A multitude of different bacteria reside on the human skin surface, some of which must be considered harmful since they can cause skin diseases such as acne (known as “pathogenic bacteria”). Other skin microbes, in turn, provide a positive action (known as “saprophytic bacteria”), as growth of these is able to inhibit the reproduction of harmful bacteria, and as a result they exert a protective function on the skin. It is therefore desirable to influence the skin flora to the effect that the growth of pathogenic bacteria is reduced, and the growth of saprophytic bacteria is favored.
Cosmetic cleansing agents usually include surfactants and/or surfactant combinations, which due to the irritating effect can adversely influence the skin flora and are therefore not recommended for use on blemished skin and/or skin suffering from acne. In the case of soaps, additionally the alkaline pH value can adversely influence the skin, which may worsen the skin complexion, especially in the case of skin imperfections.
DE 102009002262 already disclosed the use of prebiotically active surfactant combinations, in particular in washing and cleaning agents for hard surfaces. For cosmetic use on particularly sensitive parts of the skin, such as the facial skin, or for cosmetic use on diseased skin, however, milder compositions are desirable, which not only promote the growth and/or the viability of saprophytic bacteria of the skin flora as compared to the growth and/or the viability of pathogenic bacteria of the skin flora selectively at the application site (of the skin), but also ensure gentle cleansing of the skin and outstanding skin care.
It is therefore desirable to find substances or substance mixtures that exhibit a prebiotic action on the skin or in the skin flora and that are suitable for use in mild, nourishing skin cleansing preparations.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.