Analysis of the impact of cosmetic products on the protection and repair of skin microbiota
For skin microbiota studies on a panel of volunteers, several approaches are possible in order to identify different effects (or the absence of effects) of a finished product or an ingredient.
One of these approaches is based on a precise protocol allowing to analyze the impact of a formula on the protection of the microbiota balance of each volunteer, and on its capacity to restore this initial balance specific to each one.
This procedure makes it possible to obtain relevant and interpretable results regarding the action of the cosmetic product on the microbial ecosystem, based on the initial balance of each volunteer, by disturbing this balance in a controlled manner, and by analyzing the conditions of return to it.

During the microbiota imbalance phase, the interest is to identify whether the product can reduce the variations in the microbial population induced by repeated and intensive washings. This analysis makes it possible to determine which microbial populations have been “protected” by the application of the product on the skin.
This procedure of successive washes can be replaced by another controlled method that would also lead to a dysbiosis of the skin flora.
During the second phase, which consists of allowing the balance of the microbiota to be restored, the objective is to see to what extent the application of the product allows a more rapid and effective return to the initial balance, compared to an area not treated by the product.
This model thus makes it possible to conclude as to the protective effect of a formula in any context that would induce an imbalance of the initial ecosystem, and as to the repairing effect of the microbiota thanks to the application of the product.