Skin Microbiome – The benefits of understanding your product's effects

Posted On: Jul 16, 2020

Written by

Margaret Butler, Ph.D

Principal Scientist

Here at BioScience Laboratories we see countless studies on a huge variety of focus areas, however more and more there is an increased interest for research on the skin microbiome and its relationship to the immense variety of products we use today. The human microbiome is defined as the collection of all microorganisms living in association with the human body. In recent years, our understanding of the complex microbial interactions and how they affect our bodies has increased substantially. While originally most of the focus was on the microbiome within our digestive system, there is now additional focus on the organisms outside of our bodies as well, mainly on our largest organ, the skin. As a result, questions of how increased use of antiseptics, cosmetics, and other topical products affect this microbiome has become a point of interest for companies operating within these industries. Understanding the recent developments that have brought microbiome research to this point can shed light on the value of understanding a product’s effect on the skin’s microorganisms.

Human Microbiome Project (HMP)¹

In 2012, over 200 members of the HMP Consortium from over 80 universities and scientific institutions published the results of 5 years of research, providing the first comprehensive characterization of the normal microbial composition of the human body. Samples from 15-18 body locations were collected from two hundred forty two healthy human volunteers. The microbial makeup of each site (such as gut, mouth and skin) was characterized by sequencing the DNA of thousands of microbial strains. Major findings of the project showed that the microbiome is composed of multi-species microbial communities and that there were notable differences in diversity and abundance of microbes at the specialized locations, both within an individual and between individual subjects.

Establishment of the Skin Microbiome²

The skin is the largest organ of the human body and functions as a protective barrier to the internal organs of the human body, regulates body temperature, water balance, contains specialized sensory nerve structures, and synthesizes hormones and vitamins. Oil and sweat glands, hair follicles, wrinkles, and folds are some of the structural components that contribute to the functional diversity of the skin. With so much diversity, it is not surprising that over 300 microbial species have been identified in the skin. The skin microbiome is acquired during birth as a baby passes through the birth canal or from the mother’s skin via a Caesarean delivery. Over time, a few primary microbes adapt to living in the different locations of the skin and can colonize. This colonization may slightly change the host’s environment, which in turn allows other microbes to also colonize and eventually an established community is formed which is compatible and beneficial to the host. These established complex communities, sometimes referred to as normal flora, commensal organisms, healthy organisms, or good microbes become a defensive shield against harmful microbes, by the competition for space and nutrients and also by producing substances that inhibit growth of some harmful microorganisms.

Balancing Act of the Skin Microbiome^2,3

In the 8 years following the publication of the HMP foundational database, a vast amount of microbiome research has provided additional important insights. Microbes inhabit almost every part of the human body, totaling trillions of cells, including bacteria, fungi, viruses and protozoans. The composition of an individual’s skin microbiome is dependent on numerous variables such as early microbial exposure, gender, host genetics, diet, environment and lifestyle. All these factors result in the microbiome generally being unique to each human individual. Most of the time, microbes colonize and coexist with humans and can provide beneficial functions essential to the human body such as producing vitamins and anti-inflammatory substances. However, healthy humans can also be colonized by pathogenic microorganisms, yet exhibit no disease. This has led to studies analyzing and comparing the composition of individuals’ microbiomes for correlations with a specific disease state. Familiar examples include the bacteria associated with acne, Cutibacterium acnes, which is present in the skin of all individuals, but becomes problematic in only some cases and Malassezia fungi which is present in the scalp, yet causes dandruff in only some humans. Furthermore, microbial imbalances have been a widely accepted cause of a variety of internal conditions manifesting in otherwise healthy individuals. Candidiasis can be a side effect of antibiotic consumption and a result of reduced levels of healthy bacteria that prevent Candida albicans overgrowth in the body. Understanding the various states of our skin microbiome may open doors for increased safety and efficacy of topical products in several existing industries. The underlying theme which has emerged is that the microbiome is constantly adapting to balance the diversity and abundance of helpful and harmful microorganisms throughout an individual’s lifetime to maintain the complexity of healthy microbial communities.

Within our own Laboratory we have contributed to expand the understanding of the dermal microbiome, specifically on the effect of hygiene products on the hand microbiome⁴.

The Role of Skin Microbiome in Health Care and Cosmetic Products

With the increasing understanding that the skin microbiome plays a major role in maintaining human health, interest worldwide from small and large companies in both the medical and cosmetic fields is rapidly growing. Understanding the colonization process of the skin and the existence of unique complex microbial communities in healthy and diseased individuals has led to the development of microbiome-related products (for personal care and health care) that aid in maintaining or rebalancing the skin microbiome and potentially treating skin conditions. A big challenge of this goal is that different individuals may have different requirements for their unique microbiome. Most microbiome-related products currently described fall into one of three categories; prebiotic, probiotic, or postbiotic

• Prebiotic skin care products are substances that promote the growth of beneficial microorganisms and inhibit harmful microorganisms from thriving on the skin surface. Many of these products contain plant-derived sugars or plant oils that provide a nutritional source for the skin microbiome.
• Probiotic skin care products contain live beneficial microorganisms and are perhaps the most challenging, controversial, and exciting group of microbiome-driven products. Generally, most skin care products contain preservatives, but they cannot be used in probiotics since they will destroy the beneficial microbes. Refrigeration is an option, but not one that consumers prefer. Ultrasound–inactivated bacterial extracts have been used in probiotics. Lactobacillus and Bifidobacterium are commonly used bacteria. Some formulations combine prebiotic and probiotic ingredients so that the nutrients required for bacterial growth are provided as well as the actual bacteria. Genetically engineered bacteria are also being explored to treat skin conditions.
• Postbiotic skin care products contain non-viable bacteria or metabolic by-products, such as enzymes, peptides, sugars, and organic acids, some of which are generated during the fermentation process of probiotic bacteria

Innovative Microbiome-driven Products

A recent article summarized some highlights at how biotech companies are moving towards using the microbiome to treat skin conditions with either commensal bacteria or specifically engineered bacteria.⁵ Listed here are a few of the many creative products being developed:

• A healthy bacterium interfering with the growth of a pathogenic bacterium associated with eczema,
• The isolation of a bacterium found on amphibian skin with anti-fungal properties is being evaluated in a trial to treat Athlete’s foot,
• The production of a new strain of a healthy bacterium whose growth can be controlled such that it can outcompete the colonization of a pathogenic bacterium,
• The engineering of a bacterium which secretes an anti-inflammatory molecule, often found at reduced levels in individuals with acne and psoriasis.

Your Dedicated Skin Technology Experts

There is room for expansion within skin microbiome research, and subsequently many unfulfilled opportunities. Our dedicated skin technology laboratory focuses on providing industry leading research and data collection to give you the tools you need to confidently develop and market your products in this ever-changing industry. We can help you evaluate your skin care product and its effect on the microbiome, implementing a wide collection of methods through custom protocols developed to suit your product’s specific needs. Other offerings include:

• Culture-based analysis and non-culture-based analysis
• In Vitro Laboratory testing and sample gathering
• Clinical Studies including:
  • Subjective questionnaires
  • Visual observations and photography
  • Quantitatively measure skin condition endpoints before/after treatment
  • Moisturization
  • Acne Reduction

References

¹https://commonfund.nih.gov/hmp/overview

²https://thesecretlifeofskin.com/2019/02/11/is-the-microbiome-selfie-set-to-revolutionize-human-health/

³https://www.health.harvard.edu/a_to_z/candidiasis-a-to-z

⁴https://pubmed.ncbi.nlm.nih.gov/28351915/

⁵https://www.nature.com/articles/s41587-020-0473-8#citeas