Published Research

World Leaders in Skin Microbiome Biodiversity Research

"Our cutting edge Skin Microbiome Biodiversity Research is done in association with top universities in Europe."

"The aim of our research is to try and find out the cause of the Skin Allergy Epidemic in the Western World."

Sam and Kit
The Skin Twins

Table of Contents

Paper #1: Our discovery of the first skin health measuring mechanism using biodiversity

Meta Analysis of the Skin Microbiome

Meta Analysis of the Skin Microbiome: New Link between Skin Microbiota Diversity and Skin Health with Proposal to Use This as a Future Mechanism to Determine Whether Cosmetic Products Damage the Skin.


There is a skin allergy epidemic sweeping across the western world. Many things in our modern environment are thought to contribute. But how do we find out which ones? 

We realised that, despite many attempts to link certain types of bacteria on the skin to health or disease, there was no clear way of measuring skin health. 

Our groundbreaking discovery was that the diversity of the microbes on the skin was the only reliable indicator of how healthy it is.  This is the same throughout nature, where high biodiversity is seen in healthy ecosystems.

‘Caveman’ skin, untouched by modern civilisation, was very different to “western” skin and had the highest levels of bacterial diversity ever seen. The less exposed communities were to western practices, the higher the skin diversity – clear evidence of an environmental factor in the developed world damaging skin.

In the paper we give benchmark values of diversity against which we can measure skin to determine how healthy it is. This gives us the ability to be able to predict which people are more likely to be prone to skin ailments, and start to test whether synthetic cosmetic ingredients and products are a main cause of the skin allergy epidemic.

Paper #2: Are synthetic ingredients in every day cosmetics damaging the skin?

The Role of Every-Day Cosmetics in Altering the Skin Microbiome

The Role of Every-Day Cosmetics in Altering the Skin Microbiome: A Study Using Biodiversity.


The results from our second paper indicated that the more synthetic ingredients a cosmetics product contains, the more they maintain the damaged western skin microbiome.

Using the skin health measuring mechanism created in Paper 1 and in collaboration with The Medical University of Graz, thirty-two human participants tested three different face washes for their effect on the skin’s microbial diversity, washing twice-a-day for four weeks. The upper volar forearm of the volunteers was swabbed at the beginning, two weeks in and at the end of the four weeks.

One leading ‘natural’ brand with 70% synthetic ingredients, a leading synthetic brand with 75% synthetic ingredients and a 100% natural face wash were used.

The results indicated that the more synthetic ingredients a cosmetics product contains, the more they maintain the damaged western skin microbiome. This paper was the first indications of a link between synthetic ingredients in a cosmetics product and its effect on skin microbiome biodiversity. Future larger studies could lead to the restriction in cosmetics of products proven to harm the skin’s natural environment. 

Paper #3: Is transepidermal water loss a good measure of skin health?

Transepidermal Water Loss and Microbial Biodiversity on the Skin?

Is There a Relationship between Transepidermal Water Loss and Microbial Biodiversity on the Skin?


The results indicated that there was not a link between TEWL (transepidermal water loss) and microbial diversity on the skin. 

As described in previous work, TEWL (transepidermal water loss) is used as an indicator of skin barrier function and health by scientists at top research institutions. However, it is known to be unreliable because many other factors determine its value, such as humidity, temperature and moisture content of the skin.

In this study we used correlation analysis and the Pearson correlation coefficient to compare values of skin microbial biodiversity with TEWL. In our previous 2017 work, microbial biodiversity was found to currently be the only reliable indicator of skin health. All data was taken from that obtained in Paper 2.

Results showed no linear correlation between microbial biodiversity and TEWL rates or any of the other variables. This suggests the need for researchers to make conclusions about TEWL rates and their meaning with regards to skin health with caution. 

Paper #4: What does "Healthy" Western Skin look like?

A New Benchmark to Determine What Healthy Western Skin Looks Like

A New Benchmark to Determine What Healthy Western Skin Looks Like in Terms of Biodiversity Using Standardised Methodology


Our 2020 paper finds a benchmark for measuring healthy western skin using biodiversity of the skin microbiome. Our preliminary results also showed adults aged 28–37 have the highest average diversity, and adults aged 48–57 have the lowest average diversity.

The primary objective of this study was to obtain a benchmark value for the microbial diversity found on healthy western skin, using the Chao1 index. This benchmark was used to update our 2017 skin health measuring mechanism. It used 50 human participants from Graz in Austria and at a read depth of 6600 sequences, we found the average Chao1 diversity to be ~180. 

Previous work with a larger sample size was unsatisfactory to use as a benchmark because different diversity indices and evaluation methodologies were used. Because of this study, we can transfer other benchmarks of skin microbiome diversity to the methodology used in this work from our 2017 study, such as “unhealthy western skin” and “caveman/perfect skin”. This could help with assessing whether patients need help strengthening their skin. 

In future work, we aim to improve our mechanism by obtaining benchmark diversity values from a larger sample size for any age, sex, body site, and area of residence, to which subjects can be compared. 

Paper #5: The Microbiome and Topical Steroid Withdrawal

Strengthening the Microbiome for People with Steroid Withdrawal

Could Strengthening the Gut and Skin Microbiome Help after Stopping Long Term Topical Steroid Use?

Allergies, (Volume 2 Issue 1), Published: 24 December 2021, 10.3390/allergies2010001

Co-authored with:

– Dr. Anja Gijsberts-Veens (Practice for Functional Medicine) –

The Microbiome Center (The Netherlands)

Our 2021 paper showed that skin and gut microbiome interventions could help skin condition of patients suffering with adverse effects after stopping long-term topical steroid use.

The average improvement in skin symptoms for all participants was 40%, and average symptom improvement ranged from 14% for Patient 5 to 92% for Patient 1. On average, the participants saw an improvement in 85% of their symptoms and stagnation or regression in 11% and 4%, respectively.

After commonly being prescribed for eczema, cessation of topical steroid use, especially after long periods of inappropriate use, can leave lasting adverse effects on the body and skin, known by some as topical steroid withdrawal (TSW).  

The skin microbiome was addressed by using a 100% natural product shown to significantly increase skin microbiome biodiversity. Three of seven participants implemented dietary changes and supplementation in response to fecal sample analysis.

The small sample size and lack of a control group means that more definitive conclusions should be reserved for our follow-up work.

Paper #6: Effectiveness of topical Probiotics

Topical Probiotics Do Not Satisfy New Criteria for Effective Use

Topical Probiotics Do Not Satisfy New Criteria for Effective Use Due to Insufficient Skin Microbiome Knowledge.


Our 2021 paper proposed a set of criteria for topical probiotics to adhere to for safe and effective use for the skin microbiome. To form the basis of the criteria, we redefined the term “probiotics” and discussed successful and unsuccessful high-profile examples of the artificial addition of organisms to ecosystems in nature to understand what worked and what did not. Probiotics are often immediately assumed to have health benefits. However, as ecologists are aware, interfering with ecosystems is potentially catastrophic. The addition or removal of just one organism can significantly upset the delicate ecosystem balance. If our criteria are not met, we argue that topical probiotics could also cause damage and will not be beneficial. Due to the large intra- and inter-personal variation of the skin microbiome, our current knowledge of a healthy skin microbiome composition is not complete enough to fully satisfy the criteria. In follow-up work, we will investigate whether current topical probiotics research and commercial products meet our new criteria. We will also discuss problems with how to measure their effectiveness and suggest alternative solutions to replacing the lost biodiversity of the skin microbiome that was stripped away by environmental factors in the Western world.

Paper #7: Commercial Topical Probiotics

The Majority of Commercial Topical Probiotics Do Not Contain Live Microbes and May Not Be Safe or Effective

Commercial Topical Probiotics for the Skin Microbiome: The Majority Do Not Contain Live Microbes and May Not Satisfy Criteria for Safe and Effective Use

Currently under submission, Pre-Print available here.

In this paper we aim to help topical probiotics research and development achieve its potential as an incredible future solution for skin problems by investigating whether the current products on the market satisfy criteria for safe and effective use on the skin microbiome. As previously defined, this includes whether they use microbes known to be part of a healthy skin microbiome and in healthy amounts. In addition, we evaluate whether they contain live microbes, and therefore can be classified as probiotics according to the WHO’s definition. Using recent market analysis at least 84% of products do not contain live microbes. Of the products that appeared to use live microbes, they contained those used in research and development of probiotics for the gut. Due to the varying composition of each person’s microbiome, there is not a one size fits all probiotic solution. Personalisation of probiotics products is essential to satisfy the criteria for safe and effective use, but none of the products on the market, understandably, offer this. Upsetting the delicate ecosystem balance of the skin microbiome could have damaging effects and regulation could help to stop a loss of trust between consumers and cosmetics industry. Future work will perform an in-depth evaluation of the topical probiotics on the market in the EU, USA, and Canada. We will also investigate how to move the topic closer to achieving its potential by updating the criteria, including by discussing how to measure the success of a probiotic solution.

Paper #8: Sports Recovery and Performance

Could The Skin Microbiome Affect Sports Recovery And Performance?

Short Communication: Could The Skin Microbiome Affect Sports Recovery And Performance?

Currently under submission, Pre-Print available here.

This short communication reports on the initial results of a much larger, ongoing project, the aim of which is to investigate the question: could the skin microbiome, just like the gut microbiome, play a role in sports recovery and performance – and if so, could this role be as significant a one as that played by the gut microbiome? 17 high performance college athletes addressed their skin microbiome by minimizing contact with synthetic chemicals and by using topical skin supplements, shown previously to significantly increase skin microbiome biodiversity, for two weeks after training. 76% said their skin softness improved, 35% said their muscle stiffness and recovery after sport improved, 12% said their sleep quality improved, and 100% said they would be likely to use skin supplements again. Future work will use hundreds of athletes.

Paper #9: Damaged Skin causing Chronic Disease?

Is Damaged Skin a Major Contributor to the Chronic Disease Epidemic?

TITLE: A Catastrophic Biodiversity Loss Is Being Replicated on the Skin Microbiome: Is This a Major Contributor to the Chronic Disease Epidemic?

Read the full paper here!

Everyone knows about the “catastrophic biodiversity loss” happening in the world’s ecosystems, due to human intervention. It is also becoming more widely known in the gut, where a significant loss of microbial diversity in the gut microbiome is associated with “most of the human diseases affecting westernized countries”.

But not many know that the same is happening on the skin. Nor do they understand that damaged skin is now thought to be actively involved in the development of a huge amount of “whole body” diseases, not just those affecting the skin.

What is the Microbiome?

This is vital for understanding our papers!

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