606 JOURNAL OF COSMETIC SCIENCE
with the antimicrobial-free yeast-derived active at 0.01%, 0.1%, and 1.0% in vitro prevented
the growth of detrimental microorganisms assessed within 30 seconds and maintained a
commensal microbiota environment.
As displayed in Table III and Figure 3 above, the signaling molecules from the untreated
dendritic cells are unable to kill 100% of all the microorganisms assessed at any of the time
intervals. Additionally, the untreated dendritic cells at the thirty-minute time interval
killed 85.1%, 84.3%, and 62.3% of S. aureus, P. aeruginosa, and S. epidermidis, respectively.
These results indicate that the signaling molecules from untreated dendritic cells allowed
for growth of both the detrimental and commensal microorganisms evaluated.
Conversely, the signaling molecules from the treated dendritic cells with any of the
concentrations prevents all growth of the detrimental microorganisms, S. aureus and P.
aeruginosa, at every time point. Additionally, the media from dendritic cells treated with
0.01%, 0.1%, and 1.0% of the antimicrobial-free yeast-derived active left the S. epidermidis
alive at the 30-minute time interval by 56.1%, 55.5%, and 56.5%, respectively. By allowing
the commensal microbiota to remain on the skin, it is beneficially repairing the skin’s
microbiome and normalizing the epidermal barrier.
At this moment, there is not a full understanding of how the antimicrobial-free yeast-
derived active is interacting with the commensal bacteria and selectively destroying the
pathogenic bacteria. However, the working hypothesis is the ingredient activates dendritic
cells to release certain signaling molecules that target pathogenic bacteria. There are
currently more experiments being conducted to identify and characterize the types and
amounts of signaling molecules released from dendritic cells.
However, the basis and outcomes of the dermal microbiome-immunology assay are highly
significant, marking a revolutionary step forward in the emerging field of immunocosmetics.
By unraveling the complex crosstalk within the skin microbiome and immunity, it provides
a crucial tool for understanding how to effectively modulate and enhance skin health.
This innovation enables researchers and skincare developers to unlock the mysteries of the
skin microbiome, leading to targeted treatments and personalized cosmetics that leverage
microbiome manipulation for optimal skin wellness.
Figure 3. Time kill results for dendritic cells treated with an antimicrobial-free yeast-derived active
inoculated with the tested microorganism populations across time intervals. Values indicate the percent of
microorganisms killed.

607 SKIN MICROBIOME INNOVATIONS
A notable limitation of this model is that, while it effectively evaluates the impact of various
cosmetic ingredients on individual and combined bacterial species commonly found on the
skin, the experiments are conducted under controlled laboratory conditions. It is critical to
acknowledge that certain skin bacteria, such as C. acnes, are capable of forming biofilms,
which can significantly alter their behavior in comparison to planktonic structures.
CONSUMER CLARITY
This new study brings new opportunities on how to bridge the gap between the scientific
community and the everyday beauty consumer. The scientific community is witnessing
firsthand the ability to manipulate the vast environment that lives on the skin in a way
that does not disturb the beneficial microbes and simultaneously helps repair and maintain
the epidermal barrier. Scientists are discovering ways to signal the body to heal itself. It is
crucial to standardize and clearly communicate this process so that consumers understand
the importance of products that support the skin’s microbiome.
By examining the gut health industry, it is clear that they effectively address a problem:
take probiotics and the bloating will stop. They have invested time and effort into
educating consumers about what a “probiotic” is and how it will benefit them. In contrast,
the personal care industry falls short in both education and solutions regarding the skin’s
microbiome. What problem are they solving? Beyond the average consumer, the phrase
“microbiome friendly” is not necessarily well-defined scientifically.
To provide clarity to consumers, the personal care industry must take several crucial steps.
With scientific breakthroughs already available and more on the horizon, it is imperative
that industry does not let this knowledge go to waste. The first valuable step is educating
the consumer. Most consumers currently do not associate their skin issues with the skin
microbiome, nor are they familiar with the specific microbes involved. Furthermore,
addressing the common misunderstanding that all bacteria are bad bacteria is important
as well. However, the consumer interest in learning is present as seen by the growing
appreciation of immunocosmetics. In 2022, the market size for global microbiome skin
care products was valued at $381.5 million and is expected to grow at a compound annual
growth rate of 10.9% from 2023 to 2030.16 This solidifies the potential for microbiome
success in the personal care industry.
The second step is highlighting the problem. Anti-aging has been the forever goal of beauty
consumers. However, skin and scalp conditions such as acne, eczema, atopic dermatitis,
psoriasis, rosacea, dandruff, and dry scalp hinder that goal from being reached and affect
a sizable portion of the global population. Even minor issues like skin inflammation can
be linked to the skin microbiome. Due to the popularity of these common conditions, it
makes sense that the expected global microbiome skin care market is expected to grow so
much in the next ten years.16
This ties in the third and ultimate step: present consumers with a solution. Educate them
that when the skin’s microbiome is disrupted or there is an overgrowth of certain bacteria
strains, these unwanted conditions can arise. Commercially available services, known
as “microbiome profiling,” offer detailed analysis of the skin’s microbial communities.
Examples of companies providing such services include HelloBiome and Skin Trust
Club.17,18 Additionally, simple explanations, engaging visuals, and attention-grabbing
signs on products can make a significant difference in helping consumers understand