Evonik unveils new skin microbiome model for enhanced cosmetic ingredient testing

Evonik develops a skin microbiome model, enabling more accurate laboratory testing of cosmetic ingredients and their impact on microbial communities. Personal Care Insights talks to Stefan Pelzer, head of microbiome research at Evonik, to learn how the model replicates realistic skin conditions and marks an advancement in evaluating microbiome interactions.

The development allows cosmetic brands to make scientifically substantiated claims about microbiome-friendly products, addressing growing consumer demand for efficacy data. The chemicals company is also developing models for acne-prone skin and exploring further enhancements in collaboration with industry partners.

Its new model co-cultivates eight to ten skin microbes, allowing for an analysis of their interactions in a controlled environment. This approach bridges the gap between simpler in-vitro tests and more complex in-vivo studies, providing formulators with precise data on how ingredients affect skin microbiota. The company is also advancing its research by integrating microbial cultures with skin tissue models, aiming to create more comprehensive testing methods in the future.

Could you elaborate on R&D at Evonik, particularly in relation to the skin microbiome?
Pelzer: There is a lack of methodological consensus, making it difficult for participants in the personal care industry to evaluate microbiome-friendliness claims for skin care products. Evonik introduced a skin microbiome lab model called SkinMicrobes, containing eight of the most prominent inhabitants of human skin simultaneously. With this model, we can scientifically analyze the impact of cosmetic ingredients and formulations on the growth kinetics and community diversity of skin microbiome representatives. Our co-culture model mimics the interaction of strains within a skin ecosystem, providing a scientific basis to evaluate microbiome interactions such as microbiome-friendly, promoting, modulating or impairing of cosmetic ingredients. With SkinMicrobes, we now have access to an efficient, high-throughput method to bridge the gap between simple compatibility tests with individual bacterial strains and complex tests on human subjects.

How does the innovation align with consumer trends and demands for microbiome-friendly products?
Pelzer: Consumers want cosmetic products that are in balance with nature and that includes the skin microbiome. Accordingly, over the past few years, we’ve observed a steady increase in product launches related to the skin microbiome. The demand for microbiome-friendly cosmetics is expected to grow, making it a key area for cosmetic ingredient suppliers. As a science-driven company, our goal is to establish a scientific foundation for developing the microbiome-friendly ingredients we offer. Our existing and future predictive models for specific skin conditions are fundamental in determining the microbiome interaction of ingredients and formulations. We can now focus our internal development on ingredients and formulations that respect or even promote the skin microbiome, supported by scientific data.

How do the new microbiome-focused developments contribute to sustainability?
Pelzer: Scientifically proven ingredients that are microbiome-friendly, balancing, or promoting will enhance the resilience of our skin microbiome and prevent shifts toward imbalance, which are often linked to undesirable skin conditions. Having said this, microbiome friendliness is, of course, only one dimension to consider when developing modern cosmetic ingredients. Having eco-friendliness in mind, we designed our Ecohance program, which embeds sustainability into the core of cosmetic ingredients and ensures that every product is a testament to the more efficient use of resources. We see alternative feedstocks as a big lever to minimize environmental impact while traceable supply chains allow for the fair integration of communities. Stefan Pelzer, head of microbiome research at Evonik.

What are the potential benefits of microbiome-friendly ingredients for formulators and brands looking to create differentiated products on the market?
Pelzer: Our microbiome-friendly and interaction claims are scientifically sound and our customers can rely on them. However, we’ve learned that formulation can also influence microbiome interaction. Therefore, close collaboration with our customers in ingredient and formulation development is essential to ensure that the entire product stands out in the market regarding microbiome interaction statements.

What challenges did you face during the development of the microbiome innovation?
Pelzer: In the development of SkinMicrobes, we encountered several technological challenges, as establishing a predictive skin microbiome model that simulates normal skin conditions is inherently complex. We believe that any model depends on the interaction of microbes in the presence of the ingredients being tested. This interaction requires the metabolic activity of strains, which in turn necessitates bacterial propagation. Our initial challenge was first to define normal skin representing species and to identify cultivation conditions that allow the propagation of eight to ten different strains, each with unique requirements.

Since bacterial growth and diversity are key performance indicators for skin microbiome interaction claims, we needed to establish precise monitoring and detection methods for each species. This went beyond Petri dish plating — which cannot distinguish related species within a genus — or measuring optical density. The development of specific quantitative PCR [polymerase chain reaction] methods was a breakthrough in precision, allowing us to eliminate time-consuming sequencing campaigns.

Finally, we successfully established high-throughput methods for cultivation, DNA extraction, and qPCR analyses, which were crucial for running replicates and testing different dosages of the ingredients.