Use of probiotic lactic acid bacteria for balancing the skin's immune system

#The present invention pertains to the use of probiotics for the preparation of a carrier for balancing the skin's immune function. In particular, the present invention pertains to the use of probiotic micro-organisms for improving the skin's immune function under stress conditions, leading to immune suppression, specifically for normalizing the skin's immune activity and reducing the tendency to develop hyper-reactions under such conditions.

#The continuous decrease of the atmosphere's ozone layer with the concurrent increase of ultraviolet radiation reaching the planet's surface has attracted a great deal of interest in its potential consequence on human health. Although exposure to ultraviolet radiation is needed for humans to produce vitamin D, growing evidence suggests that extensive exposure to sun-light, in particular to ultraviolet radiation, causes a variety of problems in the skin, including induction of certain skin cancers and induction of accelerated skin ageing (photoageing).

#It is presently hypothesized that the primary factor of generating skin cancer is a mutational damage in the DNA of the generative cells in the skin caused by ultraviolet radiation while UV-light induced injury to the skin's immune system obviously seems to supply a second factor necessary for the further development thereof In a healthy system early malignant cells are eliminated by the normal functioning of the skin's immune system. Yet, upon ultraviolet radiation the skin's immune system seems to undergo suppression and cannot perform its usual surveillance function any more. As a consequence very early skin cancer cells are not eliminated, which situation will eventually lead to the malignant cells to escape the immune system and develop to tumours.

#In the figures,

#FIG. 1 shows the inflammatory reaction associated with a contact hypersensitivity reaction in the various mice models examined as determined by ear swelling;

#FIG. 2 shows the results obtained with an antibody against ICAM-1 in the various animal models indicating;

#The present invention provides for the first time that the gut flora composition may also have a beneficial effect on certain protective functions in regions of the bodies distant from the location at which the probiotic micro-organisms colonize the individual, namely the skin. Further, it has been shown that the probiotics may control in the skin divergent processes such as up-regulating the immune system during an immunosuppressive condition and at the same time down- regulating hyper-reactions, such as inflammatory or allergic reaction, such as eczema or atopic dermatitis. This holds especially true for elderly individuals, who normally have a reduced immunocapacity.

#According to a preferred embodiment the probiotics to be included into the carrier are selected from the group consisting of Lactic acid bacteria, in particular Lactobacilli and/or Bifidobacteria and are more preferably Lactobacillus johnsonii, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus paracasei, Lactobacillus casei or Bifidobacterium bifidum, B. breve, B. animalis, B. infantis, B. dolescentis B. pseudocatenulatum. Since due to their distinct oxygen requirement Lactobacilli and Bifidobacteria colonize the gut at different locations a mixture thereof may be used so as to provide a broad coverage.

#According to a most preferred embodiment, the strains used are Lactobacillus johnsonii (La1) and Lactobacillus paracasei (ST11) deposited under the Budapest Treaty with the Institute Pasteur (28 rue du Docteur Roux, F-75724 Paris Cedex 15, France) on Jun. 30, 1992 and Jan. 12. 1999, respectively, under the deposit no. CNCM I-1225 and the deposit no. CNCM I-2116, respectively.