Use of conjugated fatty acids for microbiome benefit and compositions comprising the same

Abstract

The present invention relates to use of conjugated fatty acids; and compositions comprising them for delivering microbiome benefit to skin. Particularly, the present invention is useful in formulating tropical compositions that provides microbiome benefit to skin, such as, inhibition of growth of non-commensal bacteria, like E. coli, S. aureus, P. aeruginosa and P. acnes, while growth or no change in commensal bacteria, like S. epidermis.

Description

[0001] USE OF CONJUGATED FATTY ACIDS FOR MICROBIOME BENEFIT AND COMPOSITIONS COMPRISING THE SAME

[0002] Field of the Invention

[0003] The present invention relates to use of conjugated fatty acids (CFAs) and compositions comprising them for delivering microbiome benefit to skin. Particularly, the present invention is useful in formulating tropical compositions that provides microbiome benefit to skin. The microbiome benefit herein defined by inhibition of growth of non-commensal bacteria while growth or no change in commensal bacteria.

[0004] Backa round of the Invention

[0005] Skin in mammals is considered as one of the largest organs in the body, especially one which has the largest surface area. Skin forms the first line of defence against microorganisms which may invade the body though the air, water, food or material that may come in contact with the body. When the body is infected on the skin or systemically, traditional approach to such hygiene problems has been to treat the skin / body with antimicrobial actives that reduce or kill the germs. Recent research indicates that a lot of the bacteria that permanently reside on the skin (called skin commensal bacteria) do not actually cause infections, rather they are beneficial bacteria that protect the skin against disease causing pathogens. Several mechanisms have been proposed to explain the protection and some of the popular ones are: physically occupying space on skin to prevent colonization of pathogens; producing metabolites that ward off harmful possibly pathogenic organisms; generating metabolites that strengthen the innate defence mechanisms to prevent infection by harmful pathogens; and providing other benefits such as maintaining skin pH, barrier function, etc. Thus, of late, there is a trend in moving away from the approach of treating the skin with broad spectrum antimicrobial actives to kill all microorganisms present on skin (or any other part of the body) as a means of treating infections. Rather, the approach is more towards targeted or selective inhibition / killing of the harmful microorganism or noncommensal microorganism. This ensures that the skin microbiome is maintained in a healthy balanced state for long term hygiene and health.

[0006] In this regard, US 201 1 / 0105612 discloses methods and compositions for suppressing the growth of microorganisms on selected areas of the skin for an extended period of time, such as one hour, twenty-four hours, seventy-two hours, or longer. An area of the skin is selected for the suppression of the growth of microorganisms and a microorganism growth suppressing agent is topically applied to the selected area of the skin. The microorganism growth suppressing agent may be comprised in a pharmacologically acceptable vehicle such as an emulsion or soap. The microorganism growth suppressing agent comprises free conjugated fatty acid such as conjugated linoleic acid.

[0007] Despite the prior arts, there remains a need for improved compositions which can provide selective inhibition of harmful non-commensal bacteria in skin, like E. coli, P. aeruginosa, P. acnes and S. aureus. The present inventors, in looking to solve the problem directed their research to boosting the number and functionality of skin commensal bacteria through use of prebiotics or Selective Fermentation Inducers (SFI).

[0008] They found, during the course of the research, that the population of skin non-commensal bacteria like S. aureus, was decreased whilst the population of skin commensal bacteria like S. epidermidis can be well maintained or further grown on skin, through use of conjugated fatty acids (CFA) e.g., conjugated linoleic acid (CLA). This efficacy can be further enhanced through use of polyols e.g., glycerol, in combination with the CFAs.

[0009] It is thus an object of the present invention to provide for compounds or a composition comprising them for use in promoting microbiome benefit to skin. This microbiome benefit ensures that the skin is protected against undesirable bacteria. The present invention delivers the benefit by CFAs selectively affecting growth of non-commensal bacteria e.g., S. aureus whilst either promoting growth of or having no effect on growth of skin commensal bacteria like S. epidermidis.

[0010] Summary of the Invention

[0011] In a first aspect of the present invention relates to non-therapeutic use of conjugated fatty acids for microbiome benefit to skin, wherein the microbiome benefit is defined by inhibition of growth of non-commensal bacteria while growth or no change to commensal bacteria of skin.

[0012] In a second aspect, the present invention relates to non-therapeutic use of a personal care composition comprising: a. from 0.1 to 10 wt% conjugated fatty acids; and b. a cosmetically acceptable carrier; for microbiome benefit to skin. wherein the microbiome benefit is defined by inhibition of growth of non-commensal bacteria while growth or no change to commensal bacteria of skin. Detailed Description of the Invention

[0013] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word “comprising” is intended to mean “including” but not necessarily “consisting of” or “composed of.” In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims indicating amounts of material or conditions of reaction, physical properties of materials and / or use are to be understood as modified by the word “about”. Numerical ranges expressed in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and may be abbreviated as "wt%".

[0014] “Skin” as used herein is meant to include skin on any part of the body (e.g. face, neck, chest, back, arms, underarms, hands, legs, buttocks and scalp). It is especially useful for protecting the skin of babies. By babies is meant a child whose age is less than five years preferably less than three years more preferably less than a year. Such use against pathogens is preferably non- therapeutic, for example, delivered through a cosmetic or personal care composition. Preferably, a use, a composition and a method of the present invention is for non-therapeutic use. Any preference described hereinbelow with regard to one aspect of the invention (e.g. a use according to the present invention) is also preferred for use in any one of the other aspects of the invention.

[0015] The present invention relates to non-therapeutic use of conjugated fatty acids(CFA) e.g., conjugated linoleic acid (CLA) and conjugated linolenic acid (CLnA), for microbiome benefit to skin. The microbiome benefit is defined by inhibition of growth of non-commensal bacteria while growth or no change to commensal bacteria of skin.

[0016] Preferably, conjugated fatty acid is selected from CLA, CLnA and mixtures thereof. More preferably, CLA is selected as the CFA. CLA is known to provide benefits e.g., moisturization, antioxidant, anti-inflammatory, and boosting ceramide synthesis in skin cells. Conjugated linoleic acids are mixtures of positional and geometric isomers of polyunsaturated fatty acids with conjugated double bond. Isomers of conjugated linoleic acids include e.g. cis-9, trans-1 1 conjugated linoleic acid, trans-9, trans-1 1 conjugated linoleic acid and trans-10, cis-12 conjugated linoleic acid. Most preferred conjugated linoleic acid is cis-9, trans-11 conjugated linoleic acid. Preferably, the conjugated linoleic acid that may be used in the present invention is selected from cis-9, trans-1 1 conjugated linoleic acid and trans-10, cis- 12 conjugated linoleic acid and mixtures thereof. Preferably, if these two conjugated linoleic acids are used together, then, they may be used in 50:50 ratio.

[0017] By way of this benefit, the skin is protected against undesirable non-commensal bacteria. Preferably, the skin is protected against the non-commensal bacteria whilst either nourishing, i.e., promoting growth of skin commensal bacteria or leaving them un-affected. By the term ‘leaving them un-affected’ it is preferably meant that upon application of a CFA e.g., conjugated linoleic acid, no change in growth of skin commensals is observed. Preferably the non-commensal bacteria comprise at least one of E. coli, S. aureus, P. aeruginosa and P. acnes. Preferably the commensal bacteria comprise S. epidermis.

[0018] Further, the present invention relates to use of a personal care composition e.g. a skin care composition, comprising one or more conjugated fatty acids and a cosmetically acceptable carrier, for microbiome benefit.

[0019] Preferably, microbiome benefit as per this invention is achieved by way of selectively reducing growth of non-commensal bacteria like S. aureus. E. coli, S. aureus, P. aeruginosa, P. acnes, most preferably S. aureus. While it helps in growing or leaving unaffected to commensal bacteria, like S. epidermis.

[0020] Further, the present invention also relates to use of a personal care composition comprising one or more conjugated fatty acids and a cosmetically acceptable carrier, for microbiome benefit to skin.

[0021] A personal care composition as per the present invention (the composition) preferably comprises from 0.001 to 10 wt%, more preferably from 0.01 to 8 wt%, even more preferably from 0.1 to 6 wt% and furthermore preferably from 1 to 5 wt%, still more preferably from 2 to 4 wt% e. g 3 wt% of one or more conjugated fatty acids. An especially preferred aspect relates to use of the composition which comprises 0.2 to 10 wt% of conjugated fatty acids.

[0022] In a preferred aspect, the present invention relates to non-therapeutic use of a personal care composition comprising: a. 0.001 wt% to 10 wt% of one or more conjugated fatty acid; and b. a cosmetically acceptable carrier; wherein the composition comprises less than 1 wt%, preferably less than 0.1 wt% C10 to C18 fatty acid, for microbiome benefit to skin.

[0023] In yet another aspect, the present invention relates to a composition comprising: a. 0.001 wt% to 10 wt% of one or more conjugated fatty acids, b. a polyhydric alcohol; and c. a cosmetically acceptable carrier; wherein the composition comprises less than 1 wt%, preferably less than 0.1 wt% C10 to C14 fatty acid, for microbiome benefit.

[0024] As per any aspect of the present invention involving one or more conjugated fatty acids, the benefits may be obtained by use of a combination of oils rich in these fatty acids of esters thereof. When in use, a certain percentage say about 10% of the mixture of oils are hydrolysed to generate the desired unsaturated fatty acids to deliver the benefits of the invention. Suitable oils to be mixed are those rich in conjugated fatty acids include soybean oil, safflower oil, sunflower oil.

[0025] Preferably the inclusion of polyhydric alcohol e.g., glycerol, enhances the microbiome benefit by synergistically interacting with the conjugated fatty acids of the present invention. The polyhydric alcohol may be selected from one or more of glycerol, 1 ,3-butylene glycol, propylene glycol, 1 ,3- propanediol, pentylene glycol, hexylene glycol, and sorbitol. The most preferred polyhydric alcohol for inclusion in the composition of the invention is glycerol.

[0026] The skin commensal bacteria is preferably S. epidermidis. The skin is protected as per this invention from non-commensal bacteria which may be Escherichia. Coli (E. coli), Staphylococcus. Aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), Cutibacterium acnes (C. acnes; previously known as Propionibacterium acnes (P. acnes) or mixtures thereof. Consumers often find such non-commensal bacteria to be unwanted or undesirable as they may provide certain negative attributes like producing itchiness, discomfort or malodour. In certain cases, they may even be harmful or in extreme cases be pathogenic. Therefore, the non-commensal bacteria are preferably unwanted bacteria, undesirable bacteria, harmful bacteria and / or pathogenic bacteria or bacteria with a combination of these attributes.

[0027] The present invention thus provides for a composition for prevention of growth of non-commensal bacteria on skin. Model non-commensal bacteria which have been tested and observed to be inhibited include S. aureus.

[0028] The benefits disclosed and claimed in the use or the composition or the method of the present invention are to be understood to be due to the inclusion of the selective conjugated fatty acids. Such a composition could be in the form of a leave-on composition e.g. a cream, a lotion, a gel or a deodorant.

[0029] When the composition in accordance with the invention is a leave-on composition, it preferably comprises one or more of surfactant, emollient, humectant, pigment and preservative. They are most preferably produced for use in the form of a cream, a lotion, a gel or a deodorant.

[0030] The carrier acts as diluent or dispersant for the ingredients of the compositions. The carrier may be aqueous-based, anhydrous or an emulsion, whereby a water-in-oil or oil-in-water emulsion is generally preferred. If the use of water is desired, water typically makes up the balance of the composition, which most preferably is from 40 to 80 wt%. In addition to water, organic solvents may optionally be included as carrier to assist any other carrier in the compositions of the present invention. Examples include alkanols like ethyl and isopropyl alcohol. Other suitable organic solvents include ester oils like isopropyl myristate, cetyl myristate, 2 -octyldodecyl myristate, avocado oil, almond oil, olive oil and neopentylglycol dicaprate. Typically, such ester oils assist in emulsifying the compositions, and an effective amount is often used to yield a stable, and most preferably, water-in-oil emulsion.

[0031] Surfactants may also be present. When present, the total amount of surfactants is 2 to 40 wt%, and preferably from 4 to 20 wt%, optimally from 5 to 12 wt%. The surfactant is selected from the group consisting of anionic, nonionic, cationic and amphoteric actives. Particularly preferred nonionic surfactants are those with a C10-20 fatty alcohol or acid hydrophobe condensed with from 2 to 100 moles of ethylene oxide or propylene oxide per mole of hydrophobe; mono- and di- fatty acid esters of ethylene glycol; fatty acid monoglyceride; sorbitan, mono- and di- C8-C20 fatty acids; block copolymers (ethylene oxide / propylene oxide); and polyoxyethylene sorbitan as well as combinations thereof. Alkyl polyglycosides and saccharide fatty amides (e.g. methyl gluconamides) are also suitable nonionic surfactants. Preferred anionic surfactants include soap, alkyl ether sulfate and sulfonates, alkyl sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyl sulfosuccinates, C8to 20 acyl isethionates, acyl glutamates, C8to 20 alkyl ether phosphates and combinations thereof.

[0032] Emollients may also be used, if desired, as a carrier. Alcohols like 1 -hexadecanol (i.e. cetyl alcohol) are preferred. Other emollients include silicone oils and synthetic esters. Silicone oils suitable for use include cyclic or linear polydimethylsiloxanes containing from 3 to 9, preferably from 4 to 5 silicon atoms. Non-volatile silicone oils useful as emollients include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers. The non-volatile polyalkyl siloxanes useful polydimethylsiloxanes. Silicone elastomers may also be used. The ester emollients that may optionally be used are:

[0033] (i) alkenyl or alkyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include isoarachidyl neopentanoate, isononyl isonanonoate, oleyl myristate, oleyl stearate, and oleyl oleate;

[0034] (ii) ether-esters such as fatty acid esters of ethoxylated fatty alcohols;

[0035] (iii) polyhydric alcohol esters. Ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200- 6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl mono-stearate, 1 ,3-butylene glycol monostearate, 1 ,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters;

[0036] (iv) wax esters such as beeswax, spermaceti, stearyl stearate and arachidyl behenate; and,

[0037] (v) sterols esters, of which cholesterol fatty acid esters are examples.

[0038] Emollients, when present, typically make up from 0.1 to 50 % by weight of the composition, including all ranges subsumed therein.

[0039] Preferably, if the leave-on composition is in the form of a cream, e.g. a vanishing cream, then it comprises one or more saturated fatty acids having carbon chain length from C10 to C20 such as lauric acid, myristic acid, palmitic acid and stearic acid. Often, the saturated fatty acids may be a mixture of palmitic acid and stearic acid commercially available as hystric acid. Such fatty acids may preferably be present in an amount from 3 to 25 wt%, more preferably from 5 to 20 wt%, even more preferably from 6 to 18 wt%, still more preferably from 8 to 16 wt% and yet more preferably from 10 to 14 wt% of one or more saturated fatty acids. Such vanishing creams preferably further comprise soap of corresponding fatty acids preferably formed in-situ due to inclusion of alkalis e.g. sodium hydroxide and potassium hydroxide. Such soap, formed in-situ, is preferably in an amount from 0.1 to 10 wt%, more preferably from 1 to 8 wt%, even more preferably from 3 to 5 wt%. By ‘vanishing cream’, it is preferably meant that the composition upon application on to the skin, vanishes without leaving any visible streaks behind.

[0040] Moisturisation may be improved through use of petrolatum or paraffin. Thickeners may also be utilized as a portion of the carrier in the compositions. Typical thickeners include cross-linked acrylates (e.g. Carbopol® 982), hydrophobically-modified acrylates (e.g. Carbopol®1382), cellulosic derivatives and natural gums. Among useful cellulosic derivatives are sodium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, ethyl cellulose and hydroxymethyl cellulose. Natural gums suitable for the present invention include guar, xanthan, sclerotium, carrageenan, pectin and combinations of these gums. Amounts of the thickener may range from 0.001 to 5 wt%, optimally from 0.01 to 0.5 wt%.

[0041] Various other ingredients may also be used in compositions. Actives are defined as skin benefit agents other than emollients and other than ingredients that merely improve the physical characteristics of the composition. Although not limited to this category, general examples include extender pigments such as talcs and silicas, as well as alpha- hydroxy acids, beta-hydroxy acids and zinc salts. Beta-hydroxy acids include salicylic acid. Zinc oxide and zinc pyrithione are examples of useful zinc salts.

[0042] Suitable preservatives include alkyl esters of p-hydroxybenzoic acid, hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Particularly preferred preservatives are methyl paraben, propyl paraben, phenoxyethanol and benzyl alcohol. Preservatives are preferably used in amounts from 0.1 to 2 wt%.

[0043] Alternatively, when the composition of the invention is delivered as product of use in the underarm it may be delivered using a cosmetically acceptable carrier that is usually used to deliver deodorant or antiperspirant products. The cosmetically acceptable carrier is preferably selected from the group consisting of hydrophobic carrier, carrier liquid, emulsion or an anhydrous base. An especially preferred form of a product which is delivered as a deodorant or an antiperspirant format involves a cosmetically acceptable base which is anhydrous. Such anhydrous compositions are useful for deodorant products especially for application in the underarm region. The composition comprises a topically acceptable base which is preferably anhydrous. By an anhydrous base, preferably, it is meant that water content in the composition is less than 5 weight percent, preferably less than 2 weight percent, more preferably less than 1 weight percent and optimally absent from the composition. To enable this, the anhydrous base preferably comprises a silicone compound, a polyhydric alcohol or a wax.

[0044] The packaging could be a patch, bottle, tube, roll-ball applicator, propellant driven aerosol device, squeeze container or lidded jar.

[0045] The pH of a leave-on composition as per the present invention is preferably in the range from 4 to 9, more preferably in the range from 4.5 to 8 and even more preferably in the range from 5 to 7.5.

[0046] This invention is especially useful for use on skin of babies where the use of broad -spectrum antibacterial agents is considered as too harsh as it tends to interfere with the growth and maintenance of a healthy skin microbiome for long term health of the babies as they grow into adults. It is well accepted that baby skin barrier is more vulnerable than adult skin. Baby skin barrier is more delicate and water loss from the surface is faster than in adult skin. Similarly, the microbiome of baby skin is seen to be different from that of adult skin. Soon after birth, the baby’s skin as well as skin microbiome continues to change for up to about three to five years. Together with the barrier function, the microbiome plays a critical role in skin’s natural defence. It is thus imperative that the skin microbiome of babies and infants should be nourished to allow for its natural growth and maturation thereby maintaining optimum skin health.

[0047] Thus, whether used on skin of babies or others, the composition for use in the present invention is preferably, substantially free of a conventional antimicrobial compound. By ‘substantially free’ it is meant that conventional antimicrobial actives are present in less than 0.1 wt%, more preferably less than 0.05 wt%, furthermore preferably less than 0.01 wt%, even furthermore preferably less than 0.001% by weight of the composition. By ‘conventional antimicrobial actives’, it is meant that an antimicrobial active which kills or inhibits bacteria which attack skin like E. coli, S. aureus, P. aeruginosa, or P. acnes among others. Preservatives which are included in compositions for their microbial stability are excluded from the definitions of antimicrobial actives mentioned above. Preservatives are included to ensure that the compositions are stable with respect to microorganisms which may grow and degrade the compositions. On the other hand, antibacterial compounds are included in compositions to hinder the growth of microorganisms which are present on the substrate (e.g. skin) on which the compositions are applied. Conventional antimicrobial compounds are generally those from the class of biguanides, bisphenols, halophenols, oligodynamic metal compounds like those of silver or zinc, cationic antimicrobial compounds. Biguanide has a general base structure which may be further derivatised e.g., chlorhexidine or polyhexamethylene biguanide (PHMB). Bisphenols include triclosan or hexachlorophene. Halophenol include chloroxylenol (PCMX). Cationic antimicrobial compounds include benzalkonium chloride, cetyl pyridinium chloride or cetyl trimethyl ammonium bromide.

[0048] The class of low boiling alcohols (which are fast acting antimicrobials) are especially not included in any substantial amount in the composition of the invention. Ideally, they are absent from such compositions. By ‘low boiling alcohols’, it is meant that monohydric alcohols with 2 to 5 carbon atoms.

[0049] When the composition of the invention is formulated for use on skin of babies, it is preferred that it is substantially free of a fragrance component. By a fragrance component is meant a molecule or a group of molecules that are compounded to form a perfume. The characteristic of such compounds is that they are volatile (to varying degrees) and offer a pleasant odour. In the context of perfumes or fragrance component, “by substantially free” is meant that that they are present in less than 0.05 wt%, more preferably less than 0.01 wt%, furthermore preferably less than 0.005 wt%, even furthermore preferably less than 0.001 wt%.

[0050] Alternatively, and equally preferably the composition may be in the form of a wash-off composition (alternatively called as a cleansing composition) for delivering selective protective benefit to topical areas e.g. skin and / or hair of mammals, especially humans. Such wash-off format is enabled by including preferably from 0.25 to 80 wt% surfactant in the composition. Such a composition includes any product applied to a human body for also improving appearance, cleansing, or general aesthetics. The composition of the present invention may be delivered with a topically acceptable carrier. Example of such wash-off compositions include a shampoo, a bodywash, a handwash.

[0051] In general, the surfactants may be chosen from the surfactants described in well-known textbooks like "Surface Acti ve Agents" Vol. 1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, and / or the current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in “ Tenside-Taschenbuch" , H. Stache, 2nd Edn., Carl Hauser Verlag, 1981. Any type of surfactant, i.e., anionic, cationic, nonionic, zwitterionic or amphoteric, can be used but preferred surfactant is of the anionic, amphoteric, or non-ionic type, most preferably of the anionic and amphoteric type.

[0052] The surfactant may be a soap. Soap is a suitable surfactant for personal washing applications of composition of the invention. The soap is preferably C8-C24 soap, more preferably C10-C20 soap and most preferably C12-C16 soap. Preferably, the soap is formed of a salt of saturated fatty acids. Alternatively, the soap may be formed of unsaturated fatty acids other than the conjugated fatty acids of the present invention. The cation of the soap may be alkali metal, alkaline earth metal or ammonium. Preferably, the cation of the soap is selected from sodium, potassium or ammonium. More preferably the cation of the soap is sodium or potassium. The soap may be obtained by saponifying a fat and / or a fatty acid. The fats or oils generally used in soap manufacture may be such as tallow, tallow stearines, palm oil, palm stearines, soya bean oil, fish oil, castor oil, rice bran oil, sunflower oil, coconut oil, babassu oil, palm kernel oil, and others. In the above process the fatty acids are derived from oils / fats selected from coconut, rice bran, groundnut, tallow, palm, palm kernel, cotton seed, soyabean, castor etc. A typical fatty acid blend consisted of 5 to 30% coconut fatty acids and 70 to 95% fatty acids ex hardened rice bran oil. Fatty acids derived from other suitable oils / fats such as groundnut, soybean, tallow, palm, palm kernel, etc. may also be used in other desired proportions. The most preferred soap is a laurate soap. The soap, when present in solid forms of the present invention is present in an amount of 30 to 90 wt%, preferably from 50 to 85 wt%, more preferably 55 to 75 wt%. The soap, when present in liquid forms of the composition is present in 0.5 to 20 wt%, preferably from 1 to 10 wt% by weight of the composition.

[0053] Alternatively, the surfactants are non-ionic surfactants, such as C8-C22, preferably C8-C16 fatty alcohol ethoxylates, comprising between 1 and 8 ethylene oxide the surfactants are preferably selected from primary alkyl sulphate, secondary alkyl sulphonates, alkyl benzene sulphonates, or ethoxylated alkyl sulphates. The composition may further comprise an anionic surfactant, such as alkyl ether sulphate preferably those having between 1 and 3 ethylene oxide groups, either from natural or synthetic source and / or sulphonic acid. Especially preferred are sodium lauryl ether sulphates. Alkyl polyglucoside may also be present in the composition, preferably those having a carbon chain length between C6 and C16. Suitable nonionic surfactant concentrations in liquid forms of cleaning application are generally more than 0.5 but less than 10 wt%, preferably from 1 to 5 wt%. In solid compositions, the nonionic surfactant is preferably present in 5 to 40 wt%, preferably from 10 to 30 wt%.

[0054] The cleansing composition of the invention may also be delivered through a moisturizing bar or a moisturizing liquid composition. Moisturizing bar compositions comprising fatty acyl isethionates (e.g., cocoyl isethionate) are especially preferred. Fatty acyl isethionates (e.g., cocoyl isethionates) surfactant "products" are defined as mixtures of anionic acyl isethionate surfactants and fatty acids / fatty acid soaps. They are highly desirable in personal care skin or hair cleansing products, particularly in personal care products, because they lather well, are mild to the skin and have good emollient properties. Typically, fatty acid isethionate surfactant products are produced by esterification of fatty acids or by reaction of fatty acid chloride having carbon chain length of C8 to C20 with isethionate. A typical surfactant product containing fatty acyl isethionate contains about 40 to 95 wt% acid isethionate, and 5 to 50 wt%, typically 10 to 40 wt% free fatty acid, in addition to isethionate salts, typically at less than 5 wt%, and trace (less than 2 wt%) of other additives. Fatty acid soap may be included in the range of 5 to 15 wt%. Other surfactants like betaines may be included in 1 to 5 wt%. Water is generally included in 2 to 8 wt% of the composition.

[0055] It is desirable to formulate compositions which have relatively mild surfactants. One combination of surfactants which is particularly desirable is combination of alkyl isethionate (e.g., fatty acid esters of isethionate acid such as sodium lauroyl or sodium cocoyl isethionate) and alkyl taurate (e.g., alkyl taurate amides such as N-methyl taurate). Alternatively, the compositions could also be formulated with taurates alone in the absence of isthionates. Surfactant mixtures have the advantage that they are sulfate-free. Further, they offer the ability to formulate isotropic systems at neutral and slightly acidic pH. Thus, they allow the use of more skin friendly preservation systems.

[0056] Water may preferably be present in 10 to 90 wt% depending on the format of the composition. In solid composition water may be present in 10 to 30 wt%, while in liquid or semi-solid composition, water may be present in 40 to 90 wt%.

[0057] The pH of a wash-off composition as per the present invention is in the range of 5 to 11 , preferably in the range of 5.5 to 10, more preferably in the range of 5.5 to 9 and even more preferably in the range of 5.5 to 8. Though the use according to the invention generally is of a non -therapeutic nature, the composition may also be used in therapeutic applications. In such cases, the use according to the invention may be in the treatment of skin conditions like eczema, atopic dermatitis, seborrheic dermatitis, acne, and dandruff.

[0058] Thus, the present invention delivers microbiome benefit to skin through conjugated fatty acids selectively affecting growth of pathogens e.g., S. aureus whilst either promoting growth of; or having no effect on, growth of skin commensal bacteria like S. epidermidis.

[0059] The invention will now be demonstrated with the help of the following non-limiting examples.

[0060] Example A and 1 to 3: Use of conjugated linoleic acid for obtaining microbiome benefit:

[0061] Use of conjugated fatty acid e.g., conjugated linoleic acid, in obtaining microbiome benefit was studied using the examples described below.

[0062] Experiments were carried out on the growth of S. Epidermidis (ATCC 12228) and S. aureus (ATCC 6538) in the presence of various conjugated fatty acids fatty acids using the following procedure. These bacteria were sourced from Hi-Media.

[0063] Fatty acid Stock preparation

[0064] Conjugated linoleic acid (100 mg / mL; catalogue number: 04397; Sigma) was obtained. In the examples shown in table 1 below, trans-10, cis-12 conjugated linoleic acid was used. Whereas, in examples shown in table 2 below, cis-9, trans-1 1 conjugated linoleic acid (100 mg / mL; catalogue number: 16413; Sigma) was used.

[0065] Assay Protocol

[0066] Day 1

[0067] The microorganism (S. epidermidis or S. aureus as the case may be) was streaked on trypticase soy agar (TSA) plates and incubated at 37°C for 24 h.

[0068] Day 2

[0069] Plate cultures of the microorganism were used to set up 0.3 OD 620 nm (corresponding to log 108CFU / mL) in 1 X PBS (pH 7.4). The test samples (200 JLLL) were added to 96 well plate, followed by addition of above set cultures (20 p.L). The 96 well plate was placed in a Tecan reader and absorbance was read at 620 nm for a period of 24 to 30 h with a kinetic interval of 1 h. The values obtained were plotted as a growth curve with X axis representing time (in hour, h) and Y axis as absorbance read at 620nm. The data on the % / fold increase over control at the end of 24 to 30 h is shown in the table 1 below.

[0070] After incubation the control and test samples were enumerated by serially diluting and plating using tryptone yeast extract agar plates. The plates were incubated at 37°C for 48 h. Post incubation, the colonies were counted and recorded as log CFU / mL.

[0071] Table 1

[0072] *T rans-10, cis- 12 conjugated linoleic acid

[0073] Table 2

[0074] #Cis-9, trans-11 conjugated linoleic acid,Ano significant change in the count.

Claims

Claims1 . Non-therapeutic use of conjugated fatty acids for microbiome benefit to skin, wherein the microbiome benefit is defined by inhibition of growth of non-commensal bacteria while growth or no change to commensal bacteria of skin.

2. Use of fatty acid as claimed in claim 1 wherein the conjugated fatty acid is selected from conjugated linoleic acid, conjugated linolenic acid and mixtures thereof.

3. Use of fatty acids as claimed in claim 1 wherein the conjugated fatty acid is conjugated linoleic acid.

4. Use of fatty acid as claimed in claim 3 wherein the conjugated linoleic acid is Cis-9, trans- 11 conjugated linoleic acid.

5. Use of fatty acid as claimed in any one of claims 1 to 4 wherein the non-commensal bacteria comprises at least one of E. coli, S. aureus, P. aeruginosa and P. acnes.

6. Use of fatty acid as claimed in claim 5 wherein the non-commensal bacteria is S. aureus.

7. Use of fatty acid as claimed in any one of claims 1 to 6 wherein the commensal bacteria comprise S. epidermis.

8. Non-therapeutic use of a personal care composition comprising: a. from 0.001 to 10 wt% one or more conjugated fatty acid; and b. a cosmetically acceptable carrier; for microbiome benefit to skin. wherein the microbiome benefit is defined by inhibition of growth of non-commensal bacteria while growth or no change to commensal bacteria of skin.

9. Use of the composition as claimed in claim 8 wherein composition further comprises a polyol; for microbiome benefit to skin.

10. Use of the composition as claimed in claim 9 wherein the polyol is glycerol, for microbiome benefit.

11. Use of the composition as claimed in any one of claims 8 to 10 wherein the microbiome benefit is achieved by way of selectively reducing growth of skin non-commensal bacteria like S. aureus while growing or no change in skin commensal bacteria like S. epidermis.

12. Use of the composition as claimed in any one of claims 8 to 11 wherein the composition is a leave-on product in the form of a cream, a lotion, a gel or a deodorant.

13. Use of the composition as claimed in any one of claims 7 to 11 wherein the composition is a wash-off product in the form of a shampoo, a bodywash, a handwash further comprising 0.25 to 80 wt% surfactant, for microbiome benefit.

14. Use of the composition as claimed in claim 13 wherein the surfactant in the composition is selected from a synthetic anionic, an amphoteric surfactant and mixtures thereof.

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