Research on the skin microbiome is a fascinating and trendy topic and will probably evolve further. However, despite the intense research, the microbiome shows huge inter- and intra-individual variation and there has been until now no scientific consensus on its perfect composition. 


An aspect that still needs more research effort is the influence of cosmetic products on the resident microbiome. What is happening in the microbiome realm when applying oily formulations on skin areas that by nature do not have high sebum production and feature an adapted healthy microbiome? How can we ensure that added microorganisms will survive in the microbial communities on the skin surface? 


And might it be possible that the wellmeant application of probiotic products might have an adverse effect on the skin microbiome, destroying the adapted balance by adding more species of certain bacteria?


The findings that the skin microbiome is essential for skin health pose a challenge to cosmetic industry to develop new products that not only consider traditional skin types such as oily or dry but to widen their understanding of skin types to certain microbiome types. 


Since the claim behind using formulations modifying, enhancing or feeding the microbiome, is the improvement of skin health and especially the strengthening of the skin barrier function, traditional biophysical testing methods and imaging are well-suited to substantiate health-related claims of such products.