The skin microbiome plays a key role in skin health and disease. While imbalances in the composition of the skin microbiome have been linked to disease, studying the microbiome has been challenging due to limited methods for co-culturing multiple bacterial species. Now, scientists have developed a new medium that enables the co-cultivation of important skin bacteria while maintaining their natural balance, opening new avenues for studying microbial interactions and skin health.
Development of Cosmetics and Drugs for Numerous Skin Diseases
Human skin harbors a great diversity of bacteria. The composition of the bacterial community – the so-called “skin microbiota” – has a significant impact on skin health. A healthy balance between the different types of bacteria on the skin often means healthy skin. The loss of this balanced skin microbiota can lead to diseases such as atopic dermatitis, acne and psoriasis. As the skin microbiota can vary depending on an individual’s age, gender, climate and occupation, understanding its composition is crucial for identifying bacteria that cause skin diseases and for targeting these bacteria for treatment.
Culturing the skin microbiota in the laboratory can be difficult for a number of reasons, including the difficulty of replicating the unique environment of the skin and the lack of effective cultivation methods. In a recent study published in the journal Alternatives to Animal Testing and Experimentation, researchers addressed the limitations of culturing skin microbiota by developing a novel culture system that enables the cultivation of different skin bacterial species in the laboratory.
Researchers led by Associate Professor Yuuki Furuyama of Tokyo University of Science, lead investigator of the study, have developed the first complex culture system that can cultivate multiple indigenous skin bacteria in a balanced state. A detailed analysis of the biology of indigenous skin bacteria that affect the condition of human skin is now possible. In the future, the system can be used in the research and development of cosmetics and medicines for numerous skin diseases.
New Medium Enables Joint Cultivation of Important Skin Bacteria
As it is difficult to culture the skin microbiota in the laboratory, researchers have traditionally used metagenomic analysis for their study – an approach in which the combined genome of all bacteria in a community is extracted. While metagenomic analysis can provide useful insights, it may not be suitable for uncovering the interactions between different species.
The newly created growth medium called “TUS Skin Bacteria Co-culture (TSBC)” medium may allow researchers to co-culture multiple bacteria and study their interactions. In the study, the researchers successfully cultured four skin bacteria, namely Staphylococcus epidermidis, Staphylococcus capitis, Cutibacterium acnes and Corynebacterium tuberculostearicum. They found that the bacterial composition of the laboratory-grown community was balanced and similar to the bacteria found in Japanese skin.
Research on the indigenous skin microbiota has mainly focused on metagenomic analyses, which do not involve culture methods, or on analyzing individual bacteria in pure culture. However, since multiple bacteria interact with each other in the actual skin environment, the researchers felt the need for a model culture system that reproduces the interaction relationships.
Tailored, Preventative Solutions to Promote Healthier, More Resilient Skin
The skin microbiota is highly individualized and can even vary between different areas of the skin of the same person. Skin characteristics such as sebum content, moisture and dryness influence the composition of the microbiota. This new co-culture technique opens up opportunities to investigate how internal and external factors, including skin care products, influence the microbiota at different skin sites. In addition, future research can investigate how skin care routines affect the microbiota of different ethnicities and skin types.
As skin sensitivities and conditions such as eczema continue to rise due to factors such as climate change and environmental stress, a more holistic understanding of the imbalance of the skin’s microbiota offers a pathway to new treatment options. By targeting the microbiota, researchers may be able to develop customized, preventative solutions that promote healthier, more resilient skin, improving the quality of life for millions of people around the world.