9 Microbiome Myths Debunked by Industry Experts

A report published in 2023 in Nature Microbiology (NM)¹ highlighted human microbiome myths and provided explanations for them by experts in academia. With surging interest in this field from our industry – the skin microbiome, in particular – we thought it prudent to gather responses to these myths from cosmetic industry experts, to provide clarity and guidance.

The bacterial DNA found on the skin's surface does not accurately represent the actual viable skin microbiome, indicating a potential discrepancy between genetic material and living microbes in skin microbiota."

Featured here are six myths from the report,¹ selected for their relevance to our industry, plus three of C&T’s own, gathered from industry chatter. Included with each are the original (abridged) NM explanations or C&T’s rationale (for its three “myths”), followed by responses from cosmetic industry experts.

1. Microbiome Research is a New Field

NM comment: While the pace of research in this field has greatly accelerated in the past 15 years, history of research into human-associated microorganisms goes back at least to the late nineteenth century. (E. coli described in 1885; bifidobacterial in 1899; gut microbiome 1900s.)

Briggs: It is true that the first report of the diversity of bacteria living in and on the body was in the early 1680s by Antonie van Leewenhoek, and that the link between bacteria and human health was made in the late 19th century by Louis Pasteur and Robert Koch. However, it wasn’t until the 1950s that the idea that resident bacteria could be beneficial was first suggested, and this could be considered the start of true microbiome studies.

Hillebrand: This is clearly a myth, as Walker and Hoyles discussed in their article. Skin microbiome research also goes back to the 19th century and before. The 1960s were probably the beginning of the modern age of the skin microbiome, built on the clinical work of skin scientists and dermatologists who recognized the role of the skin “microflora” in skin health and disease. Most notable were Richard Marples, Albert Kligman and Howard Maibach. Head and Shoulders was invented back in the 50s and is a microbiome-based technology (ZPT) for the treatment of dandruff.

Tiesman: I think people get the impression that microbiome research is recent because the tools to study them (metagenomics, metratranscriptomics, etc.) have really become more powerful over the past several years and are providing massive amounts of valuable data. The microbiome is very complex and the laboratory and analytical tools are only starting to catch up. However, most microbiologists had an appreciation that the complex microbiome plays an important role in human health for many years.

Durack: Microbiology is an ancient science based on understanding how a single organism affects the human body, which was culture/microscopy-based and largely driven by understanding pathogenic interactions to treat or prevent infections. Although there was an acceptance of commensal microbes or “normal flora,” their presence was largely dismissed as a nuisance in the quest for the one pathogenic isolate.

Microbial ecology of the human microbiome, which is focused on understanding how microbial residents interact with each other and help to establish and maintain the physiology of a human body in health and disease, however, has only been possible through recent adaptation of culture-independent next-generation sequencing (NGS) approaches, adapted from environmental ecologists.

Human microbiome research, especially that of low biomass communities such as the skin, is only in its infancy and we are only beginning to understand its complexity. More studies of the skin microbiome in diverse populations, especially underrepresented communities, are needed to broaden our understanding of the true complexity of the skin microbiome and how it relates to skin health.

Weiss: Although microbiology has a long history as a scientific discipline, the microbiome as a field of study is very young, only recently emerging with the convergence of classical microbiology, microbial ecology, molecular biology, immunology and computational biology. The convergence of reductionist scientific fields into a more complex and dimensional systems biology discipline is the hallmark of a true scientific revolution.

The overwhelming complexity of the microbiome, which was all but invisible to us until very recently, is transforming classical reductionist microbiology into a systems biology discipline in which everything is connected in ways that we couldn’t imagine and are only just beginning to appreciate.

Steyn: Van Leeuwenhoek found “animalcules” in his wife’s mouth in the 1600s but I don’t think that anyone understood the microbiome as a co-evolved ecosystem until genetic sequencing revealed the diversity and complexity of it.

2. The Human Microbiota Outnumbers Human Cells 10:1

NM comment: This myth seems to have originated from a “back of the envelope” calculation in the 1970s. More detailed analyses indicate that the true figure, albeit still impressive, is probably closer to a ratio of 1:1. It should be noted that the ratio is likely to vary from person to person.

Briggs: This argument is constantly doing the rounds, and both 1:1 and 10:1 could be right, depending on definitions. (Editor’s note: for more on this topic, see Lawrence). It all depends on whether the non-nucleated red blood cells are considered as human cells.

A very recent paper in PNAS² up-to-date estimates that the male adult human body contains 36 trillion cells, of which 7 trillion are nucleated and 29 trillion are non-nucleated. It also estimates the average human body contains 38 trillion bacteria. If you include the non-nucleated red blood cells, the ratio is approximately 1:1 (38 trillion: 36 trillion). If you discount the red blood cells, then the ratio is over 5:1 (38 trillion: 7 trillion).

To complicate matters further, it has been estimated there are 10¹⁵ phage in the gut alone,³ so if we consider phage as part of the microbiome, then the ratio is more like 100:1 microbiome cells to human cells. I can then throw in the question of whether mitochondria are ancient bacteria⁴ so are they part of the human cell calculation or the microbiome calculation?

My opinion is [that] the question is essentially meaningless anyway: cells of the human microbiome are so tightly entwined with human metabolism and survival that the human microbiome should be considered part of the human organism, and to be human means you are an amalgam of both eukaryotic and prokaryotic cells.

Hillebrand: Walker and Hoyles point out that this ratio is largely variable depending on the amount of feces in the colon and the number is probably more like 1:1. The number of bacteria, fungi and viruses living on skin is body site dependent with oily sites having higher biomass compared to dry sites. If you Google “bacteria per square centimeter of skin,” you find numbers ranging from 1500 to 32 million!

Tiesman: This one is interesting because it depends on how you define microbiota. The reference NM uses compares human to bacterial cells. However, the microbiota also contains fungi, viruses (including host viruses and bacteriophages), protozoa and archaea. Nobody has successfully cataloged all of these (yet), so I think the jury is still out. Also, the number of human and microbial cells is dynamic, so this ratio (whatever it may ultimately be) shifts not only person to person but over time in the same person.

Durack: The truth is we are never going to get an exact number as all the calculations are estimates; they are certainly variable from person to person and in all honesty, the number doesn’t matter [because], as our understanding of the skin microbiome is expanding, we realize that “who is present” is somewhat irrelevant. The more meaningful insight is provided by uncovering “what are these microbes doing” on the skin, their interaction with one another and the host.

Weiss: It should be noted that the accuracy of this microbial census is the least interesting aspect of this meme. It originated within the scientific community almost 50 years ago and only recently has gained popularity among the general public. This is in part due to the intriguing notion that we are “more microbe than (wo)man.” When it was later revised downward to a 1:1 ratio, some were openly disappointed, having found this new, chimeric human identity appealing. Nonetheless, focusing solely on the number misses the point.

It may also be a bit misleading as these numbers are just estimates suggesting precision where none exists. And while there are many other interesting microbiome memes to explore, this one has made a complex, invisible abstraction tangible to the public in a way that more interesting memes have not.

So, let’s not get hung up on the details. Let’s celebrate that it has successfully taken hold, captured public interest in the microbiome and continues to circulate, starting conversations and making the invisible world of microbes visible.

Steyn: The [NM] paper referred to deals only with bacteria. The microbiota includes fungi, archaea and most importantly, viruses. There are approximately 10 viruses for each bacterium (overwhelmingly phages), so the 10:1 figure could still be quoted. I prefer to quote 1:1 … it’s impressive enough. As a side note, it is closer to 1:2.2 for women.

3. The Microbiota is Inherited from the Mother at Birth

NM comment: Although some microorganisms are directly transferred from mother to baby during birth, proportionally few microbiota species are truly “heritable” and persist through from birth to adulthood in the offspring.

Briggs: There is some evidence that the infant microbiome can be influenced by the mother, with a noticeable difference between vaginal birth and C-section, but these changes do not persist into adulthood. Perhaps more interesting is the fact that your microbiome can be modified by and partially acquired from your family, your pet dog or cat, or even the office you work in.

Hillebrand: I believe the same holds true for the skin microbiome. There was some belief that babies born by vaginal delivery had a much more natural and diverse microbiome than those delivered cesarian. However, that has been largely debunked.

Tiesman: [I] agree. Your individual microbiome is a combination of you and your environment. As a baby, your microbiome looks a lot like your mother’s microbiome because she is usually the first microbiome you come into physical contact with. Over time, this shifts and you begin to develop your own microbiome and this continues to change as you age and as you encounter changes in your external environment.

Durack: The skin, being the outermost lining of the body, is constantly influenced by the environment and associated microbes. Our life experiences shape the composition of our skin microbiome, and this process begins at birth. Delivery mode reflects the skin microbiome postpartum, which is relatively quickly replaced by familial microbes shared between family members and influenced by the indoor microbiome.

Our early life exposures set the stage and influence microbial colonization; hence, siblings have more similar skin microbiomes. Then, our individual exposures further shape our microbiomes; in identical twins, for example, the microbiomes diverge in composition with age over time, reflective of each individual’s lifestyle, but remain closer in composition to each other than unrelated individuals or even their mothers.

Weiss: [no comment]

Steyn: True, as far as I know.

4. Sequencing is Unbiased

NM comment: Sequence-based methods are not perfect. Biases can be introduced at every step of sequence-based studies, from sample collection and storage, through laboratory-based steps such as DNA extraction, to the choice of bioinformatic pipelines and reference databases used to analyze the data. It is important to be aware of the limitations.

Briggs: I don’t believe this to be a “common myth” as I know of no-one who would claim that sequence data is unbiased. Always consider methodology limitations and whether they will unduly influence the question you are trying to answer.

Hillebrand: Regardless of tissue type (skin, feces, saliva, etc.), sequence-based methods do have inherent bias depending on, for example, the sampling method, DNA extraction method, primer used and bioinformatic databases employed. Perhaps the most ignored bias associated with DNA sequencing approaches to microbiome research is that these molecular methods capture the TOTAL population of organisms, both viable and non-viable. And for skin samples, this is especially important.

The bacterial DNA found on the skin's surface does not accurately represent the actual viable skin microbiome, indicating a potential discrepancy between genetic material and living microbes in skin microbiota; see Acosta et al., eLife, 2023.⁵ Most of the viable microbes reside in the follicles and sweat ducts and are responsible for repopulating the skin surface after cleansing.

Tiesman: It used to be a pet peeve of mine when someone (usually a sequencer salesperson) would say that sequencing provides an “unbiased view of the microbiome.” Fortunately, most scientists don’t believe this. Every step, from sample collection to data analysis, introduces some level of bias and variability that must be taken into account starting at the experimental design phase.

Durack: All microbiome studies need to be interpreted in the context of study design since sequence-based methods are highly biased, particularly when it comes to the skin microbiome. The skin microbiome is relatively low in biomass (with, on average, ~10-30% of DNA extracted from a skin sample coming from microbes; the rest is human DNA – so the microbial signal is essentially muted), which makes it technically challenging to work with.

The type of sample collected, the site of collection, how the DNA is extracted, what sequencing methods are used (biomarker sequencing aka 16S rRNA [which variable region, most unfortunately are based on V3-4 when V1 is more relevant to skin] or short-gun metagenomics), the sequencing platform all introduce biases, and this is only upstream of bioinformatics, which itself introduces further biases from QC parameters used, tools by which the contaminates are removed if at all, to the database used for assigning taxonomy or functional attributes.

Does this mean that skin microbiome studies are useless[?] – absolutely not – they just need to be interpreted based on the limitation of each study. But instead of focusing on the differences between studies and getting caught in the minutiae, focusing on similarities in observations across various studies will uncover the real and highly complex signatures of the human skin microbiome.

Weiss: It is important to recognize that all scientific methods come with their own biases and imperfections. While some biases can be easily addressed and standardized, sequencing the microbiome is still very much a work in progress. Even with established standard consortia, every sequencing method still has its share of imperfections and limitations.

The best approach for now is to choose appropriate sequencing method or methods, establish reproducibility (precision), and remain as consistent and transparent as possible consistent to avoid blurring the signal in the noise of sequencing bias. At best, we are still precisely inaccurate. Embrace the uncertainty of this young and complex science. As our methods continue to improve, it is almost certain that the complexity of our problems will also increase.

Steyn: [This is] definitely true. We have gone to some length to reduce bias in our lab but it is impossible to eradicate it. We run controls that have known relative abundance of several species so that we can estimate the bias.

Our understanding of the skin microbiome is primarily based on studies of Caucasians residing in metropolitan US/Europe. Relatively few studies have characterized the skin microbiomes of other ethnicities, and even fewer accounted for differences in their lifestyle."

5. We Need Standardizing Methodologies

NM comment: While this belief is sensibly grounded in a desire to make it easier and more robust to compare results from different studies, as noted, there are no methodologies that are perfect, and all are biased in some way. If everyone in the world is using the same method, then everyone is equally blind to the limitations of that approach. There is also the problem of deciding which protocol everyone should use. Increased transparency when reporting methodology choices would be helpful for comparing results from different studies.

Briggs: More important than standardized methodologies are well-thought-out methodologies, with limitations clearly identified and considered. The methodology used will always be dependent on the question you are trying to answer but as long as the methodology is clearly described, then it allows others to use or disregard the data as necessary. Obviously if you are trying to make a comparison, then the methodologies must be equivalent.

Hillebrand: I personally have mixed opinions on this issue. Methods should be standardized in the sense that any one laboratory should have SOPs in place for how they conduct a research method. In that way, results from one experiment can be compared to the next without confounding variables. However, do we all need to use the exact same method? No. Variation in methodology from lab to lab can lead to new discoveries and innovation.

Tiesman: Don’t confuse the need for standards with the need for standardized methodologies. We absolutely need standards to see how closely our experiments are grounded in truth. One organization doing great work in this space is the International Microbiome and Multiomics Standards Alliance organized by NIST.⁶ In terms of methodology, the field is still evolving and, although preferred approaches will emerge (presumably informed by these standards), others will arise to take their place. It is unlikely the field will ever be comfortable recommending a single standardized method.

Durack: Standardizing methodologies for skin microbiome studies is an unfeasible proposition, simply because all methods are imperfect in different ways.

Weiss: [no comment]

Steyn: Again … I agree with this. We just need to be aware of what “color” lens we’re looking through and we need to be transparent about this.

6. Most of the Human Microbiota is ‘Unculturable’

NM comment: A reasonably large proportion of the bacterial and archaeal component of our microbiota has already been cultured from as early as the 1970s. Although cultivation is undeniably labor intensive, has biases and often requires expensive equipment and media, there are clear advantages to having microorganisms in culture. These include enabling mechanistic experiments, verifying genomic predictions and developing them as novel therapeutics.

Briggs: As our understanding of the human microbiome advances, the question of whether we can grow an individual species or not becomes less important. What we need to achieve is the ability to grow and experiment on mixed cultures, preferably including human host cells as well, as no species lives normally in isolation.

Hillebrand: Totally agree with NM comments. We got away from culture-based methods when the cost of DNA sequencing came down to an affordable price. Good microbiome research should be a combination of culture-based and culture-independent methods.

Tiesman: As a molecular biologist, I have too much respect for microbiologists to use the word “unculturable.” Let’s just say “uncultured (yet).” Culturing is a critical aspect of understanding microbes. Again, fungi and viruses/phages are particularly challenging but not impossible. Culturing gives us additional insights into the microbes that we cannot normally get using other techniques.

Durack: My view of “unculturable” is that microbiologists have not figured out how to isolate that microbe yet; this is where the NGS aided cultivation strategies will come in handy. But likely, this term does not apply to the skin microbiome, since it’s composed of microbes we already know how to grow ex vivo.

Weiss: [no comment]

Steyn: While this is largely true, there are microorganisms that are very difficult to culture. Some rely on partnerships with other microbes. Others rely on very specific niches that may be almost impossible to replicate in the lab. We’re interested in the degree to which species have co-evolved and have come to rely on a mutually beneficial partnership. We’re trying to show this more clearly in our lab with multi-species fermentations.

7. Can You Truly Change the Skin Microbiome?

C&T comment: It’s been said that you may change the skin microbiome, e.g., with prebiotics, probiotics, postbiotics or even harsh cleansers/products, but this is temporary as it will revert to its original state. Can you change it? And if you change the balance, does this become the new “normal,” or will it require topical/supplemental maintenance? Lastly, are these various approaches affecting the microbes or the communication between them?

Briggs: The bacteria living upon the skin will be dependent on the local environment: change the skin and you will change the species that can survive there and will make up the skin microbiome. Even something as simple as a moisturizer will change the skin environment, and so can change the resident microbiota. Keep using the moisturizer and the new microbiome will become the new “normal.”

We know this to be true because the changes in the skin associated with aging leads to a change in the microbiome; it is even possible to predict the age of a person by the bacterial species living on their skin. This proves the human skin microbiome “can” be changed. Conversely, changing the skin microbiome without a corresponding change in the skin environment will be very difficult.

Hillebrand: Most of the research shows that the skin microbiome on healthy skin is stable and resilient to everyday perturbation, including exposure to hygiene products (cleansers and soaps) and cosmetic products; even those containing antimicrobial preservatives. This high “microbial inertia” is, in fact, a hallmark of a healthy microbiome and makes a lot of sense from a “by nature’s design” standpoint.

If the skin microbiome were not stable, but rather fragile and susceptible to change by everyday skin care routines or environmental factors like UV exposure, there would be a much higher incidence of skin problems and disease. Prebiotics, probiotics and postbiotics have a more important role in helping to reestablish a balanced microbiome for those with skin microbiome dysbiosis.

Tiesman: A great deal of research over the years has focused on the “plasticity” of the microbiome (i.e., how the microbiome is shaped by external influences). Historically, most of this work has focused on the gut. Scientists have found that, although the microbiome tends to shift with changes in the environment (for instance, diet, stress, medicine and even travel), when these changes are removed, it tends to revert to a personal “resting state.” Other niches, including the skin, are very likely to behave the same and early work confirms this.

Durack: What we know about the skin microbiome today is that it is dynamic; it changes over time in response to intrinsic and extrinsic factors. The real issue in my mind that the field is currently facing is the elusive “normal skin microbiome” – the directionality of change is missing. What is normal to you at this given moment in your life journey? We will not be able to define that “normal” if we look at the microbiome as a stand-alone entity. We need to better understand how the microbiota interacts with itself and with the host. Which brings it back to: it’s not “who is there on my skin” but what are “these microbes collectively doing” and how is my skin responding to this microbial signaling.

An important point I would like to emphasize is that our understanding of the skin microbiome is primarily based on studies of Caucasians residing in metropolitan US/Europe. Relatively few studies have characterized the skin microbiomes of other ethnicities, and even fewer accounted for differences in their lifestyle. However, what we are discovering by expanding the population demographic is that the skin microbiome of people residing in rural environments is vastly different from that of urban dwellers and less preconditioned by cleansers/products (i.e., more susceptible to intervention). These findings are beginning to challenge what constitutes a “normal” skin microbiome. There is still so much more to be uncovered; this is truly an exciting time for this field.

Weiss: There is ample evidence that we can alter the relative abundance of the skin microbiome with cosmetics as well as pre/pro/post biotics; selective prebiotics and antimicrobial postbiotics, for example. However, interpretation and clinical correlation of these shifts in abundance have yet to be established, with a few notable exceptions (atopic dermatitis, xeroderma).

Even more challenging has been achieving sustained engraftment of a probiotic for more than a few weeks. While probiotic engraftment remains an active area of microbiome research, it appears that colonization resistance prevails and ejects the newcomer. The best results so far have been achieved in young children and strain-level engraftment of established species.

Steyn: The skin microbiome is robust. This is because it is primarily housed in the pilosebaceous unit and, to a lesser extent, in the eccrine glands. The microbes that we swab on the surface are “seeded” from the glands below. This microbiome can certainly be changed. For example, antibiotics have a clear effect. The changes that we induce can disrupt the stable state of the ecosystem in the long term … years even … but generally speaking, the effects are relatively short-lived.

Larry Wiess has shown that there is a more delicate biofilm that should be in place on the surface. This seems likely but it seems that modern humans have lost this.

8. Is There Evidence That Dysbiosis Can Cause Skin Conditions?

C&T comment: Skin microbiome dysbiosis has reported alongside some skin conditions. Do we know if it is partially the cause? Or is this more of an association? Also, how might this work – do microbes act on the immune system, for example?

Briggs: To have a dysbiotic microbiome also requires there to a symbiotic microbiome, and we have yet to define the normal healthy microbiome. The evidence suggests that what would be normal for one person could be out of balance for another: the state of symbiosis and dysbiosis is personal to the person.

That said, when people suffer from acne or eczema, and have cycles of flare and remission, there is normally a corresponding cycle in the skin microbiome, and if the microbiome is in a state of flux, this is likely to have a state of dysbiosis. Whether the dysbiosis causes the flare or affects the intensity of the duration of the flare is the critical point. An argument can be made that if killing or reducing bacteria by treating with antibiotics leads to an improvement in the skin condition, then the bacteria must be, at [the] very least, contributing toward the condition.

Hillebrand: Back in 1971, Kligman and coworkers inoculated skin with S. aureus, which elicited an erythema rash in three days and then papulo-vesicular eruption in six days. Removing the bacteria was followed by a return to healthy skin. While performing this kind of clinical study would never be allowed today, the results should not be ignored as one of the few examples of how microbiome dysbiosis can directly cause clinical skin disease.

We can also take lessons from the gut microbiome. Food poisoning is microbiome dysbiosis causing diarrhea. Fecal microbiome transplants are an example of treating disease (C. diff infection) with a healthy consortium of gut bacteria. FDA approval of Vowst (Seres Therapeutics, Inc.) is inspiration that similar or more advanced technology can be used in RX, cosmetic and personal care to help people with skin problems ranging from dermatitis to wrinkling.⁷

Tiesman: Microbes produce metabolites in order to influence other microbes around them and to influence their host (i.e. us). Therefore, it is highly likely that microbes influence both health and disease states and there are great examples emerging in the scientific literature showing a causative role for microbes. This is especially true for skin conditions like psoriasis, eczema and even dandruff.

Durack: Skin microbiome is important in establishing and modulating immune responses; as such it is not surprising that specific shifts in the microbiota have been associated with a variety of inflammatory skin conditions. Our understanding of the mechanisms by which they arise is limited because they are so multifaceted.

In my opinion, we cannot continue to view the role of the microbiome in skin conditions through an outdated lens of clinical microbiology. Most skin inflammatory conditions (specifically acne, rosacea, psoriasis and atopic dermatitis) challenge the foundational principles of infectious disease – they are not contagious, i.e., sharing a towel with your friend with acne will not make you break out. They arise from the disrupted balance between the individual’s immune (and endocrine, in the case of acne) system and their microbiota compositions. To truly understand the etiology of these conditions, we need to start approaching them as a system’s biology puzzle, which is fundamentally what they are.

Weiss: [no comment}

Steyn: A robust, diverse microbiome is required for healthy skin in the same way that microbes are essential for gut health. The microbiome and skin have co-evolved over the last 1.9 million years, in which our ancestors have been furless. We now need our microbes as much as they need us. Human skin is a strange environment and has resulted in a microbial set that is highly adapted to the niche. Many species can’t survive anywhere else on the planet.

Sebum is the primary nutrient source for the microbes on our skin. In our sebum, we produce fatty acids like sapienic acid that are not found in any other animal. Our coevolved microbes can use these eclectic fatty acids as nutrients but these acids are toxic to invading microbes.

If we have the wrong mix of microbes in skin, there will certainly be poor outcomes. To fully restore skin health, we need to apply selection pressures to our skin’s ecosystem that favor our coevolved partners. Many modern skin care norms don’t take this into consideration.

We cannot continue to view the role of the microbiome in skin conditions through an outdated lens of clinical microbiology. ... To truly understand the etiology of these conditions, we need to start approaching them as a system’s biology puzzle.

9. Is the Skin Microbiome a Promising Area for the Future of Personal Care?

C&T comment: Some experts think the microbiome is just marketing hype. Is it? Why or why not?

Briggs: Understanding the skin microbiome is no more or less of a promising area for the future of cosmetics than is understanding of the dermis or the epidermis. The skin microbiome is an integral part of the skin, and to understand the skin we must understand the skin microbiome. We do not yet understand the role of the skin microbiome in holistic skin biology or behavior but we are starting to understand what the correct questions are.

Hillebrand: YES! However, much of it is marketing hype and many of the products on the market that claim to be microbiome-based technology do so [with] little to [no] evidence. Simply saying “microbiome friendly” or “balances the microbiome” are easy claims to make in the cosmetic industry. Delighting the consumer with microbiome technology that delivers consumer-noticeable benefits is much more difficult.

To date, I would say there are few, if any examples of clinically proven technology on the market. That is not to say we won’t get there. As mentioned above, we can take a lot of inspiration from our gut microbiome friends. An FDA-approved microbiome-based drug for the treatment of atopic dermatitis may be the first to come to market.

Tiesman: The microbiome is not the only component of skin health, but it does play a key role. As such, it is a very promising area of research. While we shouldn’t overhype the microbiome’s role, we can’t ignore it either. It is yet another component of a complex biological system that needs to be taken into account in order to understand (and promote) healthy skin.

Durack: I absolutely think that the skin microbiome is an essential factor in the development of beneficial and efficacious personal care products; the field is still in its infancy but is primed for breakthroughs. Unfortunately, for now, products targeting skin microbiome remain a “marketing hype” – one could argue that perhaps we need that hype to accelerate innovation in this field.

Weiss: Both [views] are correct. Today, most of the marketing claims concerning the microbiome are, at best, based on a thin economy of scientific evidence. There are many reasons for this, but the fact is that ours is a very young science and while our knowledge is finite our ignorance is infinite.

To our marketing colleagues, the microbiome is the latest “new thing,” and marketing is driven by economic, not scientific incentives. As professionals, we are all privileged to participate in this emerging science and should strive to be responsible stewards. There is little doubt that in the future, microbiome science will transform and improve every aspect of human health, including skin, diet, health care, the environment and more. We are not there yet and there is work to be done. Let’s aspire to respect this emerging science and maintain our credibility until that day arrives.

Steyn: The recent discovery of the extent of the skin microbiome fundamentally changes our view of skin. Skin should now be viewed as a co-dependent ecosystem that is beautifully intricate and almost intractably complex. Our blunt “better living through chemistry” approach hasn’t worked very well for the macro-ecosystems that we can see around us. It is unlikely to serve us well in the microbial ecosystems that we need for optimum skin health.

This isn’t a trend … it’s a fundamental shift in how we understand skin.

References

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3. Łusiak-Szelachowska, M., Weber-Dąbrowska, B., Żaczek, M., Borysowski, J. and Górski, A. (2020). The presence of bacteriophages in the human body: Good, bad or neutral? Available at https://www.mdpi.com/2076-2607/8/12/2012

4. Nature India. (2022, Jan 27). How mitochondria evolved from bacteria. Available at https://www.nature.com/articles/d44151-022-00006-8

5. Acosta, E.M., Little, K.A., ... Gitai, Z., et al. (2023, Jun 30). Bacterial DNA on the skin surface overrepresents the viable skin microbiome. Microbiology and Infectious Disease. Available at https://elifesciences.org/articles/87192

6. IMMSA. (Accessed 2023, Nov 15). International Microbiome and Multi'omics Standards Alliance (IMMSA). About IMMSA. Available at https://www.microbialstandards.org/