Though product fads come and go in the skin care world, it appears that microbiome skin care is here to stay. According to recent market studies, one of the fastest-growing segments within the industry is microbiome skin care. ^1,2 Products containing various prebiotics, probiotics, and postbiotics fall within this category, with the purpose to nourish the skin’s microbiome and modulate it back into balance. Restoring balance to the microbiome may potentially resolve numerous skin ailments including acne, rosacea, eczema, psoriasis, and many others. Though traditional treatments and medications, such as steroids or antibiotics, frequently provide successful relief of these skin conditions, the results are often temporary and may come with unwanted side effects. These treatments can negatively impact the microbiome, causing a host of other challenges. Alternately, microbiome products encourage the skin to heal itself by returning the microbiome to homeostasis or balance.

THE MICROBIOME

So, what is the microbiome, exactly? It is a delicate balance of trillions of microorganisms living and functioning together. This balance includes gram-negative and gram-positive bacteria, fungi, viruses, mites, and protozoa. Humans have more microbes living in and on them than their own cells, and it is estimated that the microbiome can weigh up to five pounds. ³ Internally, the microbiome primarily resides in the digestive tract, while externally. While it surrounds and inhabits the skin. It is extraordinarily diverse, and it varies from person to person throughout different locations of the skin on the body.

 As an analogy, the skin’s microbiome could be compared to the earth’s climate and living organisms. Just like the earth, there are areas of dry, desert-like climates with little to no moisture content or sebum production. These areas would include skin on the elbows and front of the knees. There are also humid, rainforest-like regions with copious production of sebum and sweat, such as the skin behind the ears and on the face and décolleté. Like different earth regions, specific microorganisms only reside in certain climates of the skin. ^4,5 When in balance, various organisms protect the skin, defending against potentially harmful pathogens and environmental damage, functioning as a part of the skin’s barrier that maintains overall hydration levels. The microbiome varies throughout one’s life cycle; it is ever-evolving and changes based on the environments it encounters, including hygienic habits, the aging process, and other factors.⁶

      Many experts believe the microbiome is not just a separate entity living on the skin but is instead a functioning organ of the body.⁷ Like an individual’s organs, the microbiome has pathology and physiology, and when altered, it impacts overall health and wellness, potentially resulting in disease. The skin’s microbiome is dependent on food for nourishment, which is provided by dead skin cells and the sweat and oils secreted. Anything that hinders skin’s natural excretions could have a negative impact, such factors include the use of harsh foaming cleansers and over-exfoliation, as well as the natural aging process, which decreases the excretion of sweat and sebum. Other external influences that could damage the skin’s microbiome include antibiotics, sanitizers or disinfectants, preservatives, pollution, and excessive ultraviolet exposure. These are important considerations to highlight regarding skin’s overall care and health, especially now that most clients are exposed to these factors more than ever. New discoveries show that many popular aesthetic treatments on the market can disrupt the microbiome. These treatments include laser resurfacing, microneedling, microdermabrasion, and many other modalities. Many of these treatments destroy skin cells, harshly remove other components of the skin’s barrier, and induce inflammation. It is critical to consider the client’s post-care routine after these treatments, ensuring it is microbiome-friendly and helps to re-establish the skin’s barrier function.

Another crucial factor that determines the microbiome’s strength and robustness is its diversity. Diversity in species living throughout the microbiome, both internally and externally, has been shown to contribute to a more resilient immune system.⁸ For example, those living in rural areas who are exposed to the outdoors, dirt, nature, and animals have been shown to have a more diverse, healthier microbiome. However, not all exposure is positive. People who reside in urban areas with increased pollution are shown to have a less robust immune system and overall lower microbiome health.⁹

ROLE IN SKIN HEALTH

The significance of the microbiome’s role in the skin’s overall health cannot be overstated. Studies show the microbiome can affect almost every aspect of the skin, including hydration levels, inflammation response, immune system regulation, and the ability to build new, strong skin cells.^10,11 Dysbiosis, or an imbalance in the microbiome, is implicated in various skin diseases. It is not merely the existence of these microbes on the skin that cause disease, but rather their overgrowth and invasion into areas of the skin in which they do not belong. Though these imbalances are not necessarily the sole cause of skin diseases, their role in disease formation is well established. Various skin conditions and microbial imbalances associated with them include the following list:

Acne

1. acnes bacteria and formerly known as p. acnes bacteria was traditionally viewed as the primary culprit in causing acne. However, it has been shown that c. acnes also live on healthy skin without an occurrence of acne.¹² It is now understood that only specific strains of c. acnes bacteria are involved in the creation of acne. How these strains interact with other microorganisms living on the skin, as well as the immune system’s response, also play a role in acne formation, not just the organism’s presence on the skin.
2. epidermidis — the most prevalent bacteria living on the skin. Recent studies point to the disharmony of c. acnes bacteria with s. epidermidis as a cause of acne.¹³ Whether through injury to the skin or changes in oil production with puberty, c. acnes can thrive and overgrow, potentially leading to acne formation.

Malassezia is a species of yeast or fungi, implicated in causing acne. Though Malassezia lives harmoniously on healthy skin, its imbalance and invasion into the follicle can cause folliculitis, which appears to the naked eye as traditional acne.¹⁴

Rosacea

Demodex mites reside in the skin, specifically within the sebaceous glands and hair follicles. Their population is relatively harmless for most people; however, those with rosacea have a nearly six-fold increase in these mites’ population density.¹⁵ The mites release a compound called chitin, which can activate an inflammatory cascade seen as redness, telangiectasia, pustules, and thickening of the skin observed in rosacea. Presumably, if there is a six-fold increase in the density of mites populated in rosacea skin. There is also a substantial increase in chitin release, thus impacting the severity of the aforementioned symptoms.

Demodex mites are also the host of a bacterium known as b. oleronius. While this bacterium is relatively harmless on its own, the mites overpopulating the follicle can cause it to become distended or expanded, creating a leak. When the mites die, they release toxins from the b. oleronius bacteria that potentially penetrate through the leak into the follicle. This encounter can lead to a chain reaction of inflammation, creating pustules, redness, and other symptoms related to rosacea.¹⁶

Dermatitis, Eczema, & Psoriasis

1. aureus is more commonly known as staph. This bacterium has proven prevalence in cases of atopic dermatitis and eczema.¹⁷ Though its presence has not been directly correlated as the cause of dermatitis and eczema lesions, it is implicated in the condition’s severity and flare-ups. Interestingly, healthy skin with a balanced microbiome does not allow colonization of s. aureus. However, skin that exhibits dermatitis shows reduced production of antimicrobial peptides that will enable s. aureus colonization, suggesting an imbalanced microbiome.¹⁸

Candida is a yeast-like fungus, and its species have shown some correlation with psoriasis and a flare-up of symptoms.¹⁹ Though candida usually is present on the skin with a healthy microbiome, overgrowth may be due to altered immune function.

PREBIOTICS, PROBIOTICS, & POSTBIOTICS

Microbiome skin care can be incorporated in every step of a client’s routines, including cleansers, toners, serums, and moisturizers. Other emerging applications include probiotic patches that show promise in treating a multitude of skin conditions. As mentioned previously, “microbiome-friendly” products often contain various biotics, such as prebiotics, probiotics, and postbiotics. With all this biotic talk, it can seem overwhelming and confusing. Let us define these components and their role in the skin’s microbiome health.

Prebiotics play a substantial role in the microbiome’s overall health, as they provide food for beneficial microorganisms, or probiotics, that reside internally in the digestive tract and topically on the skin, allowing them to thrive. Though their studied prominence primarily lies in their role in gut health, the skin care industry is beginning to understand the value of prebiotics in treating various skin conditions. By nourishing specific probiotics with targeted prebiotics, skin care professionals can effectively increase probiotic colonies and fend off microbes that cause harmful skin conditions. Sources of prebiotics in skin care include various plant sugars, such as xylitol and galactomannans, and inulin, a plant fiber derived from chicory root. There are also food sources, such as barley, flaxseed, or wheat bran, used as effective prebiotics in skin care to nourish the beneficial probiotics.

Probiotics are live microorganisms with beneficial properties when digested internally or applied topically to the skin. Probiotics are arguably the most well-known and studied object of discussion when referencing the microbiome. Even so, new information is unveiled daily about various probiotic strains and their topical benefits. Historically found in cultured and fermented foods such as yogurt, probiotics are now commonly utilized in supplements and beauty products. Probiotic use in skin care has been shown to improve many skin conditions, including acne, rosacea, and sun damage, as well as slowing the skin’s aging process.

The most recent discovery in biotics is postbiotics, which are the waste materials of probiotics. These include essential fatty acids, amino acids, and other leftover components after a probiotic’s life cycle. Initially viewed as non-beneficial waste, postbiotics potentially play a critical role in flora’s overall health. These spare components lend themselves towards creating an ideal environment on the skin, including establishing an ideal pH for the skin’s barrier function, which allows good microbes to thrive.

To use another analogy for explaining these various biotics, if skin care professionals envision the skin as the soil in a garden, then prebiotics would be fertilizer and probiotics would be the plants that grow in the soil. Postbiotics would be the nutrients leftover after the plants die, eventually recycling back into the soil, providing nutrients to make it an ideal environment for future plant growth. Using harsh surfactants, antibiotics, sanitizers, and anything else that could disrupt the microbiome is the equivalent of a natural disaster ravaging the garden. Imagine these negative factors as a hurricane, flood, or tornado ripping up an entire established ecosystem and creating a blank slate. This opens a window of opportunity for harmful pathogens to establish dominance, causing an infection or skin disease due to an absence of beneficial microbes that keep these pathogens in check. Another important consideration is that each component of the skin’s “garden” is dependent on the other, so it is essential to nourish them all.

CHOOSING BIOTICS FOR THE SKIN

The magnitude of what is still unknown about biotics and their power to restore the skin’s health makes it challenging to determine what is best or most important to incorporate into skin care routines. Additionally, skin care professionals must be mindful to review an entire skin care routine as needed to ensure ancillary products used do not wipe out the client’s skin nutrients and the microbiome itself.

An essential factor to consider when choosing biotics to incorporate into a skin care routine is utilizing specific strains that have verified efficacy in impacting the skin condition – distinct strains and their proven efficacy matter. Research that will make this possible for the masses is still in development, so patience is necessary for both spa professionals and clients. At present, two promising probiotics to explore in skin care are lactobacillus bacteria species and ammonia-oxidizing bacteria (AOB), as both have shown to be effective in addressing a plethora of skin concerns.^20,21

In summary, the microbiome plays a substantial role in the skin’s overall health. This role includes the microbiome itself, how it communicates with the immune system, and how the body responds, as they are all tied together. Skin care professionals are just beginning to understand the microbiome’s various interactions and functions. This creates endless possibilities, exciting prospects, and the potential to treat challenging skin conditions without using chemicals and medications with harmful side effects.

References

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Brian Goodwin is an award-winning international educator for Éminence Organic Skin Care. As a master medical aesthetician, master herbalist, and consultant, Goodwin leverages over 10 years of spa industry experience to bring fun, engaging education to spa professionals around the world. Voted ‘Favorite Brand Educator’ in DERMASCOPE’s 2019 Aestheticians' Choice Awards, he delivers influential trainings which continue to raise the bar for professional education and garner worldwide peer recognition. Goodwin embraces every opportunity to share his passion and guide industry professionals on their path to success. He has educated and consulted to more than 2,000 distinguished spas and has notably been invited to deliver keynotes at major industry events across North America.