Effect of the skincare product on facial skin microbial structure and biophysical parameters: A pilot study

Skin-associated commensal microorganisms and their metabolites

The skin microbiome is an essential component on our skin and is critical for the maintenance of skin health. It consists of a diverse ecosystem of bacteria, fungi, and viruses. Different body sites in humans exhibit vastly different levels of sebum, temperature, and pH, therefore the microbes that colonize these areas have adapted to create a niche for colonization. Healthy microbial diversity is important in the normal function of the skin, and imbalances in microbial diversity in the skin microbiome have been found to correlate with several skin diseases, such as atopic dermatitis, acne vulgaris, psoriasis, and chronic wound infections. These microorganisms, especially commensal bacteria, produce various metabolites such as short-chain fatty acids, antimicrobial peptides, siderophores, and tryptophan-derived metabolites. These metabolites can interact with and aid the host in processes, such as wound healing and colonization resistance. Metabolites produced by skin commensals have promising therapeutical potential for drug-resistant bacterial infections in place of conventional antibiotics to combat widespread antibiotic resistance. In this review, we will discuss the composition of the skin microbiota and the different classes of metabolites produced by its members, as well as how changes in the skin microbiome impact certain disease conditions.

International expert consensus recommendations for the use of dermocosmetics in acne

BACKGROUND

A wide variety of dermocosmetics (products with both active skincare and cosmetic activity) are available for the management of acne vulgaris. These products are important because they may be the first line of approach for patients desiring to self-treat and they can also have beneficial effects-reducing lesion counts and improving global acne severity. When used in conjunction with medical therapy, dermocosmetics can improve tolerability and enhance results. We reviewed available evidence and combined it with our clinical experience to help guide clinicians in selecting skincare products with acne-targeting ingredients.

METHODS

An international panel of dermatologists with an interest and expertise in managing acne performed a literature review, formulated clinical questions related to the role of dermocosmetics in the acne setting, used a modified GRADE approach to evaluate available evidence and then utilized an online iterative Delphi process to create consensus recommendations. It should be noted that due to the limited number of available studies, the category of dermocosmetics was evaluated rather than specific ingredients.

RESULTS

The quality of evidence was found to be low to moderate. Key recommendations were made based on available evidence for the use of dermocosmetics in acne to improve acne global assessment, reduce acne lesion counts, reduce superficial skin oiliness and serve as maintenance therapy after medical treatment, while providing a good tolerability. Recommendations were also made for using dermocosmetics as adjuncts to medical treatment.

CONCLUSIONS

While there is a need for better quality evidence, dermocosmetics have demonstrated some benefit for acne both when used alone in its milder clinical presentations or in maintenance post acne medication and as adjunct to acne treatments.

Influence of Cosmetic Skincare Products with pH < 5 on the Skin Microbiome: A Randomized Clinical Evaluation

INTRODUCTION

The human skin acts as a protective barrier against external pathogens and hosts a diverse microbiome consisting of bacteria, fungi, viruses, and archaea. Disruptions to the skin microbiome can impact immune function, leading to inflammatory and autoimmune conditions. The importance of pH for the microbiome is paramount. Cosmetic skincare products interact with the skin microbiome and skin pH, playing a key role in maintaining microbial balance. Research suggests that products with non-physiological pH levels may disrupt the skin microbiota. Our clinical study aimed to evaluate the effects of low-pH cosmetic products (pH < 5) on the skin microbiome, contributing to improved skin health.

METHODS

The clinical study focused on evaluating the skin microbiome diversity following the application for 28 days of four different low-pH cosmetic products (vitamin C, resveratrol, a collagen mask, and a native algae mask) on the forearms of post-menopausal women with skin pH > 5.5.

RESULTS

The diversity of the natural skin microbiome increased consistently throughout the study, evident in both the untreated area and after the application of the Vitamin C Concentrate, Resveratrol Concentrate, Collagen Mask, and Native Algae Mask, as indicated by Shannon's diversity index. The native algae mask notably reduced the Corynebacterium genus and significantly lowered the pH. The skin pH changes corresponded with microbiota stability.

CONCLUSIONS

In conclusion, enhanced diversity of the natural skin microbiome was observed over the study duration. None of the investigational products caused significant disruption to the skin microbiome diversity, as evidenced by the stable Shannon's diversity index and relative abundance of specific genera. Notably, the native algae mask significantly decreased the presence of the opportunistic pathogenic Corynebacterium genus, which is likely attributable to a minor reduction in skin pH following extended product use. The findings suggest that the use of low-pH skincare products, like the native algae mask, do not disrupt skin microbiome diversity and may have the potential to positively impact skin microbiome diversity and health by reducing certain pathogenic microbial populations.

Facial Skincare Routine Adherence in the General Population

Introduction The COVID-19 pandemic sparked an interest in skincare with the closure of spas and salons. Skincare, one of TikTok's most popular dermatology-related hashtags, received hundreds of millions of views. The American Academy of Dermatology (AAD) shared facial cleansing recommendations; however,  how many people follow them is unclear. Studies have shown a good daily facial cleansing and moisturizing routine can increase microbiome diversity and skin hydration. This can be beneficial in conditions like psoriasis, eczema, and acne. Purpose The aim of the study is to assess how well people follow the AAD recommendations and evaluate any differences in this behavior by gender. Methods A 19-question survey was designed and administered utilizing Qualtrics. The questions included demographic information, facial cleansing practices, and motivation for skincare routine. The survey was distributed via Rowan Email and on various social media platforms (GroupMe, Instagram, etc.) to target the general population. The data was analyzed using SPSS. Results One hundred twenty-four responses were collected from 91 female-identifying and 33 male-identifying participants. There were statistically significant differences between genders for the use of non-alcoholic gentle cleanser (p<0.001), use of moisturizer after washing the face (p<0.001), washing the face after sweating (p<0.001), and using warm water (p=0.026). No statistically significant difference was seen for face washing occurrence between genders (p=0.098). Statistically significant differences were seen between genders for motivation: hygiene (p<0.001), beauty/anti-aging (p<0.001), and health (p=0.004).  Conclusion Individuals who identify as female may be more likely to adhere to AAD facial skincare recommendations. This could be a result of self-reported motivations such as hygiene, beauty, and health.

Hidden Links Between Skin Microbiome and Skin Imaging Phenome

Despite the skin microbiome has been linked to skin health and diseases, its role in modulating human skin appearance remains understudied. Using a total of 1244 face imaging phenomes and 246 cheek metagenomes, we first established three skin age indices by machine learning, including skin phenotype age (SPA), skin microbiota age (SMA), and skin integration age (SIA) as surrogates of phenotypic aging, microbial aging, and their combination, respectively. Moreover, we found that besides aging and gender as intrinsic factors, skin microbiome might also play a role in shaping skin imaging phenotypes (SIPs). Skin taxonomic and functional α diversity was positively linked to melanin, pore, pigment, and ultraviolet spot levels, but negatively linked to sebum, lightening, and porphyrin levels. Furthermore, certain species were correlated with specific SIPs, such as sebum and lightening levels negatively correlated with Corynebacterium matruchotii, Staphylococcus capitis, and Streptococcus sanguinis. Notably, we demonstrated skin microbial potential in predicting SIPs, among which the lightening level presented the least error of 1.8%. Lastly, we provided a reservoir of potential mechanisms through which skin microbiome adjusted the SIPs, including the modulation of pore, wrinkle, and sebum levels by cobalamin and heme synthesis pathways, predominantly driven by Cutibacterium acnes. This pioneering study unveils the paradigm for the hidden links between skin microbiome and skin imaging phenome, providing novel insights into how skin microbiome shapes skin appearance and its healthy aging.

Valorisation of tomato pomace in anti-pollution and microbiome-balance face cream

Tomato pomace, the main by-product of tomato processing, is also an underestimated source of many active substances. This study aimed to determine the possibility of using oil obtained from tomato pomace in a face cream formulation. The bacterial community structure, face skin biophysical parameters and protection against air pollution were examined after daily application of the cosmetic by volunteers. In the tomato pomace oil, the profile of fatty acids was determined by GC‒MS, and the profile of volatile compounds was determined using the HS-SPME technique. The dominant bioactive component in the oil was linoleic acid (63.6%), and among the volatile compounds, it was carvotanacetone (25.8%). The application of the cream with tomato pomace oil resulted in an increase in the dominant genera Staphylococcus, Anaerococcus and Cutibacterium in the epibiome, particularly beneficial Staphylococcus epidermidis, while limiting the growth of the potentially opportunistic pathogens Kocuria spp., Micrococcus spp., Veillonella spp., and Rothia spp. This study showed the usefulness of tomato pomace oil as a natural ingredient in skin care cosmetics, reducing skin inflammation, sensitivity and melanin level, with potential protective effects against air pollution and microbiome-balance properties. Tomato pomace, which is commonly considered waste after tomato processing, can be used in the development of new cosmetics and may additionally contribute to reducing environmental nuisance.

Acne microbiome: From phyla to phylotypes

Acne vulgaris is a chronic inflammatory skin disease with a complex pathogenesis. Traditionally, the primary pathophysiologic factors in acne have been thought to be: (1) altered sebum production, (2) inflammation, (3) excess keratinization and (4) colonization with the commensal Cutibacterium acnes. However, the role of C. acnes has been unclear, since virtually all adults have C. acnes on their skin yet not all develop acne. In recent years, understanding of the role of C. acnes has expanded. It is still acknowledged to have an important place in acne pathogenesis, but evidence suggests that an imbalance of individual C. acnes phylotypes and an alteration of the skin microbiome trigger acne. In addition, it is now believed that Staphylococcus epidermidis is also an actor in acne development. Together, C. acnes and S. epidermidis maintain and regulate homeostasis of the skin microbiota. Antibiotics, which have long been a staple of acne therapy, induce cutaneous dysbiosis. This finding, together with the long-standing public health edict to spare antibiotic use when possible, highlights the need for a change in acne management strategies. One fertile direction of study for new approaches involves dermocosmetic products that can support epidermal barrier function and have a positive effect on the skin microbiome.

Skin Deep: The Potential of Microbiome Cosmetics

The interplay between the skin microbiome and its host is a complex facet of dermatological health and has become a critical focus in the development of microbiome cosmetics. The skin microbiome, comprising various microorganisms, is essential from birth, develops over the lifespan, and performs vital roles in protecting our body against pathogens, training the immune system, and facilitating the breakdown of organic matter. Dysbiosis, an imbalance of these microorganisms, has been implicated in a number of skin conditions such as acne, atopic dermatitis, and skin cancer. Recent scientific findings have spurred cosmetic companies to develop products that preserve and enhance the skin's microbial diversity balance. These products may incorporate elements like prebiotics, probiotics, and postbiotics, which are beneficial for the skin microbiome. Beyond topical products, there's increasing interest in ingestible beauty supplements (i.e. oral probiotics), highlighting the connection between the gut and skin. This review examines the influence of the microbiome on skin health and the emerging trends of microbiome skincare products.

Impact of Leave-on Skin Care Products on the Preservation of Skin Microbiome: An Exploration of Ecobiological Approach

Purpose

Skincare products are used daily to maintain a healthy skin, although their skin microbiome impact is still poorly known. Preserving the natural resources and mechanisms of the skin ecosystem is essential, and a novel approach based on these premises, called ecobiology, has recently emerged in skincare. We evaluated the impact on the skin microbiome of three types of leave-on face skincare products: a hydrophilic solution, a micellar solution, and an oil-in-water emulsion.

Patients and Methods

Samples for microbial profiling were obtained from 20 Caucasian females twenty-four hours and four days following daily application of the skincare products and compared to an untreated area. The bacterial diversity and the abundance of the skin microbiome were analyzed by 16S rRNA gene sequencing using an Illumina MiSeq platform.

Results

Our results confirmed the skin microbiome diversity and the prevalence of Cutibacterium spp. and Staphylococcus spp. at sebaceous sites. The bacterial diversity and abundance were not affected by the products, and no dissimilarities versus the control nor between each product were noted at both times.

Conclusion

These preliminary results demonstrate for the first time that three types of leave-on face skincare products have no impact on the human skin microbiome and can be considered to be "microbiome friendly".

Oral and Topical Probiotics and Postbiotics in Skincare and Dermatological Therapy: A Concise Review

The skin microbiota is a pivotal contributor to the maintenance of skin homeostasis by protecting it from harmful pathogens and regulating the immune system. An imbalance in the skin microbiota can lead to pathological conditions such as eczema, psoriasis, and acne. The balance of the skin microbiota components can be disrupted by different elements and dynamics such as changes in pH levels, exposure to environmental toxins, and the use of certain skincare products. Some research suggests that certain probiotic strains and their metabolites (postbiotics) may provide benefits such as improving the skin barrier function, reducing inflammation, and improving the appearance of acne-prone or eczema-prone skin. Consequently, in recent years probiotics and postbiotics have become a popular ingredient in skincare products. Moreover, it was demonstrated that skin health can be influenced by the skin-gut axis, and imbalances in the gut microbiome caused by poor diet, stress, or the use of antibiotics can lead to skin conditions. In this way, products that improve gut microbiota balance have been gaining attention from cosmetic and pharmaceutical companies. The present review will focus on the crosstalk between the SM and the host, and its effects on health and diseases.

Influence of Sex on the Microbiota of the Human Face

The role of the microbiota in health and disease has long been recognized and, so far, the cutaneous microbiota in humans has been widely investigated. The research regarded mainly the microbiota variations between body districts and disease skin states (i.e., atopic dermatitis, psoriasis, acne). In fact, relatively little information is available about the composition of the healthy skin microbiota. The cosmetic industry is especially interested in developing products that maintain and/or improve a healthy skin microbiota. Therefore, in the present work, the authors chose to investigate in detail the structure and composition of the basal bacterial community of the face. Ninety-six cheek samples (48 women and 48 men) were collected in the same season and the same location in central northern Italy. Bacterial DNA was extracted, the 16S rDNA gene was amplified by PCR, the obtained amplicons were subjected to next generation sequencing. The principal members of the community were identified at the genus level, and statistical analyses showed significant variations between the two sexes. This study identified abundant members of the facial skin microbiota that were rarely reported before in the literature and demonstrated the differences between male and female microbiota in terms of both community structure and composition.