + APAP-treated group (Figure 2A) did not induce inflammation in the intestinal mucosa, suggesting that APAP administration either restored the deteriorated intestinal environment to a near-normal state or suppressed the deterioration of the intestinal environment caused by IBP administration.

Claims

1. An intestinal environment improving agent containing a compound selected from acetaminophen and ethenzamide, The intestinal environment improving agent, wherein the improvement of the intestinal environment is improvement of disturbance or deterioration of the intestinal environment caused by drug administration.

2. The intestinal environment improving agent according to claim 1 , wherein the improvement of the intestinal environment is improvement of the intestinal flora or intestinal bacterial flora.

3. The intestinal environment improving agent according to claim 1 or 2, wherein the drug is a nonsteroidal anti-inflammatory drug.

4. An intestinal environment improving agent described in any one of claims 1 to 3, wherein the route of administration of the drug is oral administration.

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