Dr Bernhard Paetzold, Co-founder of S-Biomedic, discusses the 2019 ‘Skin microbiome modulation induced by probiotic solutions’ study published in Microbiome. Specifically, this article reviews the potential for probiotic skincare as a means of modulating the skin microbiome as a solution to skin conditions such as acne.
Live bacteria in personal care
The use of live bacteria to treat diseases dates back more than 3,000 years. Ancient Indian texts reveal cow dung was recommended to treat multiple stomach disorders. Similarly, Chinese medical literature shows faecal matter was used to treat severe diarrhoea in the 4th century.
Nowadays, the technique has evolved but the same principle applies to faecal microbiota transplants. In other words, the transfer of faecal bacteria and other microbes from a healthy ‘donor’ to another individual. They are most commonly used to treat intestinal infections by the antibiotic-resistant bacterium Clostridium difficile.
With an uptick in research around the skin microbiome, we know that the skin hosts a diverse mix of microorganisms. We also know that alterations in this microbiome are closely linked to common skin-associated diseases, including acne, psoriasis, and eczema amongst others.
So, what if the same thinking behind faecal transplants applies to the skin microbiome?
Modulating the skin microbiome
In 2019, I, along with other researchers from S-Biomedic and those from Universitat Pompeu Fabra (UPF), set out to explore just that.
We used mixtures of different skin microbiome components from donor microbiomes to see if we could modify the skin microbiome composition in recipients. Different Cutibacterium acnes bacterial strain combinations were used and applied sequentially to 8 defined areas of the skin of 18 healthy volunteers over a 3-day period.
C. acnes is of particular interest. It was selected for use as it is a prominent component of the natural skin flora. It also has significant strain diversity with certain strains linked to a variety of skin conditions – including acne vulgaris (acne) while some others are mostly present on healthy people with balanced skin
We were able to demonstrate that modifying the composition of the skin microbiome through the application of donor bacteria is indeed possible. Repeated application of donor microbiomes resulted in the recipient microbiomes adopting a similar composition to that of the donor, without any adverse effects.
Despite allowing the volunteers to shower and take part in sports activities, evidence of bacteria having been transplanted into skin microbiomes was seen well beyond the application days. The results were, however, temporary and the skin microbiomes of study participants reverted to their original composition after a few weeks.
Notably, some microbial mixtures were instilled into the skin microbiomes of recipients more than others and not all individuals responded in the same manner to applications of the same strain combinations. This suggests recipient microbiome make up also determines success of this method.
We also found that the dose of the microbial mixtures used played an important part in changing the skin microbiome. Where skin microbiome changes were observed, higher doses extended the length of time in which the applied strain persisted on the skin.
Other studies have already shown that applying live bacteria to the skin can decrease skin pH and improve moisture retention.
Developing new therapeutic solutions
Now, our findings have provided the next step in skin microbiome research. By showing it is possible to modify the composition of the skin microbiome, our same methods can be applied to research to change the microbiome from a disease state to a healthy one.
This has a wide range of potential applications to discover new natural therapies and daily cosmetics for bacteria-associated skin disorders. From industry professionals and consumers alike, the promise of probiotic skin care solutions has vast potential for skincare products – whether for healthy or specific skin conditions like sensitive skin.