Cosmetic skin care method

Abstract

The present invention provides a cosmetic skin care method for increasing the biosynthesis of GABA by resident skin symbiotic microorganisms on an individual's skin, comprising the steps of: (i) modulating microbial population balance over a region of the individual's skin to increase the number of Bacillus acnes subsp. Defendens (Cutibacteria acnes subsp. Defendens, germline type II) bacteria on the individual's skin within the region of the skin; (ii) administering a GABA precursor comprising L-glutamic acid and / or a salt thereof to the region of skin.

Description

Technical Field

[0001] This invention relates to a cosmetic skin care method that increases the biosynthesis of GABA through resident skin symbiotic microorganisms. Background Technology

[0002] The stratum corneum comprises a layer of keratinocytes embedded in a lipid matrix, which is a unique and complex mixture of polar and nonpolar lipids. Unlike biological membranes, it contains almost no phospholipids. Its main components are ceramides, cholesterol, and free fatty acids (primarily long-chain and saturated), arranged in a specific layered structure whose integrity depends not only on the mass of the constituent parts but also on their respective proportions.

[0003] Gamma-aminobutyric acid (GABA) is a biologically active four-carbon non-protein amino acid found in prokaryotes and eukaryotes. In mammals, GABA plays a major inhibitory neurotransmitter role in the central nervous system. It is also widely distributed in peripheral tissues.

[0004] Research in the field of dermatology suggests that GABA may play a variety of beneficial roles in the skin, such as stimulating the synthesis of hyaluronic acid (HA), controlling the balance between the synthesis and degradation of type I collagen, accelerating skin barrier repair, and regulating the homeostasis of the skin barrier.

[0005] It is clearly important that the synthesis of GABA be stimulated to allow it to play its important role.

[0006] The present invention solves this problem. Summary of the Invention

[0007] This invention provides a cosmetic skin care method that increases GABA biosynthesis through resident symbiotic microorganisms on an individual's skin. The method includes the following steps: (i) Modulate the microbial population balance of a region of an individual's skin to increase the defensive subspecies of Propionibacterium acnes on the individual's skin in said region of the skin. Cutibacterium acnes subsp. defending The number of phylotype II bacteria; (ii) Administering a GABA precursor containing L-glutamic acid and / or its salt to the area of ​​the skin. Detailed Implementation

[0008] As used herein, “cosmetic skin care” refers to the modification and / or improvement of the cosmetic properties of the skin, rather than the cure, treatment, or prevention of diseases or conditions. Therefore, these cosmetic properties need to be modified and / or improved in both healthy subjects and subjects with skin diseases or conditions such as psoriasis, lichen planus, folliculitis, or atopic dermatitis.

[0009] Examples of cosmetic skin care benefits within the scope of this invention include: providing a smoother, more even skin texture; improving skin elasticity or resilience; improving skin firmness; improving skin hydration or moisturizing; improving skin barrier function; and reducing the appearance of redness or spots on the skin.

[0010] As used herein, “skin” should be understood as the layers that make up the skin, from the outermost layer or stratum corneum to the innermost layer or subcutaneous tissue, both of which are included. These layers are composed of different types of cells, such as keratinocytes, fibroblasts, melanocytes, mast cells, neurons, and adipocytes. The term “skin” also includes the scalp.

[0011] As used herein, the term "resident skin symbiont" refers to microorganisms that are normally present on healthy human skin, whose interactions with the skin are neutral or beneficial, and who permanently reside on the skin surface, in the stratum corneum, and in the outer layers of the epidermis and deeper folds of the skin and hair follicles. Microbial colonization is differentially formed through physiological and topological changes in the skin and is systemically altered in different skin habitats, such as in dry, moist, and sebaceous skin. Resident skin symbiotic microorganisms are characterized by their ability to grow and multiply on the skin without invading or damaging skin tissue. Another characteristic of these microorganisms is that, in deeper skin areas, they are not easily removed by washing.

[0012] Based on serum agglutination assays, cell wall glycoside analysis, fatty acid profiles, and morphology, *Propionibacterium acnes* (… C. acnes The species is divided into three main genetic lineages (phylotypes I, II, and III). It is classified into three subspecies: Phenotype I is Propionibacterium acnes subsp. acnes (…). C. acnes subsp. acne ), phylogenetic type II is the defensive subspecies of Propionibacterium acnes ( C. acnes subsp. defending Phylogenetic type III is Propionibacterium acnes elongatum subsp. ( C. acnes subsp. elongated Based on 16S rRNA gene analysis, Propionibacterium acnes (… C. acnes The strains are also classified into multiple ribotypes (RT).

[0013] Studies have shown that Propionibacterium acnes subsp. acnes (… C. acnes subspecies acne Phylogenetic I strains (RT1, RT3, RT4, RT5, and RT8) are more frequently associated with acne. In contrast, the defensive subspecies of Propionibacterium acnes (…) C. acnes subspecies defendingPhylogenetic II strains (RT2 and RT6) are more frequently found on healthy skin, especially the RT6 subgroup, which has been found to be associated with healthy skin in 99% of cases.

[0014] acne-fighting subspecies associated with healthy skin (Propionibacterium acnes) C. acnes subsp. defending Germ type II strains exhibit a variety of strain-specific characteristics at the gene, transcription, and translation levels, which may explain their symbiotic phenotypes and their lack of association with acne. Elements that can be used to characterize such strains include the presence of a complete CRISPR / Cas gene set. Furthermore, the *Propionibacterium acnes* defensive subspecies associated with healthy skin (…) C. acnes subsp. defending Germplasm type II strains secrete only low levels of porphyrins and carry inhibitors that suppress porphyrin biosynthesis. God Genes. A growing body of evidence suggests that colonization of these strains on the skin is not only unrelated to acne, but may actually be beneficial to the skin, for example, by regulating immune cell activity and secreting protective substances.

[0015] According to step (i) of the method of the present invention, the microbial population balance of a region of an individual's skin is adjusted to increase the defensive subspecies of Propionibacterium acnes on the individual's skin in said region of the skin. Cutibacterium acnes subsp. defending The number of phylotype II. These Propionibacterium acnes ( C. acnes The strain represents a resident skin symbiotic microorganism involved in the biosynthesis of GABA.

[0016] In step (i) of the method of the present invention, this can be achieved by using a selected subspecies of Propionibacterium acnes associated with healthy skin (…). C. acnes subsp. defending Probiotics (strain type II) are used to treat the skin in the aforementioned areas to regulate the microbial balance.

[0017] Preferably, in step (i) of the method of the present invention, the microbial balance is regulated by treating the area of ​​the skin with a prebiotic such as erythritol ((2R,3S)-butane-1,2,3,4-tetraol).

[0018] Studies have shown that erythritol can promote the growth of Propionibacterium acnes, a bacterium associated with healthy skin. C. acnes The growth of ribosomal (RT) forms (RT2 and RT6) is inhibited or not promoted by acne-associated Propionibacterium acnes (RT2 and RT6). C. acnesThe growth of RT (RT1, RT3, RT4, RT5, and RT8) is promoted. Commonly, these microbial strains naturally compete for local resources and epithelial attachment sites. Instead of universally reducing microbial load and diversity, this prebiotic induces ecological changes that allow beneficial microbial strains to grow, metabolize, and / or colonize more favorably than less beneficial strains.

[0019] Probiotics and prebiotics can also be used simultaneously or sequentially.

[0020] If necessary, the antimicrobial agent can be administered to the area of ​​the skin prior to treatment with probiotics and / or prebiotics.

[0021] Suitable antibacterial agents include sulfur, benzoyl peroxide, antibacterial zinc salts (such as zinc oxide, zinc gluconate, and zinc PCA), antibacterial organic acids (such as salicylic acid, lactic acid, glycolic acid, pyruvic acid, azelaic acid, succinic acid, ferulic acid, cinnamic acid, and pyridinecarboxylic acid), cationic antibacterial agents (such as benzalkonium chloride, hexadecylpyridine chloride, and hexadecyltrimethylammonium bromide), and antibacterial essential oil active ingredients (such as thymol, eugenol, menthol, geraniol, vertenone, eucalyptol, pinocarvone, cedrol, anethole, carvacrol, juniperol, berberine, methyl salicylate, terpineol, and limonene).

[0022] A mixture of any of the above materials may also be used.

[0023] According to step (ii) of the method of the present invention, a GABA precursor containing L-glutamic acid and / or its salt is administered to the area of ​​the skin.

[0024] L-glutamic acid (L-2-aminoglutarate) has the following structural formula (I): (I) L-glutamate can appropriately correspond to the following structural formula (II): (II) Where n is 1 or 2. Suitable counterions X include ammonium, or alkali metals such as sodium or potassium, or alkaline earth metals such as calcium or magnesium.

[0025] A mixture of any of the above materials may also be used.

[0026] L-glutamic acid of formula (I) is preferably used in the method of the present invention.

[0027] Steps (i) and (ii) of the method of the present invention can be performed simultaneously or in any order.

[0028] Therefore, the composition used to carry out the method of the present invention can be formulated into a two-part composition, wherein the first part contains probiotics and / or prebiotics, together with the second part containing a GABA precursor; or alternatively, it can be formulated into a single composition containing probiotics and / or prebiotics together with a GABA precursor.

[0029] A preferred composition for carrying out the method of the present invention comprises the following components in a cosmetically acceptable vehicle: (i) 0.01 to 10%, preferably 0.1 to 5% (by weight, based on the total weight of the composition) of a GABA precursor comprising L-glutamic acid and / or its salt, and (ii) 0.01 to 10%, preferably 0.1 to 5% (based on the total weight of the composition) of erythritol.

[0030] In the composition, preferably at least 75%, more preferably at least 85%, and most preferably 100% of the GABA precursor is L-glutamic acid (based on the total weight of the GABA precursor).

[0031] The term "cosmetic acceptable" means that the medium is suitable for topical application to the skin, has good aesthetics, and does not cause any problems with ingredient compatibility, safety, or toxicity.

[0032] Suitable cosmetic media may include aqueous phases, oil phases, alcohol phases, silicone phases, or mixtures thereof, and may be in emulsion form. Emulsion consistency ranges may include lotions (also suitable for spray or aerosol delivery), cream lotions, light creams, and heavy creams.

[0033] Exemplary emulsions include water-in-oil emulsions, oil-in-water emulsions, silicone-in-water emulsions, silicone-in-polyol emulsions, polyol-in-silicone emulsions, oil-in-polyol emulsions, polyol-in-oil emulsions, wax-in-water emulsions, and water-oil-water ternary emulsions. Preferred emulsions include oil-in-water emulsions and water-in-oil emulsions.

[0034] Compositions in emulsion form and suitable for carrying out the methods of the present invention typically have an oil phase comprising one or more cosmetically acceptable fatty materials, which may be liquid or solid at room temperature (25°C).

[0035] Suitable cosmetic-acceptable fatty materials include naturally derived oils (such as sunflower seed oil, borage oil, soybean oil, castor oil, olive oil, and almond oil); esters of mono- or polyols with mono- or polycarboxylic acids, wherein at least one alcohol and / or acid contains at least one hydrocarbon chain having at least 6 carbon atoms (e.g., octyl palmitate, isopropyl myristate, isopropyl palmitate, isopropyl isostearate, hexyl laurate, isohexyl laurate, isohexyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, dihexyl decyl adipate, lauryl lactate, myristyl lactate, cetyl lactate, oleic acid ester, oleic acid ester, myristate ester, lauryl acetate, cetyl propionate). Isonononyl isononate, propylene glycol didecanoate, diisopropyl adipate, dibutyl adipate, and oleate adipate; ethers (e.g., dioctyl ether); fatty alcohols (e.g., cetyl alcohol, stearyl alcohol, and behenyl alcohol); isoparaffins (e.g., isooctane, isododecane, and isohexadecane); silicone oils (e.g., dimethyl silicone oil, cyclic silicones, and polysiloxanes); hydrocarbon oils (e.g., mineral oil, petrolatum, and polyisobutylene); fatty acids having 8 to 30 carbon atoms (e.g., stearic acid, lauric acid, palmitic acid, and oleic acid); vegetable fats (e.g., cocoa butter, coconut oil, palm oil, and shea butter); petroleum-based, natural, and synthetic waxes (e.g., lanolin wax, beeswax, carnauba wax, candelilla wax, paraffin wax, lignite wax). Wax), microcrystalline wax, ceresin (refined ceresin), ozokerite (natural ceresin), and polyethylene wax; hydrogenated oils that are solid at 25°C (e.g., hydrogenated castor oil, hydrogenated jojoba oil, hydrogenated palm oil, hydrogenated tallow, and hydrogenated coconut oil); and fatty acid esters that are solid at 25°C (e.g., C). 20-40 Alkyl stearate).

[0036] Compositions in emulsion form and suitable for carrying out the methods of the present invention typically have an aqueous phase, which may further comprise one or more organic liquids miscible with water at room temperature (25°C). Exemplary water-miscible organic liquids include monohydric alcohols and polyhydric alcohols and their derivatives, such as C2-C6 alkanols (e.g., ethanol and isopropanol); C2-C 10 Diols and polyols (e.g., glycerol, propylene glycol, butylene glycol, pentanediol, hexanediol, octyl glycol, dipropylene glycol, and diethylene glycol); C3-C 16 Glycol ethers (such as mono-, di-, or tripropylene glycol (C1-C4) alkyl ethers and mono-, di-, or triethylene glycol (C1-C4) alkyl ethers) and polyethylene glycol having 2 to 12 ethylene oxide units.

[0037] Compositions in emulsion form suitable for carrying out the methods of the present invention generally contain surfactants, such as emulsifiers and solubilizers, to homogeneously bind two or more immiscible components and to contribute to the stabilization of the composition. Emulsifiers that can be used to form O / W or W / O emulsions include sorbitan oleate, sorbitan sesquioleate, sorbitan isostearate, sorbitan trioleate, PEG-20 sorbitan isostearate, polyglycerol-3-diisostearate, oleic acid / isostearate polyglycerol ester, polyglyceryl-6 hexaricinolate, polyglycerol-4-oleate, polyglycerol-4-oleate / PEG-8 propylene glycol cocoate, polyglycerol-2-dihydroxystearate, PEG-30-dihydroxystearate, oleamide DEA, TEA myristate, TEA stearate, magnesium stearate, sodium stearate, potassium laurate, and potassium ricinoleate. (ricinoleate), sodium cocoate, sodium tallow, potassium castorate, sodium oleate, cetyl phosphate, diethanolamine cetyl phosphate, potassium cetyl phosphate, sodium glycerol oleate phosphate, dimethicone copolyol, cetyl dimethicone copolyol, octyl dimethicone ethoxy glucoside copolyol, dimethicone copolyol crosspolymer, and lauryl polymethylsiloxane copolyol.

[0038] The compositions used to implement the methods of the present invention can also be formulated in a single-phase carrier, such as a hydrophobic or hydrophilic liquid. Suitable hydrophobic liquid carriers include liquid polyorganosiloxanes, mineral oils, hydrogenated polyisobutylene, polydecene, paraffins and isoparaffins with at least 10 carbon atoms, aliphatic or aromatic ester oils (e.g., isopropyl myristate, lauryl myristate, isopropyl palmitate, diisopropyl sebacate, diisopropyl adipate, and C... 12 -C 15 Alkyl benzoates), polyglycol ethers (e.g., polyglycol butanol ether), and mixtures thereof. Suitable hydrophilic liquid carriers include water, mono- or poly-fatty alcohols (e.g., ethanol and isopropanol) having 2 to 8 carbon atoms, preferably 2 or 3 carbon atoms, oligomeric glycol ethers (e.g., dipropylene glycol) having 2 to 5 repeating units, and mixtures thereof.

[0039] The liquid composition used to carry out the method of the present invention can be thickened, for example, by using one or more water-soluble or colloidal water-soluble polymer thickeners. Suitable water-soluble or colloidal water-soluble polymer thickeners include hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinyl alcohol, acrylate / ethyl acrylate copolymers, carboxyvinyl polymers, cross-linked polyacrylate polymers, and polyacrylamide polymers.

[0040] Solid form compositions used to carry out the methods of the present invention, such as gels and rods, generally contain one or more structuring agents in an amount of about 1% to about 35% (by weight based on the total weight of the composition), depending on the desired product consistency. Examples of structuring agents include fatty acid gelling agents selected from the following: saturated fatty acids or hydroxy acids containing about 8 to 30 carbon atoms and their salts, esters, or amides (e.g., sodium stearate and potassium stearate, 12-hydroxystearic acid, 12-hydroxystearate, and 12-hydroxystearamide); saturated, unsubstituted monohydric fatty alcohols containing about 8 to 30 carbon atoms (e.g., cetyl alcohol, myristyl alcohol, and stearyl alcohol); acyl amino acid derivatives, such as N-lauroyl-L-glutamic acid di-n-butyramide; amide derivatives of di- or tri-carboxylic acids, such as alkyl N,N′-dialkylsuccinimide; and inorganic particulate thickeners selected from siliceous and aluminosilicate materials (e.g., ignited silica, bentonite, lithium montmorillonite, colloidal magnesium aluminum silicate, and organoclays, such as stearalkonium chloride bentonite). Bentonite, distearate dimonium hectorite, quaternium-90 bentonite, quaternium-18 bentonite and quaternium-18 lithium montmorillonite; and petroleum-based, natural and synthetic waxes (e.g. lanolin wax, beeswax, carnauba wax, candelilla wax, castor wax, montan wax, paraffin wax, lignite wax, microcrystalline wax, ceresin (refined ceresin), ozokerite (natural ozokerite), polymethylene and polyethylene waxes.

[0041] Any combination of the above-mentioned materials or product forms may also be used.

[0042] The composition used to implement the method of the present invention may contain additional skin care active ingredients to improve the physical and / or aesthetic properties of the skin.

[0043] Examples of additional skin care active ingredients include vitamins, minerals and / or antioxidants, skin anti-hyperpigmentation agents, sunscreens, anti-irritants, exfoliants, and mixtures thereof.

[0044] Suitable vitamins, minerals, and / or antioxidants include natural plant antioxidants derived from plant materials, such as fruit, vegetable, herb, and spice extracts (e.g., goji berry, white tea, rosemary, green tea, grape seed, and lemongrass extracts); vitamin A and its precursors or derivatives (e.g., beta-carotene, retinyl palmitate); vitamin B3 and its precursors or derivatives (e.g., niacinamide); vitamin B5 and its precursors or derivatives (e.g., panthenol and its precursors or derivatives); vitamin C and its precursors or derivatives (e.g., tetrahexyldecyl ascorbate, ascorbyl palmitate); vitamin E and its precursors or derivatives (e.g., d-α-tocopherol, tocopheryl acetate); vitamin K and its precursors or derivatives; selenium and its derivatives (e.g., L-selenomethionine); and alpha-lipoic acid.

[0045] Suitable skin anti-hyperpigmentation agents include natural plant agents derived from plant materials (such as bearberry leaves). Arctostaphylos patula ) and white bear fruit ( Arctostaphylos viscida ) extract, Phyllanthus emblica ( Emblica officinalis ) extract, rough cap fruit ( Mitracarpus scaber Extracts, Bearberry (Arbutin) extract, Silkworm (Mulberry) extract, White mulberry (White Mulberry) Extract, Broussonetia paper-bearing (Broussonetia papyrifera) extract, licorice extract, acerola cherry extract, chlorella ( Chlorella common ) extract, Cape Aloe ( Aloe ferrous ) extract and Sorrel ( Western Sorrel Extracts); synthetic or natural glycosamines (such as glucosamine, N-acetylglucosamine, glucosamine sulfate, mannosamine, N-acetylglucosamine, galactosamine, N-acetylgalactosamine and their hydrochlorides); retinoids (such as retinol, retinaldehyde, retinoic acid and C-retinol). 2-20 Esters, such as retinyl palmitate, retinyl acetate, retinyl propionate, retinyl linoleate, and retinyl oleate; kojic acid and its C 2-20Esters (e.g., kojic acid monobutyrate, kojic acid monodecanoate, kojic acid monopalmitate, kojic acid monostearate, and kojic acid monobenzoate); hydroquinone, hydroquinone monomethyl ether, hydroquinone monoethyl ether, hydroquinone monobenzyl ether, α- and β-arbutin, deoxyarbutin (4-[(tetrahydro-2H-pyran-2-yl)oxy]phenol), hydroquinone monomethyl ether (4-hydroxyanisole), glutathione, cysteine, N-acetyl-L-cysteine, azelaic acid, magnesium ascorbate phosphate, sodium ascorbate phosphate, peroxides (e.g., hydrogen peroxide, zinc peroxide, sodium peroxide, and benzoyl peroxide). Acyl); 3-aminotyrosine, glycyrrhizic acid, and 4-substituted resorcinol derivatives (e.g., 4-methylresorcinol, 4-ethylresorcinol, 4-propylresorcinol, 4-isopropylresorcinol, 4-butylresorcinol, 4-pentylresorcinol, 4-hexylresorcinol, 4-heptylresorcinol, 4-octylresorcinol, 4-nonylresorcinol, 4-decylresorcinol, 4-undecylresorcinol, 4-dodecylresorcinol, 4-cyclopentylresorcinol, 4-cyclohexylresorcinol, 4-cycloheptylresorcinol, and 4-cyclooctylresorcinol).

[0046] Appropriate sunscreens protect the skin from ultraviolet (UV) solar radiation falling into the UVB range (wavelengths from 290 nm to 320 nm) and the UVA range (wavelengths from 320 nm to 400 nm). Examples of sunscreen agents include methoxycinnamate derivatives (such as octyl methoxycinnamate and isoamyl methoxycinnamate); camphor derivatives (such as 4-methylbenzyl camphor, camphor benzalkonium methyl sulfate, and terephthalimide dicamphor sulfonic acid); salicylate derivatives (such as octyl salicylate and homolyl ester); sulfonic acid derivatives (such as phenylbenzimidazole sulfonic acid); benzophenone derivatives (such as dioxybenzone, sulphone, and oxybenzone); benzoic acid derivatives (such as aminobenzoic acid and octyl dimethyl para-aminobenzoate); octocrylene, diethylhexylbutamidotriazinone, octyltriazinone, butyl methoxydibenzoylmethane, cresoltrazol trisiloxane, menthol anthranilate, and inorganic UV-absorbing particles (such as zinc oxide and titanium dioxide).

[0047] Suitable anti-irritants include allantoin, aloe vera, alpha-bisabolol, caffeine, chamomile extract, and kola nut. Cleaned cola Extracts, cucumber extract, dipotassium glycyrrhizate, glycyrrhizic acid, green tea extract, lecithin or hydrogenated lecithin, licorice extract, Oats(Oat) flake extract, tea tree oil, salicylic acid, acetylsalicylic acid, strontium acetate, strontium chloride, strontium nitrate, fatty acids with anti-irritant properties (such as linoleic acid and linolenic acid), and aromatic aldehydes with anti-irritant properties (such as 4-methoxybenzaldehyde, 4-ethoxybenzaldehyde, 4-butoxybenzaldehyde, and 4-pentoxybenzaldehyde).

[0048] Suitable exfoliants include benzoyl peroxide, benzoic acid, 3-hydroxybenzoic acid, salicylic acid, acetic acid, trichloroacetic acid, 1-pyrrolidone-5-carboxylic acid, α-hydroxy acids (such as glycolic acid, lactic acid, malic acid, tartaric acid, and citric acid); β-hydroxy acids (such as β-hydroxybutyric acid); α-keto acids (such as pyruvate, 2-oxopropionic acid, 2-oxobutyric acid, and 2-oxovaleric acid); and oxacids (such as 3,6,9-trioxaundecanedioic acid).

[0049] A mixture of any of the above materials may also be used.

[0050] The composition used to implement the method of the present invention may also contain additional functional ingredients to improve the physical and / or aesthetic properties of the composition.

[0051] Examples of suitable additional functional ingredients include water-soluble or colloidal polymer thickeners (such as hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose, polyquaternium-10, carrageenan, guar gum, hydroxypropyl guar gum, xanthan gum, polyvinyl alcohol, acrylate / ethyl acrylate copolymers, carboxyvinyl polymers, cross-linked polyacrylate polymers, and polyacrylamide polymers); structuring clays (such as magnesium aluminum silicate, ata gel, bentonite, montmorillonite, and lithium montmorillonite); inorganic pigments (such as titanium dioxide, zirconium oxide, cerium oxide, zinc oxide, iron oxide, chromium oxide, and iron blue); organic pigments (such as carbon black and barium, strontium, calcium, and aluminum lakes); pearlescent agents (such as mica coated with titanium dioxide and / or iron oxide); dyes; preservatives (such as disodium EDTA, benzyl alcohol, methylparaben, phenoxyethanol, propylparaben, ethylparaben, butylparaben, and isobutylparaben); pH adjusters; and fragrances.

[0052] A mixture of any of the above materials may also be used.

[0053] Package The compositions used to carry out the methods of the present invention can be packaged in suitable containers to suit their viscosity and the intended use by the consumer. For example, lotions or creams can be packaged in bottles or roller applicators, propellant-driven aerosol devices, or containers equipped with pumps suitable for finger operation. When the composition is a cream, it can simply be stored in non-deformable bottles or squeeze containers, such as tubes or cans with lids.

[0054] use The cosmetic composition used to carry out the method of the present invention can be appropriately applied to the skin once or twice daily. Generally, an amount corresponding to about 1 to 2 ml of the composition is uniformly applied to the treatment area twice daily for at least 7 days, preferably at least 30 days.

[0055] The invention is further illustrated by the following non-limiting embodiments.

[0056] Example Step i: Erythritol as a defensive subspecies of Propionibacterium acnes ( C. acnes subsp. defending Selective prebiotics of phylogenetic type II Erythritol was evaluated at different concentrations (5% and 10%) for its ability to increase *Propionibacterium acnes* (…). Cutibacterium acnes The growth and acid-producing abilities of two different strains: one associated with healthy skin. (1) Another type of acne-related (2) (1) Defensive subspecies of Propionibacterium acnes ( Cutibacterium acnes subsp. defending ATCC 11828, germline II, ribosomal RT2) (2) Propionibacterium acnes subsp. acnes ( Cutibacterium acnes subsp. acne ATCC 6919, germline type I, ribosomal type RT1).

[0057] Inoculum for the test bacteria was prepared in the recommended growth medium under anaerobic conditions at 37°C for 24 hours. The inoculum was centrifuged and resuspended in sterile distilled water to a 50% liquid medium. The inoculum was adjusted to a concentration of 1.5–5 × 10⁻⁶. 8 Cell density of CFU / ml.

[0058] Add 90 µl of erythritol test solution, 90 µl of 50% liquid culture medium, and 20 µl of bacterial inoculum to a 96-well PreSens HydroPlate®. A growth control is included, in which sterile distilled water is used instead of the test solution, and 27.5% and 100% culture medium are added. For HydroPlate®, a pH buffer control is also included.

[0059] Fluorescence was dynamically read from HydroPlate® at 37°C for 96 hours. PreSens calibration software pHSolver_v10 was used for part of the analysis.

[0060] Table 1 below shows the calculated acidity produced by the tested bacterial species after incubation with erythritol, compared with the growth control.

[0061] Table 1

[0062] The results show that when acne-associated probiotics (A. acnes) Cutibacterium acnes When comparing Propionibacterium acnes (ATCC 6919) with corresponding controls, the proportion of healthy-associated Propionibacterium acnes (ATCC 6919) was significantly reduced. Cutibacterium acnes According to ATCC 11828, the acid production is significantly greater when erythritol is added according to the present invention.

[0063] Step ii: Through health-associated acne bacteria (Propionibacterium acnes) Cutibacterium acnes GABA biosynthesis The ELISA kit was used to assess the effects of L-glutamate on healthy-associated acne bacteria (Propionibacterium acnes) when using L-glutamate as a substrate. Cutibacterium acnes ATCC 11828) and Propionibacterium acnes associated with acne ( Cutibacterium acnes GABA biosynthesis (ATCC 6919).

[0064] Inoculum of the test bacteria was prepared in the recommended growth medium under anaerobic conditions at 37°C for 48 hours. The inoculum was centrifuged and resuspended in sterile distilled water to a 25% liquid medium. The inoculum was adjusted to an optical density (OD) of 1 at 600 nm. An 8 mg / ml solution of L-glutamic acid was prepared in 25% medium as a substrate.

[0065] Prepare the test conditions and incubate with shaking at 37°C for 24 hours. For this purpose, add 5 ml of each isolate with an OD of 1 to 5 ml of 8 mg / ml L-glutamic acid (substrate). Prepare controls, including cases without substrate (isolate only in the culture medium) and cases with substrate (L-glutamic acid only in the culture medium) in the experiment.

[0066] After 24 hours of incubation, the amount of GABA produced was measured using an ELISA kit following the manufacturer’s instructions (ab287792 – Human QuickDetect™ GABA ELISA kit, available from Abcam plc, Cambridge UK).

[0067] Table 2 below shows the amount of GABA produced by the tested bacterial species after incubation with the substrate L-glutamate, compared with the control.

[0068] Table 2

[0069] Overall, the results show that *Propionibacterium acnes* (PAC) is associated with health conditions. Cutibacterium acnesATCC 11828) can produce GABA when L-glutamate is supplemented, while Propionibacterium acnes (A. acnes) associated with acne... Cutibacterium acne (ATCC 6919) and the control group are not compatible.

[0070] Table 3 below shows the skin care compositions used to implement the methods of the present invention.

[0071] Table 3 Skin Care Washes

Claims

1. A cosmetic skin care method that increases GABA biosynthesis through resident symbiotic microorganisms on an individual's skin, the method comprising the following steps in sequence: (i) Modulate the microbial population balance of a region of an individual's skin to increase the defensive subspecies of Propionibacterium acnes on the individual's skin in said region of the skin. Cutibacterium acnes subsp. defendens The number of phylotype II bacteria, wherein the microbial balance is adjusted by applying a cosmetic composition containing erythritol ((2R,3S)-butane-1,2,3,4-tetraol) to the area of ​​the skin, and (ii) Applying a cosmetic composition containing a GABA precursor to the area of ​​skin, wherein the GABA precursor comprises L-glutamic acid and / or its salt.

2. The method of claim 1, wherein at least 75% of the GABA precursor is L-glutamic acid (based on the total weight of the GABA precursor by weight).

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