Modulation of skin microbiota by topical prebiotics
Recent scientific and technological developments provide a more insightful knowledge of the human microbiome in different body areas, such as skin. A diverse and balanced microbiota is usually related with healthier skin. Disruption of microbial populations can be linked to disease. Atopic dermatitis, acne vulgaris and psoriasis are some examples of cutaneous pathologic states where dysbiosis may have a physiopathologic impact. An unbalanced microbiome may increase the risk of disease, as well as play a role in disease progress and response to treatment. It is therefore important to understand the microbiological ecosystem of the skin, the interactions between microbiome and the immune system. Maybe it is possible to promote skin health, prevent or treat disease by modulating such populations or their interactions. Possible strategies to achieve this include the topical route, either by means of prebiotics or probiotics. The latter, as they are viable organisms, are extremely difficult to incorporate into a topical formulae. Prebiotic ingredients, on the other hand, are more easily integrated into creams, lotions, and other skin products, and a few are already on the market. Many more are expected in the near future. In this review, the authors look at the scientific rationale behind the use of these agents and present a review the scientific literature, as well as selected studies made public by commercial manufacturers.
In recent years, as a result of new insight deriving from molecular DNA sequencing methodologies, such as 16S rRNA-Gene, and projects like the Human Microbiome Project and MetaHIT, the human microbiome gained a renewed interest. Fuelled by this interest and under the hat of "human health promoters" the development and marketing of prebiotics and probiotics skyrocketed and a proof of this is the fourfold increase in the number of published studies on microbiome-related subjects seen between 2005 and 2012.
Most of these studies have been focused on the field of nutrition, oral supplementation and colon diseases or dysfunctions. However, as more and more information about human microbiome is unveiled and we began to understand the impact of thi