Oral composition

Abstract

To provide an oral composition that selectively and effectively promotes the growth of bacteria belonging to the genus Neisseria within the oral microbiota.SOLUTION: An oral composition comprising the following components (A) and (B): (A) a nitrate ion-supplying compound, and (B) one or two or more carbonate compounds selected from carbonate, bicarbonate, and sesquicarbonate.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an oral composition. [Background technology]

[0002] The oral cavity is home to a wide variety of bacteria, and oral flora, consisting of colonies of these bacteria, exists in various locations, such as the tooth surfaces, gums, gingival margin, palate, buccal mucosa, and tongue surface and dorsum. This oral flora contains not only pathogenic bacteria involved in oral diseases such as dental caries and periodontal disease, but also non-pathogenic bacteria as resident bacteria. Maintaining a balance between these non-pathogenic and pathogenic bacteria is believed to be highly useful in preventing or suppressing the onset and progression of oral diseases.

[0003] In this context, various studies on oral flora are being conducted. For example, Patent Document 1 discloses an oral composition containing an ester compound of a specific unsaturated fatty acid and a polyhydric alcohol, xylitol, etc., and an oil-soluble antioxidant, in an attempt to selectively promote the growth of Streptococcus gordonii, a normal oral flora, and increase its abundance. Furthermore, Patent Document 2 reports that adding a nitrogen source such as nitrate to the composition can cause oral Neisseria bacteria to produce nitric oxide, thereby favorably controlling the bacterial composition of the oral flora.

[0004] Furthermore, Patent Document 3 discloses an oral Neisseria mucosa increase agent containing a nitrate ion supplying compound and one or more sugar alcohols selected from erythritol, xylitol, and mannitol as active ingredients, in an attempt to increase the content of Neisseria mucosa in the oral cavity and thereby enhance the possibility of preventing or treating periodontal disease. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-20869 [Patent Document 2] US Patent Application Publication No. 2016 / 0151428 [Patent Document 3] Japanese Patent Publication No. 2022-151714 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the composition described in Patent Document 1 focuses solely on Streptococcus bacteria as a normal oral flora and on Porphyromonas bacteria as a pathogenic bacterium, merely confirming the balance of their growth, and does not specifically consider selectively promoting the growth of Neisseria bacteria. Furthermore, Patent Document 2 only describes the so-called probiotic technology of administering microorganisms themselves to the human body, and does not disclose or suggest any technical idea of ​​promoting the growth of specific microorganisms in the oral cavity. Furthermore, even the technology described in Patent Document 3 still has room for improvement in terms of enhancing the selective and efficient growth-promoting effect of Neisseria bacteria in oral flora.

[0007] Therefore, the present invention relates to an oral composition that can selectively and effectively promote the growth of Neisseria bacteria in oral flora. [Means for solving the problem]

[0008] Therefore, the present inventors conducted extensive research to solve the above problems and discovered an oral composition that contains a nitrate ion supplying compound and a specific carbonate compound, thereby being able to selectively and effectively promote the growth of Neisseria bacteria in the oral flora.

[0009] That is, the present invention provides a composition comprising the following components (A) and (B): (A) Nitrate ion donor compound (B) One or more carbonate compounds selected from carbonates, bicarbonates, and sesquicarbonates The present invention provides an oral composition containing the above. [Effects of the Invention]

[0010] According to the present invention, it is possible to selectively promote the growth of Neisseria bacteria in the oral cavity and maintain the good taste of an oral composition. Furthermore, it has the potential to promote the growth of not only Neisseria bacteria but also bacteria of the genus Russ. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below. In the present invention, the term "oral flora" is also referred to as "oral (oral or oral cavity) flora" or "oral (oral or oral cavity) microbiota," and refers to a community formed by a wide variety of bacteria that inhabit the oral cavity. In the present invention, "improving" the oral flora means selectively promoting the growth of Neisseria and / or Russia bacteria by activating the metabolism of these bacteria in the oral cavity, thereby increasing the proportion of these Neisseria and Russia bacteria (hereinafter collectively referred to as "Neisseria, etc."). It also means selectively suppressing the growth of pathogenic bacteria, thereby increasing the proportion of these Neisseria and other bacteria in the oral flora.

[0012] Here, the genus Neisseria refers to normal oral bacteria belonging to the genus Neisseria in the family Neisseria, including Neisseria mucosa, Neisseria sicca, Neisseria flava, Neisseria subflava, Neisseria flavescens, and Neisseria elongata. Rothia species are Gram-positive cocci or bacilli belonging to the genus Rothia in the family Micrococcaceae, and are normal inhabitants of the oral cavity. The genus Rothia includes species such as Rothia aeria, Rothia mucilaginosa, and Rothia dentocariosa.

[0013] Furthermore, in the present invention, "good taste" means that when the oral composition is applied, there is no irritating sensation in the oral cavity and no unpleasant tastes such as bitterness, astringency, or saltiness are perceived.

[0014] The oral composition of the present invention contains a nitrate ion-donating compound as component (A), which is a compound capable of releasing nitrate (NO3) ions upon contact with water. Although the detailed mechanism of action of the oral composition of the present invention is unclear, it is thought that when Neisseria bacteria and the like use component (A) to produce nitric oxide in the oral cavity, the carbonate compound of component (B), which will be described later, exerts some kind of synergistic effect. As a result, these components are thought to significantly contribute to promoting the growth of Neisseria bacteria and the proportion of Neisseria bacteria in the oral flora can be rapidly increased.

[0015] Specific examples of component (A) include one or more compounds selected from alkali metal nitrates and alkaline earth metal nitrates. More specifically, the component (A) may be one or more selected from sodium nitrate, potassium nitrate, and calcium nitrate, with potassium nitrate being preferred.

[0016] From the viewpoint of increasing the growth-promoting effect of Neisseria bacteria in oral flora, the content of component (A) in the oral composition of the present invention is preferably 0.5% by mass or more, more preferably 0.8% by mass or more, even more preferably 2% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, and even more preferably 7% by mass or less. The content of component (A) in the oral composition of the present invention is preferably 0.5 to 20% by mass, more preferably 0.8 to 10% by mass, and even more preferably 2 to 7% by mass.

[0017] The oral composition of the present invention contains, as component (B), one or more carbonate compounds selected from carbonates, bicarbonates, and sesquicarbonates. Specific examples of such component (B) include one or more selected from sodium carbonate, potassium carbonate, calcium carbonate, sodium bicarbonate, potassium bicarbonate, and sodium sesquicarbonate. Among these, one or two selected from sodium carbonate and sodium bicarbonate are preferred, and sodium bicarbonate is more preferred.

[0018] From the viewpoints of more effectively increasing the growth-promoting activity of Neisseria bacteria in oral flora, further improving the growth-promoting activity of Russus bacteria in oral flora, and further improving the growth-restricting activity of Prevotella bacteria and Veillonella bacteria, the content of component (B) in the oral composition of the present invention is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 0.8% by mass or more, even more preferably 1.5% by mass or more, and even more preferably 2.5% by mass or more, and preferably 18% by mass or less, more preferably 15% by mass or less, even more preferably 12% by mass or less, still more preferably 9% by mass or less, and even more preferably 7% by mass or less. The content of component (B) in the oral composition of the present invention is preferably 0.1 to 18% by mass, more preferably 0.5 to 15% by mass, even more preferably 0.8 to 12% by mass, even more preferably 1.5 to 9% by mass, and even more preferably 2.5 to 7% by mass.

[0019] The mass ratio ((B) / (A)) of the content of component (B) to the content of component (A) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 10 or less, more preferably 9 or less, and even more preferably 7 or less, from the viewpoints of further effectively increasing the growth-promoting effect on Neisseria bacteria in oral flora, further improving the growth-promoting effect on Russus bacteria in oral flora, and further improving the growth-restricting effect on Prevotella bacteria and Veillonella bacteria. The mass ratio ((B) / (A)) of the content of component (B) to the content of component (A) is preferably 0.01 to 10, more preferably 0.05 to 9, and even more preferably 0.1 to 7.

[0020] Furthermore, when the content of component (A) is 2% by mass or more, the mass ratio of the content of component (B) to the content of component (A) ((B) / (A)) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, even more preferably 0.3 or more, still more preferably 0.5 or more, preferably 10 or less, more preferably 4 or less, even more preferably 2 or less, and still more preferably 1.5 or less, from the viewpoint of further effectively increasing the growth-promoting effect of Neisseria bacteria in oral flora, further improving the growth-promoting effect of Russia bacteria in oral flora, and further improving the growth-restricting effect of Prevotella bacteria and Veillonella bacteria. The mass ratio of the content of component (B) to the content of component (A) ((B) / (A)) is preferably 0.01 to 10, more preferably 0.05 to 4, even more preferably 0.1 to 2, still more preferably 0.3 to 2, and even more preferably 0.5 to 1.5.

[0021] The oral composition of the present invention preferably further contains an organic acid salt (C) from the viewpoints of enhancing the growth-promoting effect on Neisseria bacteria in oral flora, more effectively increasing the growth-promoting effect on Neisseria bacteria in oral flora, further improving the growth-promoting effect on Russus bacteria in oral flora, and further improving the growth-restricting effect on Prevotella bacteria and Veillonella bacteria. Specific examples of component (C) include one or more selected from citrate, gluconate, succinate, fumarate, lactate, malate, and tartrate. Of these, citrate, gluconate, succinate, fumarate, lactate, and malate are preferred, and citrate is more preferred. Examples of salts include metal salts such as sodium, potassium, magnesium, aluminum, calcium, etc. Among these, sodium salts and potassium salts are preferred. More specifically, among these components (C), sodium citrate is preferred from the viewpoint of effectively improving the oral bacterial flora while maintaining a good taste.

[0022] The content of component (C) in the oral composition of the present invention is preferably 0.4% by mass or more, more preferably 0.8% by mass or more, even more preferably 1.5% by mass or more, still more preferably 2.5% by mass or more, and preferably 18% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, and still more preferably 4.5% by mass or less, from the viewpoints of increasing the growth-promoting activity of Neisseria bacteria in oral flora, more effectively increasing the growth-promoting activity of Neisseria bacteria in oral flora, further improving the growth-promoting activity of Russus bacteria in oral flora, further improving the growth-restricting activity of Prevotella bacteria and Veillonella bacteria, and effectively maintaining a good taste as an oral composition. The content of component (C) in the oral composition of the present invention is preferably 0.4 to 18% by mass, more preferably 0.8 to 8% by mass, even more preferably 1.5 to 5% by mass, and still more preferably 2.5 to 4.5% by mass.

[0023] The mass ratio ((C) / (A)) of the content of component (C) to the content of component (A) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.08 or more, and preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less, from the viewpoints of effectively promoting the growth of Neisseria bacteria in oral flora while maintaining good taste as an oral composition, further effectively increasing the growth-promoting activity of Neisseria bacteria in oral flora, further improving the growth-promoting activity of Russus bacteria in oral flora, and further improving the growth-restricting activity of Prevotella bacteria and Veillonella bacteria. The mass ratio ((C) / (A)) of the content of component (C) to the content of component (A) is preferably 0.01 to 10, more preferably 0.05 to 8, and even more preferably 0.08 to 6.

[0024] The mass ratio ({(B)+(C)} / (A)) of the total content of component (B) and component (C) to the content of component (A) is preferably 0.01 or more, more preferably 0.02 or more, even more preferably 0.1 or more, and preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less, from the viewpoints of increasing the growth-promoting effect on Neisseria bacteria in oral flora, more effectively increasing the growth-promoting effect on Neisseria bacteria in oral flora, further improving the growth-promoting effect on Russus bacteria in oral flora, further improving the growth-restricting effect on Prevotella bacteria and Veillonella bacteria, and effectively maintaining good taste as an oral composition. The mass ratio ({(B)+(C)} / (A)) of the total content of component (B) and component (C) to the content of component (A) is preferably 0.01 to 20, more preferably 0.02 to 10, and even more preferably 0.1 to 5.

[0025] The oral composition of the present invention contains water. In the present invention, water refers to the total amount of water contained in the oral composition, including not only purified water or the like contained in the oral composition but also the water contained in each of the components contained therein. By containing such water, the components contained therein can be well dissolved or dispersed, thereby fully exerting the desired effects.

[0026] Specifically, when the oral composition of the present invention is a liquid oral composition such as a mouthwash or liquid dentifrice, the content of water in the oral composition of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and preferably 99.7% by mass or less, more preferably 99.5% by mass or less, and even more preferably 99.4% by mass or less. Furthermore, when the oral composition of the present invention is a liquid oral composition such as a mouthwash or liquid dentifrice, the content of water in the oral composition of the present invention is preferably 50 to 99.8% by mass, more preferably 70 to 99.5% by mass, and even more preferably 80% by mass or more and 99.4% by mass or less. Furthermore, when the oral composition of the present invention is a dentifrice composition such as a toothpaste or a tooth powder, the content of water in the oral composition of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 60% by mass or less, more preferably 55% by mass or less. Also, when the oral composition of the present invention is a dentifrice composition such as a toothpaste or a tooth powder, the content of water is preferably 5 to 60% by mass, more preferably 10 to 55% by mass.

[0027] The oral composition of the present invention may further contain a fluorine-containing compound (D) from the viewpoint of more effectively enhancing the growth-promoting effect on Neisseria bacteria in the oral flora of dental plaque biofilm and from the viewpoint of sustaining the improving effect on the oral flora. Specific examples of such component (D) include one or more compounds selected from the group consisting of fluoride ion-donating compounds and monofluorophosphate ion-donating compounds.

[0028] The fluoride ion supplying compound is a fluorine-containing compound other than a compound that supplies monofluorophosphate ions. Examples of such a fluoride ion supplying compound include one or more compounds selected from sodium fluoride, stannous fluoride, potassium fluoride, zinc fluoride, betaine fluoride, stannous alanine fluoride, sodium fluorosilicate, and hexylamine fluoride. Among these, sodium fluoride or stannous fluoride is preferred.

[0029] The monofluorophosphate ion supply compound may be one or more selected from sodium monofluorophosphate, potassium monofluorophosphate, magnesium monofluorophosphate, calcium monofluorophosphate, etc. Of these, sodium monofluorophosphate is preferred.

[0030] Of these, component (D) is preferably a fluoride ion supplying compound from the viewpoint of enhancing the contribution to the growth promotion of Neisseria bacteria and sustaining the effect of improving oral flora.

[0031] In the oral composition of the present invention, the mass ratio (NO3 / F) of the nitric acid (NO3) equivalent amount of the nitrate ion supply compound to the fluorine atom equivalent amount of component (D) is preferably 0.5 or more, more preferably 2 or more, even more preferably 4 or more, even more preferably 8 or more, even more preferably 12 or more, even more preferably 14 or more, preferably 50 or less, more preferably 48 or less, even more preferably 46 or less, even more preferably 44 or less, even more preferably 42 or less, and even more preferably 38 or less, from the viewpoint of increasing the growth-promoting effect on Neisseria bacteria in the oral flora and maintaining the effect of improving the oral flora. In the oral composition of the present invention, the mass ratio (NO3 / F) of the nitric acid (NO3) equivalent amount of the nitrate ion supply compound to the fluorine atom equivalent amount of component (D) is preferably 0.5 to 50, more preferably 2 to 48, even more preferably 4 to 46, still more preferably 8 to 44, even more preferably 12 to 42, and still more preferably 14 to 38.

[0032] The content of component (D) in the oral composition of the present invention, in terms of fluorine atoms, is preferably 850 ppm or more, more preferably 900 ppm or more, even more preferably 950 ppm or more, and preferably 5000 ppm or less, more preferably 2000 ppm or less, and even more preferably 1500 ppm or less. The content of component (D) in the oral composition of the present invention, in terms of fluorine atoms, is preferably 850 to 5000 ppm, more preferably 900 to 2000 ppm, and even more preferably 950 to 1500 ppm.

[0033] When component (D) is a fluoride ion-donating compound, the content of the fluoride ion-donating compound in the oral composition of the present invention is preferably 0.1 to 1.5% by mass, more preferably 0.5 to 1.4% by mass, and even more preferably 0.7 to 1.3% by mass, from the viewpoint of the growth-promoting effect on Neisseria bacteria and the sustained improvement effect on oral flora. When component (D) is a fluoride ion-donating compound, the content of the fluoride ion-donating compound in the oral composition of the present invention is preferably 0.1 to 1.5% by mass, more preferably 0.15 to 0.8% by mass, and even more preferably 0.18 to 0.35% by mass, from the viewpoint of the growth-promoting effect on Neisseria bacteria and the sustained improvement effect on oral flora. Furthermore, when component (D) is a monofluorophosphate ion supplying compound, the content of such monofluorophosphate ion supplying compound in the oral composition of the present invention is preferably 0.2 to 4 mass%, more preferably 0.4 to 2 mass%, and even more preferably 0.6 to 1.5 mass%.

[0034] The mass ratio ((D) / (B)) of the content of component (D) to the content of component (B) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 10 or less, more preferably 2 or less, and even more preferably 0.5 or less, from the viewpoint of promoting the growth of Neisseria bacteria and maintaining the effect of improving the oral flora. The mass ratio ((D) / (B)) of the content of component (B) to the content of component (D) is preferably 0.01 to 10, more preferably 0.05 to 2, and even more preferably 0.1 to 0.5.

[0035] The oral composition of the present invention preferably contains a limited amount of sulfate ester salts, from the viewpoint of improving the growth-promoting activity of Neisseria bacteria in the oral flora while avoiding a decrease in the growth-promoting effect of Neisseria bacteria, etc. Examples of such sulfate ester salts include one or more selected from alkyl sulfates, alkenyl sulfates, polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkenyl ether sulfates, and polyoxyalkylene alkyl phenyl ether sulfates.

[0036] From the viewpoint of effectively enhancing the growth-promoting effect of Neisseria bacteria in the oral flora, the content of sulfate ester salts in the oral composition of the present invention is preferably less than 0.5% by mass, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less, or it is preferable that the oral composition of the present invention does not contain sulfate ester salts.

[0037] The oral composition of the present invention may further contain one or more orthophosphates selected from monosodium dihydrogen phosphate, disodium monohydrogen phosphate, monopotassium dihydrogen phosphate, and dipotassium monohydrogen phosphate. By containing such orthophosphates, the pH of the oral composition can be maintained constant. The content of orthophosphate in the oral cavity composition of the present invention is preferably 0.0001 to 5% by mass, more preferably 0.0005 to 2% by mass, and even more preferably 0.001 to 1% by mass.

[0038] It is preferable that the oral composition of the present invention contains a limited amount of bactericide in order to avoid a decrease in the effect of promoting the growth of Neisseria bacteria and improve the growth-promoting effect of Neisseria bacteria in the oral flora.

[0039] In order to effectively enhance the growth-promoting effect of Neisseria bacteria in the oral flora, the content of the bactericide in the oral composition of the present invention is preferably less than 0.5% by mass, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less, or it is preferable that the oral composition of the present invention does not contain a bactericide.

[0040] Furthermore, among the disinfectants, it is preferable to limit the content of cationic disinfectants. Specific examples of cationic disinfectants include one or more selected from quaternary ammonium compounds and biguanide compounds. Examples of cationic disinfectants belonging to quaternary ammonium compounds include one or more selected from cetylpyridinium chloride, benzethonium chloride, depotassium chloride, benzalkonium chloride, alkyldimethylammonium chloride, alkyltrimethylammonium chloride, and methylbenzethonium chloride. Examples of cationic disinfectants belonging to biguanide compounds include one or more selected from chlorhexidine and its salts, such as chlorhexidine gluconate and chlorhexidine hydrochloride.

[0041] In order to effectively enhance the growth-promoting effect of Neisseria bacteria in the oral flora, the content of cationic bactericide in the oral composition of the present invention is preferably less than 0.5% by mass, more preferably 0.1% by mass or less, and even more preferably 0.05% by mass or less. Alternatively, it is preferable that the oral composition of the present invention does not contain any cationic bactericide.

[0042] In addition to the above-mentioned components, the oral composition of the present invention may contain appropriate additives such as solvents such as ethanol; pH adjusters; binders; humectants such as glycerin, propylene glycol, or polyethylene glycol; abrasives; sweeteners; foaming agents and foaming aids; preservatives; colorants; and fragrances, within the scope of not impairing the effects of the present invention.

[0043] From the viewpoint of enhancing the oral flora-improving effect and ensuring its sustainability, the pH of the oral composition of the present invention at 25°C is preferably 5.0 or higher, more preferably 5.5 or higher, even more preferably 6.0 or higher, and preferably 9.0 or lower, more preferably 8.5 or lower, even more preferably 8.0 or lower. The pH of the oral composition of the present invention at 25°C is preferably 5.0 to 9.0, more preferably 5.5 to 8.5, even more preferably 6.0 to 8.0. The pH of the oral composition of the present invention is a value measured at 25°C using a pH electrode.

[0044] The oral composition of the present invention selectively and effectively promotes the growth of Neisseria bacteria and effectively increases the proportion of Neisseria bacteria in the oral flora, and is therefore extremely useful as an oral composition for promoting the growth of Neisseria bacteria or for improving the oral flora. Similarly, the oral composition of the present invention is also highly useful as an oral flora-improving agent or a Neisseria growth promoter. These agents contain the above-mentioned components (A) and (B) as active ingredients and, if necessary, may contain other ingredients similar to those of the oral composition. [Example]

[0045] The present invention will be described in detail below with reference to the following examples. Unless otherwise specified in the tables, the content of each component is expressed in mass %.

[0046] <Test Example 1> The growth-promoting effect of Neisseria bacteria in dental plaque biofilm flora (increase factor (fold) and increase amount (%)) was evaluated according to the methods shown in (1) to (4) below.

[0047] (1) Plaque collection and pretreatment Dental plaque from healthy males was collected using a dental scaler, placed in a 1.5 mL tube, and washed twice with PBS(-) by centrifugation at 7,000 g for 2 minutes at room temperature. The pellet containing plaque bacteria was suspended in 300 μL of 15% glycerol solution, and the prepared plaque suspension was stored at -80°C until use. A portion of this plaque suspension was used to measure the copy number of the total bacterial rRNA16S gene in the plaque suspension using the DNA extraction method and real-time PCR described below.

[0048] (2) Preparation of a dental plaque biofilm model using dental plaque suspension culture The compositions shown in Tables 3 and 4, which use potassium nitrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), sodium bicarbonate (manufactured by Sigma-Aldrich Corporation), sodium carbonate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and sodium citrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), were diluted 10-fold with Brain Heart Infusion (BHI) medium (BD Japan) to prepare evaluation samples. 8 A culture medium containing dental plaque bacteria was prepared by diluting the culture medium to 100 copies / mL. One mL of the prepared culture medium was added to a Poly-L-Lysine Coated 24-Well Microplate (AGC Techno Glass) and cultured at 37°C under microaerobic conditions using an Anaeropack Bikouki (Mitsubishi Gas Chemical Company, Inc.) for 48 hours (Table 3) or 48 or 60 hours (Table 4) to produce dental plaque biofilms. After culture, the supernatant was carefully aspirated without disturbing the dental plaque biofilm on the bottom, and the dental plaque biofilm samples were prepared.

[0049] (3) Extraction of genomic DNA from dental plaque biofilm A 200 μL / well solution of 20 mg / mL lysozyme (Fujifilm Wako Pure Chemical Industries, Ltd.) (containing 20 mM Tris-HCl (pH 8.0), 2 mM EDTA, and 1.2% Triton X-100) was added to the dental plaque biofilm samples attached to the bottom of the plate, and the plates were incubated at 37°C for 60 minutes with shaking (160 rpm). Genomic DNA was extracted using a Dneasy Blood & Tissue kit (QIAGEN), and the proportion of each bacterium was calculated by real-time PCR using a Taqman probe. The primers and Taqman probes used and the reaction conditions for real-time PCR are shown in Tables 1 and 2.

[0050] [Table 1]

[0051] [Table 2]

[0052] (4) Calculation of the abundance ratio of each bacteria The abundance ratio (%) of each bacterium was calculated by first creating a calibration curve using PCR products with known copy numbers as standards, then calculating the copy number of the rRNA16S gene of each bacterium using the following formula. Percentage of each bacterium present (%) = (copy number of each bacterium) / (total bacterial copy number) × 100

[0053] [Examples 1 to 13, Comparative Examples 1 to 3] Compositions having the formulations shown in Tables 3 and 4 were prepared, and the bacteria were quantified according to (1) to (4) above. For Examples 1 to 13, a comparative example containing only the same amount of potassium nitrate was selected as a control example according to the potassium nitrate content in each Example and Comparative Example, and used as the evaluation standard for Evaluations 1 and 2 below. Specifically, for example, Comparative Example 1 was selected as a control example for Examples 1 to 4 shown in Table 3, and Comparative Example 2 was selected as a control example for Examples 5 to 10 shown in Table 3. For Examples 11 and 6 shown in Table 4, Comparative Example 2 containing only the same amount of potassium nitrate was selected as a control, and the bacteria were quantified for a culture time of 48 hours as described in (2) above and Table 4. For Examples 12 and 13 shown in Table 4, Comparative Example 3 containing only the same amount of potassium nitrate was selected as a control, and the bacteria were quantified for a culture time of 60 hours as described in (2) above and Table 4. Next, evaluations 1 and 2 were carried out according to the following methods. The results are shown in Tables 3 and 4.

[0054] Evaluation 1: Neisseria growth promotion effect (increase ratio (times)) Based on the quantitative bacterial counts obtained for each composition, the growth promoting effect (increase factor (fold)) of Neisseria bacteria was calculated using the following formula. Neisseria growth promotion effect (increase ratio (fold)) = (proportion of Neisseria bacteria present) / (the proportion of Neisseria present in the comparative example selected as the control)

[0055] Evaluation 2: Neisseria growth promotion effect (increase (%)) Based on the quantitative bacterial counts obtained for each composition, the growth promoting effect (increase (%)) of Neisseria bacteria was calculated using the following formula. Neisseria growth promotion effect (increase (%)) = (proportion of Neisseria bacteria present) - (the proportion of Neisseria bacteria in the comparative example selected as the control)

[0056] [Table 3]

[0057] [Table 4]

[0058] <Test Example 2 [Examples 14 to 16]> A mouthwash was prepared according to the formulation shown in Table 5, with the remainder being water to make up 100% by mass.The bacterial growth activity in saliva was evaluated according to the methods shown below (1) to (2), and the taste was evaluated according to the method below. The results are shown in Table 5.

[0059] (1) Calculation of the ratio of each bacteria Five subjects were instructed to use the mouthwash three times a day (gargling 20 mL of mouthwash for 30 seconds) for two weeks, and the bacterial ratios in stimulated saliva were compared before and after use. Furthermore, from one week before using the mouthwash until the end of the test period, the subjects were instructed to use the designated commercially available toothpaste and toothbrush to eliminate the influence of oral hygiene practices other than the use of the mouthwash. The stimulated saliva was collected by chewing commercially available paraffin wax gum for 3 minutes, and the leaked saliva was spat out into a plastic container at regular intervals. After collection, the saliva was promptly stored in a freezer at -20°C.

[0060] Next, 500 μL of stimulated saliva was collected after storage, and genomic DNA was extracted using a PureLink Microbiome DNA Purification Kit (Thermo Fisher). The proportion of each bacterium was calculated using real-time PCR with a Taqman probe. As in Test Example 1 above, the primers and Taqman probes shown in Table 1 were used, and the real-time PCR reaction conditions shown in Table 2 were followed.

[0061] (2) Calculation of the relative increase rate of each bacterium The abundance ratio (%) of each bacterium was calculated by first creating a calibration curve using PCR products with known copy numbers as standards, then calculating the copy number of the rRNA16S gene of each bacterium using the following formula. Percentage of each bacterium present (%) = (copy number of each bacterium) / (total bacterial copy number) × 100 The relative growth rate of each bacterium was calculated using the following formula. Relative increase rate of each bacteria (%) = (proportion of each bacteria after 2 weeks of use) / (proportion of each bacteria before use) x 100 A relative increase rate of 100% or more for each bacterium was judged to have a growth promoting effect, and a rate of less than 100% was judged to have a growth inhibiting effect.

[0062] 《Taste》 A mouthwash was prepared according to the formulation shown in Table 5, with the remainder being water, to make up 100% by mass. 20 mL of the mouthwash was gargled for 30 seconds, and the taste was evaluated according to the following criteria. 4: No irritation or bitterness is observed 3: Stimulating and bitter taste is observed, but at a level that does not cause problems when used. 2: Irritating and bitter taste is observed, and it is somewhat painful to use 1: There is a strong irritating and bitter taste, and it is painful to use

[0063] [Table 5]

Claims

1. The following components (A) and (B): (A) Nitrate ion supplying compound (B) One or more carbonate compounds selected from carbonates, bicarbonates, and sesquicarbonates An oral composition comprising:

2. 2. The oral composition according to claim 1, wherein the mass ratio ((B) / (A)) of the content of component (B) to the content of component (A) is 0.01 or more and 10 or less.

3. 3. The oral composition according to claim 1, wherein the content of component (B) is 0.1% by mass or more and 18% by mass or less.

4. 3. The oral composition according to claim 1, wherein component (A) is one or more selected from the group consisting of alkali metal nitrates and alkaline earth metal nitrates.

5. 3. The oral composition according to claim 1, wherein the content of component (A) is 0.5% by mass or more and 20% by mass or less.

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