Report ICADA Seminar: Expert Seminar Microbiome-Cosmetics

On September 13, 2018, the BAV Institute and the European Cosmetic Association ICADA (organizer, Dr. Brunke) organized the first expert seminar on microbiome cosmetics in Germany, MyMicrobiome (Dr. Neumann, www.mymicrobiome.info) moderated and reported on the seminar.

MyMicrobiome led through the following topics:

• Microbiological examination methods for cosmetics
• Mechanisms of action and achievable effects of cosmetic agents
• Product concepts for the skin microbiome
• Market potential
• Proof of efficacy of microbiome cosmetics
• Regulatory situation in Europe

The topic microbiome has already broadly manifested in the cosmetics industry

The human microbiome is an "ecological community of commensal, symbiotic and pathogenic organisms that share our body space" (Lederberg et al., 2001) or, as already defined in 1988: "[…] the microbiome may be defined as a characteristic microbial community occupying a reasonably well defined habitat which has distinct physio-chemical properties. The term thus not only refers to the microorganisms involved but also encompasses their theatre of activity." (Whipps et al., 1988).

For the layman, a largely unknown term, the topic microbiome has already broadly manifested in the cosmetics industry. It is clear that a well-balanced, healthy skin microbiome directly correlates with skin health. The expert seminar "Microbiome-Cosmetics" shed light on the current state of the art of skin microbiome and discussed the possibilities for the cosmetics industry to positively influence the skin microbiome and thus the skin's health.

Characterization and investigation methods of microorganisms

At the beginning, practical topics such as characterization and investigation methods of microorganisms were explained. Some methods to classify bacteria used today are based on methods that are over 100 years old (microscopic examinations, classification of bacteria with Gram staining into gram-positive and gram-negative bacteria). Above all, however, the microbiological methods for investigating the presence of bacteria in a particular habitat are not nowhere near to form a picture of the microbiological situation. Only about 1% of the microbes actually present can be found using conventional methods such as cultivating microorganisms, since the remaining 99% do not grow in the laboratory.

Today, thanks to the rapid development of molecular biology methods, we can now find the remaining 99% of the microorganisms. However, when we look at the skin, we encounter another hurdle: the type of sampling.

The type of sampling of the skin microbiome plays a major role

Looking at the microbiome of the skin, the stem microbiome is not on the skin surface, but in the deeper layers of the epidermis (resident microbiome). On the skin surface are mainly microorganisms, which we have just snapped, from the last doorknob, the last hand shaking, etc. (transient microbiome). With a simple contact sample or swab we only take a sample of the transient skin microbiome, which in the morning can be different than in the evening. If you want to know exactly, a biopsy of the skin would have to be made. A good middle course is the tear-off method, in which a Tesa strip "tears off" the same skin area up to 10 times. This also gives you a look into the deeper skin layers. However, this type of sampling has the disadvantage that it is limited to a very small area of ​​skin.

The infinite variety of the skin microbiome does not simplify the analysis

The variability of the analysis methods of the skin microbiome is accompanied by a far greater complexity: the infinite variety of the skin microbiome. Compared with different landscapes of the earth, the skin can be divided into different ecosystems, which are unique in the colonization with microorganisms. The highest microbial diversity can be found in the dry skin areas such as the forearms or the back of the hand. The greasy areas such as the forehead, back or nostrils are predominantly colonized by cutibacteria (formerly known as propionibacteria). The highest bacterial density is found in the humid areas such as the armpit or the knee and arm bends. But not only the diversity on different skin areas of a human being is very high, in addition comes the variability of the colonization between humans!

Is it even possible to develop a microbiome-friendly cosmetic product?

This raises the question: how is it possible to develop a cosmetic product that takes into account, on the one hand, the diversity of the different skin areas of a human and, on the other hand, the great variance among humans? Prof. Lang from the TU Berlin proposed to focus on supporting the core microbiome of the skin. Healthy skin is 90% populated with the bacterium Staphylococcus epidermidis, followed by Cutibacterium and Corynebacterium. The high diversity of the skin microbiota represents only a small proportion of the total germ count on our skin.

Although the subject of skin microbiology is very complex and we still understand very little about it, a large number of cosmetic products that address skin microbiology are already available on the market. These promote "improvement of the microbiome", "activation of bacteria", "conservation of the microbiome", etc. Terms such as probiotics, prebiotics and postbiotics, known from the food industry, are used.

Are probiotics and prebiotics useful for the skin?

While pro- and prebiotics are clearly defined in the food industry, there is no definition in the cosmetics industry. The FAO / WHO defined probiotics in foods as "living microorganisms that, when administered in sufficient quantities, confer health benefits to the host." Despite this definition, inactivated non-living bacteria are often referred to in cosmetics as "probiotic." In addition, the currently used "probiotics" for the skin are the same bacteria as the probiotics used for the gut, usually Lactobacillus or Bifidobacterium. However, the composition of the skin flora is fundamentally different from that of the intestinal flora! Probiotics for the intestinal flora cannot survive on the skin, apart from the questionable benefit for the skins microbiome.

The same applies to prebiotics for the skin. These also come from the field of intestinal prebiotics, mostly fructose (FOS). However, the skin microbiome does not have the enzymatic tools to digest it. Here, too, science has to catch up with the market.

But after all the bad news comes good ones: some companies have been able to identify and scientifically validate (microbial) components that either have a positive effect on the skin microbiome or on the skin's health. Some of them were presented at the seminar (see also Interview with Dr. Cath O'Neill). All technologies rely on lysates (shredded cells) of a specific microbial strain. On the one hand, such lysates have shown efficacy on skin health (by increasing skin barrier, improved skin renewal and reduction of unwanted germs), on the other hand the lysate of a specific Lactobacillus strain has promoted the growth of commensal skin flora over the pathogen S. aureus.

Further topics of the seminar dealt with the missing requirements for efficacy studies of microbiome cosmetics and not yet established regulations in the cosmetics regulation.

New standards have to be set in the cosmetic industry

Cosmetics are tested for their quality, for example at the BAV, but none of the quality tests is specific to the influence on the microbiome. Since the microbiome is indispensable in the cosmetics of tomorrow and the current cosmetics also influence our microbiome, new standards have to be set regarding the quality of cosmetic products. Some pioneering test methods were presented by Dr. Bruenke (Managing Director MTC, bruenke-mtc.de):

• Exclusion of negative influences on skin microbial bacteria
• Maintaining the protective functions of the skin through the body's own skin microbiome
• Treatment of microbially caused diseases
  
  

Ultimately, however, the effects of microbiome cosmetics must also be investigated in humans.

Currently, microbiome cosmetics are not yet regulated. According to Article 2 (1) (a) of the Regulation of the European Parliament, ‘cosmetic product’ means any substance or mixture intended to be placed in contact with the external parts of the human body (epidermis, hair system, nails, lips and external genital organs) or with the teeth and the mucous membranes of the oral cavity with a view exclusively or mainly to cleaning them, perfuming them, changing their appearance, protecting them, keeping them in good condition or correcting body odours;

Cosmetic associations such as ICADA or Cosmetics Europe are currently discussing in the working group for borderline products of the European Commission how to classify microbiome cosmetics products in this definition. The word skin microbiome does not appear concretely in this definition, but it can be considered as part of the skin. Keeping the skin in good condition can also involve the microbiome, as a healthy microbiome ensures healthy skin. The previously used term "skin flora" could now be replaced by the term “skin microbiome”. Now the question is, should the wording in the cosmetics industry be based on the definition, should the definition be broader or should it be redrafted in case of a groundbreaking innovation such as the inclusion of the microbiome into cosmetics?

There is disagreement as to whether an influence on the microbiome, i.e. bacteria, does not even fall into the biocide regulation. It is clear that a reasonable solution must be found.

The microbiome has already found its way into the cosmetics industry

The bottom line of this seminar is that awareness of the microbiome and its impact on our health has already entered the cosmetics industry. Although the research on skin microbiology is still very young and more questions are open than answered, some cosmetic products for the microbiome are already on the market. Some are taking advantage of the trend and using phrases such as "pro- and prebiotics for the skin" without any scientific basis, others are intensively searching for the right molecules or bacterial strains that have been proven to promote our skin microbiome and skin health. The cosmetic consumer, just as in the food industry, must be mindful of which product is really useful. If the scientific background for the product is missing, you can save yourself the money. The question that reputable cosmetics manufacturers should ask themselves is how can I, with the current state of science, develop really meaningful products for a healthy microbiome? First of all, it is certainly necessary to disturb the microbial inhabitants of our skin as little as possible. If one limits oneself to the consideration of the "core microbiome" of the skin, one can certainly also find approaches to positively influence the microbiome.

A quality control standard for microbiome cosmetics products should be set as soon as possible to give the consumer a measuring tool. Furthermore, the EU Commission must find a solution for the meaningful classification and regulation of this new type of cosmetics.

All in all, it is a very positive development that our little symbionts, who are more useful than harmful to us, finally find the attention they deserve.