Staphylococcus epidermidis and Cutibacterium acnes: Two Major Sentinels of Skin Microbiota and the Influence of Cosmetics

The Effects of Antiperspirant Aluminum Chlorohydrate on the Development of Antibiotic Resistance in Staphylococcus epidermidis

This study investigates the effects of the antiperspirant aluminum chlorohydrate on the development of antibiotic resistance in commensal Staphylococcus epidermidis isolates. The isolates were exposed to aluminum chlorohydrate for 30 days. The bacteria that developed resistance to oxacillin and ciprofloxacin were isolated, and the expression levels of some antibiotic resistance genes were determined using quantitative reverse transcriptase PCR. Before and after exposure, the minimum inhibitory concentration (MIC) values of the bacteria were determined using the microdilution method. A time-dependent increase was observed in the number of bacteria that developed resistance and increased MIC values. Consistent with the ciprofloxacin resistance observed after exposure, an increase in norA, norB/C, gyrA, gyrB, parC, and parE gene expression was observed. In addition to aluminum chlorohydrate exposure, oxacillin resistance was observed in all test bacteria in the group only subcultured in the medium, suggesting that phenotypic resistance cannot be correlated with chemical exposure in light of these data. The increase in mecA gene expression in selected test bacteria that acquired resistance to oxacillin after exposure compared with control groups suggests that the observed resistance may have been related to aluminum chlorohydrate exposure. To our knowledge, this is the first time in the literature that the effects of aluminum chlorohydrate as an antiperspirant on the development of antibiotic resistance in Staphylococcus epidermidis have been reported.

C-Type Natriuretic Peptide Acts as a Microorganism-Activated Regulator of the Skin Commensals Staphylococcus epidermidis and Cutibacterium acnes in Dual-Species Biofilms

The effect of C-type natriuretic peptide in a concentration closer to the normal level in human blood plasma was studied on the mono-species and dual-species biofilms of the skin commensal bacteria Cutibacterium acnes HL043PA2 and Staphylococcus epidermidis ATCC14990. Despite the marginal effect of the hormone on cutibacteria in mono-species biofilms, the presence of staphylococci in the community resulted in a global shift of the CNP effect, which appeared to increase the competitive properties of C. acnes, its proliferation and the metabolic activity of the community. S. epidermidis was mostly inhibited in the presence of CNP. Both bacteria had a significant impact on the gene expression levels revealed by RNA-seq. CNP did not affect the gene expression levels in mono-species cutibacterial biofilms; however, in the presence of staphylococci, five genes were differentially expressed in the presence of the hormone, including two ribosomal proteins and metal ABC transporter permease. In staphylococci, the Na-translocating system protein MpsB NADH-quinone oxidoreductase subunit L was downregulated in the dual-species biofilms in the presence of CNP, while in mono-species biofilms, two proteins of unknown function were downregulated. Hypothetically, at least one of the CNP mechanisms of action is via the competition for zinc, at least on cutibacteria.

The Cystic Fibrosis Upper and Lower Airway Metagenome

The microbial metagenome in cystic fibrosis (CF) airways was investigated by whole-genome shotgun sequencing of total DNA isolated from nasal lavage samples, oropharyngeal swabs, and induced sputum samples collected from 65 individuals with CF aged 7 to 50 years. Each patient harbored a personalized microbial metagenome unique in microbial load and composition, the exception being monocultures of the most common CF pathogens Staphylococcus aureus and Pseudomonas aeruginosa from patients with advanced lung disease. The sampling of the upper airways by nasal lavage uncovered the fungus Malassezia restricta and the bacterium Staphylococcus epidermidis as prominent species. Healthy and CF donors harbored qualitatively and quantitatively different spectra of commensal bacteria in their sputa, even in the absence of any typical CF pathogen. If P. aeruginosa, S. aureus, or Stenotrophomonas maltophilia belonged to the trio of the most abundant species in the CF sputum metagenome, common inhabitants of the respiratory tract of healthy subjects, i.e., Eubacterium sulci, Fusobacterium periodonticum, and Neisseria subflava, were present only in low numbers or not detectable. Random forest analysis identified the numerical ecological parameters of the bacterial community, such as Shannon and Simpson diversity, as the key parameters that globally distinguish sputum samples from CF and healthy donors. IMPORTANCE Cystic fibrosis (CF) is the most common life-limiting monogenetic disease in European populations and is caused by mutations in the CFTR gene. Chronic airway infections with opportunistic pathogens are the major morbidity that determines prognosis and quality of life in most people with CF. We examined the composition of the microbial communities of the oral cavity and upper and lower airways in CF patients across all age groups. From early on, the spectrum of commensals is different in health and CF. Later on, when the common CF pathogens take up residence in the lungs, we observed differential modes of depletion of the commensal microbiota in the presence of S. aureus, P. aeruginosa, S. maltophilia, or combinations thereof. It remains to be seen whether the implementation of lifelong CFTR (cystic fibrosis transmembrane conductance regulator) modulation will change the temporal evolution of the CF airway metagenome.

Recent advances in understanding inflammatory acne: Deciphering the relationship between Cutibacterium acnes and Th17 inflammatory pathway

Acne vulgaris is a common chronic inflammatory skin disease of the pilosebaceous units. Four factors contribute to acne: hyperseborrhea and dysseborrhea, follicular hyperkeratinisation, skin microbiome dysbiosis and local immuno-inflammation. Recent key studies have highlighted a better understanding of the important role of Cutibacterium acnes (C. acnes) in the development of acne. Three major findings in the last decade include: (1) the ability of C. acnes to self-organize in a biofilm associated with a more virulent activity, (2) the loss of the C. acnes phylotype diversity and (3) the central role of the Th17 pathway in acne inflammation. Indeed, there is a close link between C. acnes and the activation of the Th17 immuno-inflammatory pathway at the initiation of acne development. These mechanisms are directly linked to the loss of C. acnes phylotype diversity during acne, with a predominance of the pro-pathogenic phylotype IA1. This specifically contributes to the induction of the Th17-mediated immuno-inflammatory response involving skin cells, such as keratinocytes, monocytes and sebocytes. These advancements have led to new insights into the underlying mechanisms which can be harnessed to develop novel treatments and diagnostic biomarkers. A major disadvantage of traditional treatment with topical antibiotics is that they induce cutaneous dysbiosis and antimicrobial resistance. Thus, future treatments would no longer aim to 'kill' C. acnes, but to maintain the skin microbiota balance allowing for tissue homeostasis, specifically, the restoration of C. acnes phylotype diversity. Here, we provide an overview of some of the key processes involved in the pathogenesis of acne, with a focus on the prominent role of C. acnes and the Th17-inflammatory pathways involved.

Change in Cutibacterium acnes phylotype abundance and improvement of clinical parameters using a new dermocosmetic product containing Myrtus communis and Celastrol enriched plant cell culture extracts in patients with acne vulgaris

BACKGROUND

Acne is a multifactorial chronic inflammatory disease of the pilosebaceous unit, where Cutibacterium acnes plays a main role. Recent papers demonstrated that specific C. acnes phylotypes were correlated with the severity of inflammatory acne and reported a specific loss of C. acnes phylotype diversity in this context.

OBJECTIVES

The aim of this exploratory study was to evaluate the efficacy of a new dermocosmetic product containing Myrtus communis and Celastrol-enriched plant cell culture extracts on C. acnes phylotype abundance and clinical parameters in subjects with mild to moderate acne vulgaris.

METHODS

Cutibacterium acnes phylotype diversity was evaluated by single-locus sequence typing sequencing on the nonlesional areas of the forehead, that is, areas excluding inflammatory lesions (papules and pustules) on day 1 (D1) and after 56 days (D57) of twice daily application of the dermocosmetic product on the whole face. Clinical efficacy on acne was also assessed by acne lesion counting and Global Evaluation Acne (GEA) score on D1 and D57.

RESULTS

Our study confirmed the link between the presence of some C. acnes phylotypes and acne severity. The dermocosmetic cream was linked to a positive impact on C. acnes phylotypes: a significant decrease in pro-pathogen phylotype IC and increase in nonpathogen phylotype IB were observed in the nonlesional areas of acne on D57 compared to D1. In parallel, the clinical results showed a significant decrease in inflammatory and comedonal acne lesions and a significant improvement in the acne severity according to the GEA score.

CONCLUSIONS

This study showed that the application of a new dermocosmetic product containing M. communis and Celastrol-enriched plant cell culture extracts was linked to a change in the C. acnes phylotype abundance and an improvement in acne severity.

Characterization of a live Cutibacterium acnes subspecies defendens strain XYCM42 and clinical assessment as a topical regimen for general skin health and cosmesis

BACKGROUND

When formulating topical products to treat skin diseases and addressing general skin health and cosmesis, most of the focus has traditionally been placed on how any given ingredient may impact the structure, function, and health of human skin elements. However, recent research is beginning to highlight the importance of the skin microbiome in relation to certain skin conditions and general cosmesis. Cutibacterium acnes is one of the most prolific skin-specific bacterial species. Research has shown that the species is divided into subspecies, some of which are thought to be beneficial to the skin. This paper aims to determine the efficacy of strainXYCM42, a C. acnes subspecies defendens derived strain designed to improve the health and appearance of the skin.

METHODS

In vitro studies were performed on human keratinocyte and fibroblast monolayers, human peripheral blood mononuclear cells (PBMC), and skin explants to elucidate the effects of live XYCM42 cells and their ferment on human skin cells and tissues. Subsequently, clinical studies were performed using XYCM42-based topical regimens designed to deliver and support the engraftment of live XYCM42 cells onto subjects' skin. Two studies were performed, a 3-week pilot study (n = 10) and a 8-week pivotal study (n = 121). In the latter, 32 subjects were enrolled for an in-clinic portion for efficacy evaluation, with clinic visits occurring at Baseline, Week 1, Week 4, and Week 8.

RESULTS

In vitro data suggest that XYCM42 and its ferment filtrate have potential to provide benefits to the skin via antioxidant, anti-inflammatory, and select antimicrobial activities. Clinical observation demonstrated that a XYCM42-containing regimen supports a healthy skin environment, promotes increased skin hydration, decreases erythema, calms the skin, and regulates sebum production.

CONCLUSION

These studies provide further evidence that specific strains of C. acnes, such as XYCM42, have a more beneficial function regarding skin health and appearance than was previously thought. Appropriate use of formulations derived from symbiotic strains within the skin microbiome can support the development of novel, beneficial topicals.

Distinct skin microbiome modulation following different topical acne treatments in mild acne vulgaris patients: A randomized, investigator-blinded exploratory study

The effects of topical non-antibiotic acne treatment on skin microbiota have rarely been demonstrated. In the study, we randomized 45 mild acne vulgaris participants into three treatment groups, including a cream-gel dermocosmetic containing Aqua Posae Filiformis, lipohydroxy acid, salicylic acid, linoleic acid, niacinamide and piroctone olamine (DC), retinoic acid 0.025% cream (VAA) and benzoyl peroxide 2.5% gel (BP). At months 0, 1 and 3, skin specimens were swabbed from the cheek and forehead and sequenced by targeting V3-V4 regions of the 16 S rRNA gene. QIIME2 was used to characterize bacterial communities. Acne severity, sebum level and tolerability were assessed concomitantly in each visit. We found that both VAA and BP could significantly reduce the bacterial diversity at month 1 (p-value = 0.010 and 0.004 respectively), while no significant reduction was observed in DC group. The microbiota compositions also significantly altered for beta diversity in all treatments (all p-value = 0.001). An increased Cutibacterium with decreased Staphylococcus relative abundance was observed at months 1 and 3 in DC group, while an opposite trend was demonstrated in VAA and BP groups. These findings suggest a potential impact of DC, VAA and BP on the diversity and composition profiles of the skin microbiota in mild acne participants.

Biocosmetics: technological advances and future outlook

The paper provides an overview of biocosmetics, which has tremendous potential for growth and is attracting huge business opportunities. It emphasizes the immediate need to replace conventional fossil-based ingredients in cosmetics with natural, safe, and effective ingredients. It assembles recent technologies viable in the production/extraction of the bioactive ingredient, product development, and formulation processes, its rapid and smooth delivery to the target site, and fosters bio-based cosmetic packaging. It further explores industries that can be a trailblazer in supplying raw material for extraction of bio-based ingredients for cosmetics, creating biodegradable packaging, or weaving innovation in fashion clothing. Lastly, the paper discusses what it takes to become the first generation of a circular economy and supports the implementation of strict regulatory guidelines for any cosmetic sold globally.

Randomized comparative double-blind study assessing the difference between topically applied microbiome supporting skincare versus conventional skincare on the facial microbiome in correlation to biophysical skin parameters

BACKGROUND

There are trillions of live bacteria, of around 1000 different species, living in human skin which are considered essential for the balance and barrier function of the skin. The gut microbiome has been a subject of extensive research and evidence shows that the gut flora is affected by preservatives and processed foods. In conventional skincare, preservatives are used, and this raises the question of how it affects the skin flora and its balance.

METHODS

A randomized double-blind study on 14 healthy volunteers ages 23-45 years old were advised to use microbiome-supporting (MS) products on one cheek and benchmark (BM) products on the other cheek daily for 3 weeks. To investigate how the skin was affected, the skin microbiome was analysed using 16 S rRNA sequencing and biophysical parameters were assessed using an Antera 3D camera. Measurements were performed before and after the 3 weeks of using the products.

RESULTS

The use of MS products for 3 weeks significantly increased the total number of reads mapped to unique bacterial species (p < 0.05) and the number of different unique species (p < 0.05). In addition, the use of MS products significantly reduced redness (p < 0.05) and improved skin texture (p < 0.01). The use of BM products showed no significant difference in any of the parameters except improved skin texture (p < 0.05). Additionally, the MS side showed a significantly improved diversity (p < 0.05) compared with the BM side. The four major phyla found were, similarly to previous findings by others, Actinobacteria, Firmicutes, Proteobacteria and Bacteroidetes. Some of the most prevalent species were Cutibacterium acnes, Staphylococcus epidermidis and Pseudonomas aeruginosa.

CONCLUSION

The findings of this study showed significant improvements in the microbiome and biophysical parameters within 3 weeks of using MS skincare alone, while BM skincare only gave significantly improved skin roughness. Importantly, the MS side gave a significantly improved bacterial Shannon diversity (p < 0.05) compared with the BM side. Regarding the biophysical parameters, the MS skincare gave significant improvements in several parameters compared with baseline. However, they were not yet significant when compared to using BM skincare and therefore a larger study population will be needed. Importantly, this is the first study to investigate how preservatives affect the facial microbiome in vivo and has raised a need for further investigation. These results together with further studies can lead to innovations within the cosmetic industry that promote healthier skin.

Microbial profile of T-shirts after a fitness session of Chinese students

Clothing textiles could protect our human skin against external factors, but the microbial population, including conditional pathogens, in clothing, would cause unpleasant odor, Skin inflammation, and textile deterioration. Several studies have reported that microbiomes on clothes are affected by skin microorganisms of individuals, the local environment and the types of textile fabrics, but little is known about how the textile microbial community is shaped in the Chinese population. In this study, 10 healthy young students were recruited to successfully wear the T-shirts made with 3 different fabrics (polyester, cotton, and blending fabrics of polyester and cotton) during physical exercise. Total deoxyribonucleic acid (DNA) was extracted from 30 T-shirts and 16s rRNA gene amplicon sequencing was applied to estimate the absolute abundances of bacteria in the samples. The main bacteria on wore T-shirts were Staphylococcus (21.66%) Enhydrobacter (13.81%), Pantoea (8.14%), Acinetobacter (7.81%), Pseudomonas (6.18%), Cutibacterium (4.99%). However, no difference of α and β diversity was observed among the three textile fabrics. Further analysis found that Pantoea and Pseudomonas, mainly from the environment, enriched on the polyester, but not on cotton, while Enhydrobacter, from human skin, has the growth advantage on cotton, and the blending fabric in between. Collectively, our study preliminary explored the clothes microbiome in Chinese young students, contributing to helping understand the role of clothing microorganisms on human health.

Comparative analysis of scalp and gut microbiome in androgenetic alopecia: A Korean cross-sectional study

Androgenetic alopecia (AGA) is a non-scarring and progressive form of hair loss occurring in both men and women. Although genetic predisposition and sex steroid hormones are the main causes, many factors remain unknown, and various extrinsic factors can negatively affect the lifespan of hair. We investigated skin-gut axis microorganisms as potential exogenous factors causing AGA, through comparative analyses of the scalp and gut microbiome in individuals with and without AGA in a Korean cohort. Using 16S rRNA gene sequencing, we characterized the scalp and gut microbiomes of 141 individuals divided into groups by sex and presence of AGA. Alpha diversity indices in the scalp microbiome were generally higher in individuals with AGA than in healthy controls. These indices showed a strong negative correlation with scalp-inhabitant bacteria (Cutibacterium and Staphylococcus), indicating that the appearance of non-inhabitant bacteria increases as hair loss progresses. No significant differences in diversity were observed between the gut microbiomes. However, bacterial functional differences, such as bile acid synthesis and bacterial invasion of epithelial cells, which are related to intestinal homeostasis, were observed. The networks of the scalp and gut microbiome were more complex and denser with higher values of the network topology statistic coefficient values (i.e., transitivity, density, and degree centrality) and more unique associations in individuals with AGA than in healthy controls. Our findings reveal a link between skin-gut microorganisms and AGA, indicating the former's potential involvement in the latter's development. Additionally, these results provide evidence for the development of cosmetics and therapeutics using microorganisms and metabolites involved in AGA.

Antibacterial and Anti-Inflammatory Activities of Thymus vulgaris Essential Oil Nanoemulsion on Acne Vulgaris

Antibiotics are frequently used in acne treatment and their prolonged use has led to an emergence of resistance. This study aimed to investigate the use of natural antimicrobials as an alternative therapy. The antimicrobial and anti-inflammatory activities of five commonly used essential oils (EOs) (tea tree, clove, thyme, mentha and basil EOs), and their possible mechanisms of action against Cutibacterium acnes and Staphylococcus epidermidis, were explored. The effect of the most potent EO on membrane permeability was elucidated and its anti-inflammatory action, when formulated as nanoemulsion, was tested in an in vivo acne model. The in vitro studies showed that thyme EO had the most potent antimicrobial and antibiofilm activity, with phenolics and terpenoids as main antimicrobial constituents of EO. Thyme EO affected cell membrane permeability of both bacterial species, evident by the detection of the leakage of intracellular ions and membrane integrity by the leakage of nucleic acids. Morphological alteration in bacterial cells was confirmed by transmission electron microscopy. Thyme EO nanoemulsion led to the suppression of an inflammatory response in acne animal models along with a bacterial load decrease and positive histopathological changes. Collectively, thyme EO nanoemulsion showed potent antimicrobial and anti-inflammatory effects compared to the reference antibiotics, suggesting its effectiveness as a natural alternative in acne treatment.

Current postbiotics in the cosmetic market-an update and development opportunities

Postbiotics are a new class of health-promoting molecules that derive from probiotics. These new cosmetic and dermatological ingredients are defined as a 'preparation of inanimate microorganisms and/or their components that confers a health benefit on the host'. This review focuses on what is presently known of these compounds, the benefits of using them, the main postbiotics products available in the market and players, the production key trends and available production methods. The main advantages identified for the use of postbiotics are related to their higher specificity of action on resident microbiota as of interaction with cells of the host compared to probiotics. Postbiotics can be produced/obtained especially through fermentative processes, but most of companies industrial processes are patented. Most of these compounds are usually derived from lactic acid bacteria, Lactobacillus genera and/or yeasts, especially Saccharomyces cerevisiae. Postbiotics go from metabolites like teichoic acids to polysaccharides among others and exhibit important biological properties such as antioxidant, anti-inflammatory, anti-proliferative and immunomodulatory-the reason why their use in cosmetic formulations must be considered. Besides that, when compared to probiotics, postbiotics have longer shelf life and greater safety and do not require viability in the topical formulation which turns them into an innovative approach within the cosmetic ingredients market. The main players are companies that operate in several areas, such as the chemical industry, food innovation, pharmaceutical and cosmetic industries, and the critical trends for production of these compounds include energy efficiency, emission-free mobility, conservation of finite resources and renewable raw material utilization. KEY POINTS: • Postbiotics are mainly derived from lactic acid bacteria and S. cerevisiae. • Postbiotics exhibit several biological properties. • Postbiotics present several advantages over probiotics.

Targeting Acne Bacteria and Wound Healing In Vitro Using Plectranthus aliciae, Rosmarinic Acid, and Tetracycline Gold Nanoparticles

Gold nanoparticles from plant extracts and their bioactive compounds to treat various maladies have become an area of interest to many researchers. Acne vulgaris is an inflammatory disease of the pilosebaceous unit caused by the opportunistic bacteria Cutibacterium acnes and Staphylococcus epidermis. These bacteria are not only associated with inflammatory acne but also with prosthetic-implant-associated infections and wounds. Studies have hypothesised that these bacteria have a mutualistic relationship and act as a multispecies system. It is believed that these bacteria form a multispecies biofilm under various conditions and that these biofilms contribute to increased antibiotic resistance compared to single-species biofilms. This study aimed to investigate the antibacterial and wound healing potential of synthesised gold nanoparticles (AuNP_s) from an endemic South African plant, Plectranthus aliciae (AuNP_PAE), its major compound rosmarinic acid (AuNP_RA) and a widely used antibiotic, tetracycline (AuNP_TET). Synthesised gold nanoparticles were successfully formed and characterised using ultraviolet–visible spectroscopy (UV–vis), dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ-potential), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED), and they were investigated for stability under various biological conditions. Stable nanoparticles were formed with ζ-potentials of −18.07 ± 0.95 mV (AuNP_PAE), −21.5 ± 2.66 mV (AuNP_RA), and −39.83 ± 1.6 mV (AuNP_TET). The average diameter of the AuNP_s was 71.26 ± 0.44 nm, 29.88 ± 3.30 nm, and 132.6 ± 99.5 nm for AuNP_PAE, AuNP_RA, and AuNP_TET, respectively. In vitro, biological studies confirmed that although no antibacterial activity or biofilm inhibition was observed for the nanoparticles tested on the multispecies C. acnes and S. epidermis systems, these samples had potential wound closure activity. Gold nanoparticles formed with rosmarinic acid significantly increased wound closure by 21.4% at 25% v/v (≈29.2 µg/mL) compared to the negative cell control and the rosmarinic acid compound at the highest concentration tested of 500 µg/mL. This study concluded that green synthesised gold nanoparticles of rosmarinic acid could potentially be used for treating wounds.

Marine Actinobacteria a New Source of Antibacterial Metabolites to Treat Acne Vulgaris Disease—A Systematic Literature Review

Acne vulgaris is a multifactorial disease that remains under-explored; up to date it is known that the bacterium Cutibacterium acnes is involved in the disease occurrence, also associated with a microbial dysbiosis. Antibiotics have become a mainstay treatment generating the emergence of antibiotic-resistant bacteria. In addition, there are some reported side effects of alternative treatments, which indicate the need to investigate a different therapeutic approach. Natural products continue to be an excellent option, especially those extracted from actinobacteria, which represent a prominent source of metabolites with a wide range of biological activities, particularly the marine actinobacteria, which have been less studied than their terrestrial counterparts. Therefore, this systematic review aimed to identify and evaluate the potential anti-infective activity of metabolites isolated from marine actinobacteria strains against bacteria related to the development of acne vulgaris disease. It was found that there is a variety of compounds with anti-infective activity against Staphylococcus aureus and Staphylococcus epidermidis, bacteria closely related to acne vulgaris development; nevertheless, there is no report of a compound with antibacterial activity or quorum-sensing inhibition toward C. acnes, which is a surprising result. Since two of the most widely used antibiotics for the treatment of acne targeting C. acnes were obtained from actinobacteria of the genus Streptomyces, this demonstrates a great opportunity to pursue further studies in this field, considering the potential of marine actinobacteria to produce new anti-infective compounds.

Culturable bacteria in the entire acne lesion and short-chain fatty acid metabolites of Cutibacterium acnes and Staphylococcus epidermidis isolates

Although evidence supports that the acne microbiome harbors a diverse range of microbes that play a vital role in the progression of acne vulgaris, the culturable microbes in the acne microbiome have not yet been largely identified. Here, we grew microbe colonies from entire acne lesions on agar plates and identified abundant Staphylococcus, Acinetobacter, and Pseudomonas species from forty selected single colonies. Staphylococcus species, including Staphylococcus epidermidis (S. epidermidis), Staphylococcus hominis (S. hominis), and Staphylococcus aureus (S. aureus), were isolated from tryptic soy broth (TSB) agar plates. However, Cutibacterium acnes (C. acnes) was predominately isolated from furazolidone-supplemented TSB agar plates. Results from gas chromatography-mass spectrometry (GC-MS) analysis revealed that, besides acetate, propionate and butyrate were the main short-chain fatty acids (SCFAs) in fermentation metabolites of C. acnes and S. epidermidis isolates, respectively. The culturable bacteria and SCFA profiles presented in this study provide a reservoir for selecting acne probiotics and developing SCFA-associated therapies against acne vulgaris.

Regular Late Bedtime Significantly Affects the Skin Physiological Characteristics and Skin Bacterial Microbiome

Background

Late bedtime is a common form of unhealthy sleep pattern in adulthood, which influences circadian rhythm, and negatively affects health. However, little is known about the effect of regular late bedtime on skin characteristics, particularly on skin microbiome.

Objective

To investigate the changes and effects of the regular late bedtime on skin physiological parameters and facial bacterial microbiome of 219 cases of Chinese women aged 18-38 years living in Shanghai.

Methods

Based on the Self-Evaluation Questionnaire, bedtime was categorized as 11:00 PM; thus, the volunteers were divided into early bedtime group (S0) and late bedtime group (S1). The physiological parameters of facial skin were measured by non-invasive instrumental methods, and the skin microbiome was analyzed by 16S rRNA high-throughput sequencing.

Results

The skin physiological parameters of the late bedtime group exhibited significant decrease in skin hydration content, skin firmness (F4) and elasticity (R2), while TEWL, sebum and wrinkle significantly increased. The result indicated that late bedtime significantly impaired the integrity of skin barrier, damaged skin structure, and disrupted water-oil balance. Furthermore, the analysis of α-diversity, Sobs, Ace and Chao index were found to significantly decrease (P < 0.05) in the late bedtime group, suggesting that late bedtime reduced both the abundance and the diversity of facial bacterial microbiota. Moreover, the abundance of Pseudomonas increased significantly, while Streptococcus, Stenotrophomonas, Acinetobacter, Haemophilus, Actinomyces and Neisseria decreased significantly. In addition, Spearman correlation analysis revealed strong correlations between the microbiota and the physiological parameters. Notably, the abundance of Pseudomonas significantly positively correlated with skin firmness and elasticity, but significantly negatively correlated with skin hemoglobin content, melanin content and skin hydration.

Conclusion

Bedtime is an important factor in maintaining skin health. Regular late bedtime not only damages the skin barrier and skin structure but also reduces the diversity and composition of facial bacterial microbiome.

Examining Skin Recovery After a 3% Aqueous Hydrogen Peroxide (H2O2) Treatment Using ATP Biofluorescence

Introduction

Since its complete mapping, the human skin microbiome has become an important area of research related to skin health. The human skin is populated by an environment of microorganisms, fungi, insects, and viruses that is collectively known as the microbiota, and the complete genomic contribution to the skin is called the microbiome. The terms are different but frequently used interchangeably. Measuring the skin’s microbial diversity can be done, but it is a sophisticated technique that is performed using expensive instruments that can sequence the 16S ribosomal RNA of the microorganisms. Finding more rapid and less costly methods to analyze the changes in the skin’s microbial biome is desirable.

Methods

A study was conducted on thirty (30) inner volar forearms to see if ATP biofluorescence could be employed to examine skin microbial dysbiosis caused by the application of 3% hydrogen peroxide. Fifteen individuals were examined on both arms for a total of thirty inner volar forearms using a Charm Science^® NovaLum^® ATP analyzer to examine in a broad sense the skin’s total microbial population and how it is affected after surface treatment with 3% hydrogen peroxide over a 24-hour period.

Results

It was found that surface treatment of the skin with three cotton swab applications of 3% hydrogen peroxide five minutes apart was able to statistically significantly suppress the expression of ATP biofluorescence compared against un-swabbed sites and the effects remained significant for six hours following the H₂O₂ treatment. After 8 hours, and into the 24th hour, the ATP biofluorescence difference returns to non-statistical significance indicating potential return of the stable microbiota.

Discussion

Using ATP biofluorescence to detect possible sanitizer-induced microbial dysbiosis may be a rapid way to examine how skin treatments may impact the return of microbially disrupted skin to its normal state and how surface treatments may impact the rate of return to normal after a disruptive event.

Analysis on the difference of skin surface lipids during blue light therapy for acne by lipidomics

Acne is a chronic inflammatory skin disease of the sebaceous glands of the hair follicles, caused by a variety of factors and tends to recur, causing skin damage and psychological stress to patients. Blue light (415nm) is a popular physical therapy for acne, however, studies on the effects of blue light on skin surface lipids (SSL) have not been exhaustively reported. So, we want to investigate the difference in SSL before and after acne treatment with blue light and to reveal the potential mechanism of acne treatment with blue light from the lipid level. SSL samples were collected and physiological indicators (moisture content, transepidermal water loss (TEWL), sebum content and pH) were measured. By using ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) with multivariate data analysis methods to obtain specific information on the lipid composition. Analysis of the physiological index data showed a significant increase in moisture content (p = 0.042), pH (p = 0.000) and a significant decrease in sebum content(p = 0.008) in the after treatment area (AT group), while there was no significant change in TEWL values. A total of 2398 lipids were detected by lipidomics analysis and 25 differential lipids were screened. Triradylglycerols (TGs), isoprenoids and hopanoids being the potential differential lipids. Among the lipids associated with the skin barrier, only monounsaturated fatty acids (MUFA) (p = 0.045) were significantly increased. This study revealed significant changes in SSL after blue light treatment for acne, suggesting that blue light exposure may cause changes in the relative lipid content and redistribution of lipid components, and that whether it damages the skin barrier requires further study.

Economic significance of biofilms: a multidisciplinary and cross-sectoral challenge

The increasing awareness of the significance of microbial biofilms across different sectors is continuously revealing new areas of opportunity in the development of innovative technologies in translational research, which can address their detrimental effects, as well as exploit their benefits. Due to the extent of sectors affected by microbial biofilms, capturing their real financial impact has been difficult. This perspective highlights this impact globally, based on figures identified in a recent in-depth market analysis commissioned by the UK’s National Biofilms Innovation Centre (NBIC). The outputs from this analysis and the workshops organised by NBIC on its research strategic themes have revealed the breath of opportunities for translational research in microbial biofilms. However, there are still many outstanding scientific and technological challenges which must be addressed in order to catalyse these opportunities. This perspective discusses some of these challenges.

The Prospects of Swietenia macrophylla King in Skin Care

The importance of cosmetics in our lives is immeasurable. Covering items from daily personal hygienic products to skincare, it has become essential to consumers that the items that they use are safe and effective. Since natural products are from natural sources, and therefore considered “natural” and “green” in the public’s eyes, the rise in demand for such products is not surprising. Even so, factoring in the need to remain on trend and innovative, cosmetic companies are on a constant search for new ingredients and inventive new formulations. Based on numerous literature, the seed of Swietenia macrophylla has been shown to possess several potential “cosmetic-worthy” bioproperties, such as skin whitening, photoprotective, antioxidant, antimicrobial, etc. These properties are vital in the cosmetic business, as they ultimately contribute to the “ageless” beauty that many consumers yearn for. Therefore, with further refinement and research, these active phytocompounds may be a great contribution to the cosmetic field in the near future.

Activity of Silver Nanoparticles against Staphylococcus spp

Staphylococcus epidermidis is a bacterium that is part of the human microbiota. It is most abundant on the skin, in the respiratory system and in the human digestive tract. Also, Staphylococcus aureus contributes to human infections and has a high mortality rate. Both of these bacterial species produce biofilm, a pathogenic factor increasing their resistance to antibiotics. For this reason, we are looking for new substances that can neutralize bacterial cells. One of the best-known substances with such effects are silver nanoparticles. They exhibited antibacterial and antibiofilm formation activity that depended on their size, shape and the concentration used. In this review, we presented the data related to the use of silver nanoparticles in counteracting bacterial growth and biofilm formation published in scientific papers between 2017 and 2021. Based on the review of experimental results, the properties of nanoparticles prompt the expansion of research on their activity.

Chemical, Antioxidant, and Antimicrobial Properties of the Peel and Male Flower By-Products of Four Varieties of Punica granatum L. Cultivated in the Marche Region for Their Use in Cosmetic Products

We are now seeing an increase in the production of agri-food waste, which is an essential resource for the recovery of bioactive compounds that may be employed as innovative natural ingredients in cosmetics. To date, the approach to cosmetics preservation has seen a significant shift in the search for biological components that give healthier alternatives for customers and help businesses operate in an environmentally friendly manner. To achieve this goal, we studied pomegranate extracts using the peel and, for the first time, extracts from the male flowers of a wide pomegranate variety cultivated in the Marche region, specifically, the Wonderful, Mollar de Elche, Parfianka, and less-studied G1 varieties. We studied the phenol compounds profile, antioxidant capacity, antimicrobial activity, and cell viability of the obtained pomegranate extracts. The identification and quantification of phenol compounds belonging to different classes, such as hydrolysable tannins, hydroxybenzoic acid, hydroxycinnamic acid, dihydroflavonol, gallocatechin, and anthocyanins, were performed using UPLC-ESI-MS/MS. Punicalagin isomers and punicalin resulted in the most abundant polyphenols found in the peel and male flower extracts. Mollar de Elche 2020 peel extract revealed a high concentration of punicalagin A and B (7206.4 mg/kg and 5812.9), while the content of gallic acid revealed high results in the G1 and Parfianka varieties. All extracts were spectrophotometrically analysed to determine their total phenol content (TPC) using the Folin–Ciocalteu method and their antioxidant capacity (AC). In terms of the total phenol obtained by the Folin–Ciocalteu colorimetric method, Mollar de Elche 2020 extracts reported the highest TPC content of 12.341 µmol GAE/g. Results revealed that the Mollar de Elche and Wonderful 2020 peel extracts demonstrated the highest TPC and AC. Furthermore, AC results indicated that the peel extracts displayed higher AC than the male flower extract due to the high punicalagin content detected by UPLC analysis. The antimicrobial activity testing revealed that the Wonderful and G1 2020 peel extracts resulted active against Escherichia coli, while all extracts exhibited promising anticandidal activity. Additionally, the cytocompatibility was evaluated in keratinocytes HaCaT cells by testing concentrations of pomegranate extracts ranging from 0.15 to 5.00 mg/mL. Extracts were non-toxic for the cells in the tested concentration range. The acquired results may help exploit pomegranate agri-food waste products provided by the Marche region’s short supply chain for their use as an antimicrobial and antioxidant booster in the formulation of cosmetic products.

Bacterial taxa predictive of hyperpigmented skins

Background and Aims

Dark spots, brown spots, or hyperpigmented spots (HPS) are oval or irregular brown areas of skin. Their emergence is associated with dysregulation of the immune system, and may also be caused by a deficiency in stromal cell‐derived factor‐1, leading to perturbed melanogenesis and accumulation of melanosomes within neighboring keratinocytes. The skin microbiota (living microorganisms present on the surface of the skin) is known to play essential roles in maintaining skin homeostasis and in regulating the immune system. Here, we investigated whether the microbiota could play a role in the emergence of HPS.

Methods

The clinical study involved 38 European women, selected from among 74 volunteers. Participants were divided into two groups depending on the spot areas measured on their faces. The study was designed to avoid conflicting factors: both groups presented similar skin pH, hydration, transepidermal water loss, and sebum levels. The two cohorts were also age‐matched, with a mean of 29‐years‐old for both.

Results

Alpha‐diversity of the microbiota was similar for the two groups. On skins with more HPS, seven bacterial genera were identified in significantly higher proportions and included opportunistic pathogens and inflammatory bacteria. Six bacterial genera, including bacteria showing antioxidant and anti‐UV properties, were identified in significantly higher proportions on less spotted skins. Cross‐domain association networks revealed distinct co‐occurrences of genera between the two groups, suggesting nonidentical community structures and exchanges, depending on the HPS status.

Conclusion

Our results reveal specific microbiota composition and networks on skins based on HPS status. Changes could alter communication with the immune system, leading to the emergence of dark spots. As an essential part of the overall skin ecosystem, and through its interaction with the skin matrix, the skin microbiota and its maintenance could be considered a new target for skincare applications.

Cotton and Flax Textiles Leachables Impact Differently Cutaneous Staphylococcus aureus and Staphylococcus epidermidis Biofilm Formation and Cytotoxicity

Bacteria can bind on clothes, but the impacts of textiles leachables on cutaneous bacteria remain unknown. Here, we studied for the first time the effects of cotton and flax obtained through classical and soft ecological agriculture on the representatives S. aureus and S. epidermidis bacteria of the cutaneous microbiota. Crude flax showed an inhibitory potential on S. epidermidis bacterial lawns whereas cotton had no effect. Textile fiber leachables were produced in bacterial culture media, and these extracts were tested on S. aureus and S. epidermidis. Bacterial growth was not impacted, but investigation by the crystal violet technique and confocal microscopy showed that all extracts affected biofilm formation by the two staphylococci species. An influence of cotton and flax culture conditions was clearly observed. Flax extracts had strong inhibitory impacts and induced the formation of mushroom-like defense structures by S. aureus. Conversely, production of biosurfactant by bacteria and their surface properties were not modified. Resistance to antibiotics also remained unchanged. All textile extracts, and particularly soft organic flax, showed strong inhibitory effects on S. aureus and S. epidermidis cytotoxicity on HaCaT keratinocytes. Analysis of flax leachables showed the presence of benzyl alcohol that could partly explain the effects of flax extracts.

Gelidiales Are Not Just Agar—Revealing the Antimicrobial Potential of Gelidium corneum for Skin Disorders

In recent decades, seaweeds have proven to be an excellent source of bioactive molecules. Presently, the seaweed Gelidium corneum is harvested in a small area of the Portuguese coast exclusively for agar extraction. The aim of this work was to fully disclosure Gelidium corneum as a sustainable source of antimicrobial ingredients for new dermatological formulations, highlighting its potential to be explored in a circular economy context. For this purpose, after a green sequential extraction, these seaweed fractions (F1–F5) were chemically characterized (¹H NMR) and evaluated for their antimicrobial potential against Staphylococcus aureus, Staphylococcus epidermidis and Cutibacterium acnes. The most active fractions were also evaluated for their effects on membrane potential, membrane integrity and DNA damage. Fractions F2 and F3 displayed the best results, with IC₅₀ values of 16.1 (7.27–23.02) μg/mL and 51.04 (43.36–59.74) μg/mL against C. acnes, respectively, and 53.29 (48.75–57.91) μg/mL and 102.80 (87.15–122.30) μg/mL against S. epidermidis, respectively. The antimicrobial effects of both fractions seem to be related to membrane hyperpolarization and DNA damage. This dual mechanism of action may provide therapeutic advantages for the treatment of skin dysbiosis-related diseases.

Biophysical and Biological Tools to Better Characterize the Stability, Safety and Efficacy of a Cosmeceutical for Acne-Prone Skin

(1) Background: Acne is a widespread skin disease, especially among adolescents. Following the COVID-19 pandemic and the use of masks, the problem has been affecting a greater number of people, and the attention of the skin care beauty routine cosmetics has been focused on the “Maskne”, caused by the sebum excretion rate (SER) that stimulates microbial proliferation. (2) Methods: the present study was focused on the rheological characterization and quality assurance of the preservative system of an anti-acne serum. The biological effectiveness (cytotoxicity—skin and eye irritation—antimicrobial, biofilm eradication and anti-inflammatory activity) was evaluated in a monolayer cell line of keratinocytes (HaCaT) and on 3D models (reconstructed human epidermis, RHE and human reconstructed corneal epithelium, HCE). The Cutibacterium acnes, as the most relevant acne-inducing bacterium, is chosen as a pro-inflammatory stimulus and to evaluate the antimicrobial activity of the serum. (3) Results and Conclusions: Rheology allows to simulate serum behavior at rest, extrusion and application, so the serum could be defined as having a solid-like behavior and being pseudoplastic. The preservative system is in compliance with the criteria of the reference standard. Biological effectiveness evaluation shows non-cytotoxic and irritant behavior with a good antimicrobial and anti-inflammatory activity of the formulation, supporting the effectiveness of the serum for acne-prone skin treatment.

Advances in Microbiome-Derived Solutions and Methodologies Are Founding a New Era in Skin Health and Care

The microbiome, as a community of microorganisms and their structural elements, genomes, metabolites/signal molecules, has been shown to play an important role in human health, with significant beneficial applications for gut health. Skin microbiome has emerged as a new field with high potential to develop disruptive solutions to manage skin health and disease. Despite an incomplete toolbox for skin microbiome analyses, much progress has been made towards functional dissection of microbiomes and host-microbiome interactions. A standardized and robust investigation of the skin microbiome is necessary to provide accurate microbial information and set the base for a successful translation of innovations in the dermo-cosmetic field. This review provides an overview of how the landscape of skin microbiome research has evolved from method development (multi-omics/data-based analytical approaches) to the discovery and development of novel microbiome-derived ingredients. Moreover, it provides a summary of the latest findings on interactions between the microbiomes (gut and skin) and skin health/disease. Solutions derived from these two paths are used to develop novel microbiome-based ingredients or solutions acting on skin homeostasis are proposed. The most promising skin and gut-derived microbiome interventional strategies are presented, along with regulatory, safety, industrial, and technical challenges related to a successful translation of these microbiome-based concepts/technologies in the dermo-cosmetic industry.

Imbalance of the intestinal virome and altered viral-bacterial interactions caused by a conditional deletion of the vitamin D receptor

Vitamin D receptor (VDR) deficiency is associated with cancer, infection, and chronic inflammation. Prior research has demonstrated VDR regulation of bacteria; however, little is known regarding VDR and viruses. We hypothesize that VDR deficiency impacts on the intestinal virome and viral-bacterial interactions. We specifically deleted VDR from intestinal epithelial cells (VDR^ΔIEC), Paneth cells (VDR^ΔPC), and myeloid cells (VDR^ΔLyz) in mice. Feces were collected for shotgun metagenomic sequencing and metabolite profiling. To test the functional changes, we evaluated pattern recognition receptors (PRRs) and analyzed microbial metabolites. Vibrio phages, Lactobacillus phages, and Escherichia coli typing phages were significantly enriched in all three conditional VDR-knockout mice. In the VDR^ΔLyz mice, the levels of eight more virus species (2 enriched, 6 depleted) were significantly changed. Altered virus species were primarily observed in female VDR^ΔLyz (2 enriched, 3 depleted) versus male VDR^ΔLyz (1 enriched, 1 depleted). Altered alpha and beta diversity (family to species) were found in VDR^ΔLyz. In VDR^ΔIEC mice, bovine viral diarrhea virus 1 was significantly enriched. A significant correlation between viral and bacterial alterations was found in conditional VDR knockout mice. There was a positive correlation between Vibrio phage JSF5 and Cutibacterium acnes in VDR^ΔPC and VDR^ΔLyz mice. Also, there were more altered viral species in female conditional VDR knockout mice. Notably, there were significant changes in PRRs: upregulated TLR3, TLR7, and NOD2 in VDR^ΔLyz mice and increased CLEC4L expression in VDR^ΔIEC and VDR^ΔPC mice. Furthermore, we identified metabolites related to virus infection: decreased glucose in VDR^ΔIEC mice, increased ribulose/xylulose and xylose in VDR^ΔLyz mice, and increased long-chain fatty acids in VDR^ΔIEC and VDR^ΔLyz female mice. Tissue-specific deletion of VDR changes the virome and functionally changes viral receptors, which leads to dysbiosis, metabolic dysfunction, and infection risk. This study helps to elucidate VDR regulating the virome in a tissue-specific and sex-specific manner.

Red Seaweed-Derived Compounds as a Potential New Approach for Acne Vulgaris Care

Acne vulgaris (AV) is a chronic skin disease of the pilosebaceous unit affecting both adolescents and adults. Its pathophysiology includes processes of inflammation, increased keratinization, sebum production, hormonal dysregulation, and bacterial Cutibacterium acnes proliferation. Common AV has been treated with antibiotics since the 1960s, but strain resistance has emerged and is of paramount concern. Macroalgae are known producers of substances with bioactive properties, including anti-viral, antibacterial, antioxidant, and anti-inflammatory properties, among several others. In particular, red algae are rich in bioactive compounds such as polysaccharides, phenolic compounds, lipids, sterols, alkaloids, and terpenoids, conferring them antioxidant, antimicrobial, and anti-inflammatory activities, among others. Thus, the exploration of compounds from marine resources can be an appealing approach to discover new treatment options against AV. The aim of this work is to provide an overview of the current knowledge of the potentialities of red macroalgae in the treatment of AV by reviewing the main therapeutic targets of this disease, and then the existence of compounds or extracts with bioactive properties against them.

Anti-Acne Vulgaris Potential of the Ethanolic Extract of Mesua ferrea L. Flowers

Acne vulgaris is a common chronic inflammatory skin disease. In the present study, we reported the anti-acne vulgaris effect of the Mesua ferrea (M. ferrea) flower extract. The extract was evaluated for three anti-acne-causing bacteria properties including Cutibacterium acnes (C. acnes), Staphylococcus epidermidis (S. epidermidis) and Staphylococcus aureus (S. aureus). The results indicated that the M. ferrea flower extract could be considered as the bactericidal agent against S. epidermidis and S. aureus with MIC values of 0.78 and 6.25 mg mL−1 and MBC values of 1.56 and 12.50 mg mL−1 and the bacteriostatic agent against C. acnes with MIC and MBC values of 3.12 and 25.00 mg mL−1, respectively. The extract at a concentration of 25 µg mL−1 also presented potent anti-inflammatory activity with a significant decrease of nitric oxide (NO) and tumor necrosis factor (TNF)-α productions in RAW 264.7 macrophage cells stimulated by LPS. In addition, the extract showed moderate to weak anti-oxidative capacities against DPPH, ABTS, FRAP and NO assays and also showed weak anti-tyrosinase activity. M. ferrea flower extract may serve as the alternative natural anti-acne formulations.

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

Daily use of cosmetics is known to affect the skin microbiome. This study aimed to determine the bacterial community structure and skin biophysical parameters following the daily application of a skincare product on the face. Twenty-five Korean women, who used the same skincare product for four weeks participated in the study. During this period, skin hydration, texture, sebum content, and pH were measured, and skin swab samples were collected on the cheeks. The microbiota was analyzed using the MiSeq system. Through these experiments, bacterial diversity in facial skin increased and the microbial community changed after four weeks of skincare product application. The relative abundance of Cutibacterium and Staphylococcus increased, significant changes in specific bacterial modules of the skin microbial network were observed, and skin hydration and texture improved. It was suggested that daily use of skincare products could affect the microbial structure of facial skin as well as the biophysical properties of the facial skin. These findings expand our understanding of the role of skincare products on the skin environment.

Impact of pH on growth of Staphylococcus epidermidis and Staphylococcus aureus in vitro

The pH of skin is critical for skin health and resilience and plays a key role in controlling the skin microbiome. It has been well reported that under dysbiotic conditions such as atopic dermatitis (AD), eczema, etc. there are significant aberrations of skin pH, along with a higher level of Staphylococcus aureus compared to the commensal Staphylococcus epidermidis on skin. To understand the effect of pH on the relative growth of S. epidermidis and S. aureus, we carried out simple in vitro growth kinetic studies of the individual microbes under varying pH conditions. We demonstrated that the growth kinetics of S. epidermidis is relatively insensitive to pH within the range of 5-7, while S. aureus shows a stronger pH dependence in that range. Gompertz's model was used to fit the pH dependence of the growth kinetics of the two bacteria and showed that the equilibrium bacterial count of S. aureus was the more sensitive parameter. The switch in growth rate happens at a pH of 6.5-7. Our studies are in line with the general hypothesis that keeping the skin pH within an acidic range is advantageous in terms of keeping the skin microbiome in balance and maintaining healthy skin.

Human Microbiota Network: Unveiling Potential Crosstalk between the Different Microbiota Ecosystems and Their Role in Health and Disease

The human body is host to a large number of microorganisms which conform the human microbiota, that is known to play an important role in health and disease. Although most of the microorganisms that coexist with us are located in the gut, microbial cells present in other locations (like skin, respiratory tract, genitourinary tract, and the vaginal zone in women) also play a significant role regulating host health. The fact that there are different kinds of microbiota in different body areas does not mean they are independent. It is plausible that connection exist, and different studies have shown that the microbiota present in different zones of the human body has the capability of communicating through secondary metabolites. In this sense, dysbiosis in one body compartment may negatively affect distal areas and contribute to the development of diseases. Accordingly, it could be hypothesized that the whole set of microbial cells that inhabit the human body form a system, and the dialogue between the different host microbiotas may be a contributing factor for the susceptibility to developing diseased states. For this reason, the present review aims to integrate the available literature on the relationship between the different human microbiotas and understand how changes in the microbiota in one body region can influence other microbiota communities in a bidirectional process. The findings suggest that the different microbiotas may act in a coordinated way to decisively influence human well-being. This new integrative paradigm opens new insights in the microbiota field of research and its relationship with human health that should be taken into account in future studies.

Green synthesis of magnesium nanoparticles mediated from Rosa floribunda charisma extract and its antioxidant, antiaging and antibiofilm activities

Flower based nanoparticles has gained a special attention as a new sustainable eco-friendly avenue. Rosa floribunda charisma belongs to modern roses with bright yellow, red flowers with marvellous rose scent. Different methods were used for the extraction of its floral scent such as hexane, microwave, and solid-phase micro-extraction. The latter was the most efficient method for the extraction of phenyl ethyl alcohol, the unique scent of roses. In the current study, magnesium nanoparticles (RcNps) have been synthesized using Rosa floribunda charisma petals that have privileges beyond chemical and physical routs. RcNps formation was confirmed using UV-Visible (UV-Vis) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), High Resolution-Transmission Electron Microscope (HR-TEM), Field Emission-Scanning Electron Microscope (FE-SEM), Energy dispersive X-ray (EDX), X-ray Diffractometer (XRD), and X-ray photoelectron spectroscopy (XPS). HR-TEM images detected the polyhedral shape of RcNps with a diverse size ranged within 35.25-55.14 nm. The resulting RcNps exhibited a high radical scavenging activity illustrated by inhibition of superoxide, nitric oxide, hydroxyl radical and xanthine oxidase by by IC50 values 26.2, 52.9, 31.9 and 15.9 µg/ml respectively as compared to ascorbic acid. Furthermore, RcNps at concentration of 100 µg/ml significantly reduced xanthine oxidase activity (15.9 ± 0.61 µg/ml) compared with ascorbic acid (12.80 ± 0.32 µg/ml) with p < 0.05. Moreover, RcNps showed an excellent antiaging activity demonstrated by inhibition of collagenase, elastase, hyaluronidase and tyrosinase enzymes in a dose-dependent manner with IC50 values of 58.7 ± 1.66 µg/ml, 82.5 ± 2.93 µg/ml, 191.4 ± 5.68 µg/ml and 158.6 ± 5.20 µg/ml as compared to EGCG respectively. RcNps also, exhibited a promising antibacterial activity against three skin pathogens delineate a significant threat to a public health, as Staphylococcus epidermidis, Streptococcus pyogenes, and Pseudomonas aeruginosa with MIC of 15.63, 7.81, 31.25 µg/ml as compared to ciprofloxacin (7.81, 3.9 and 15.63 µg/ml). Moreover, RcNps suppressed the formation of biofilms with minimum biofilm inhibitory concentrations 1.95, 1.95, 7.81 µg/ml against the fore mentioned strains, respectively. Overall, our findings indicate that Rosa floribunda nanoparticles could be used as a leading natural source in skin care cosmetic industry.

Effects of Ulva sp. Extracts on the Growth, Biofilm Production, and Virulence of Skin Bacteria Microbiota: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes Strains

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but to date, their biological activity on skin commensal and/or opportunistic pathogen bacteria has not been reported. In this study, the effects of poly- and oligosaccharide fractions produced by enzyme-assisted extraction and depolymerization were investigated, for the first time in vitro, on cutaneous bacteria: Staphylococcus aureus, Staphylococcus epidermidis, and Cutibacterium acnes. At 1000 μg/mL, poly- and oligosaccharide fractions did not affect the growth of the bacteria regarding their generation time. Polysaccharide Ulva sp. fractions at 1000 μg/mL did not alter the bacterial biofilm formation, while oligosaccharide fractions modified S. epidermidis and C. acnes biofilm structures. None of the fractions at 1000 μg/mL significantly modified the cytotoxic potential of S. epidermidis and S. aureus towards keratinocytes. However, poly- and oligosaccharide fractions at 1000 μg/mL induced a decrease in the inflammatory potential of both acneic and non-acneic C. acnes strains on keratinocytes of up to 39.8%; the strongest and most significant effect occurred when the bacteria were grown in the presence of polysaccharide fractions. Our research shows that poly- and oligosaccharide Ulva sp. fractions present notable biological activities on cutaneous bacteria, especially towards C. acnes acneic and non-acneic strains, which supports their potential use for dermo-cosmetic applications.

The Insights of Microbes' Roles in Wound Healing: A Comprehensive Review

A diverse range of normal flora populates the human skin and numbers are relatively different between individuals and parts of the skin. Humans and normal flora have formed a symbiotic relationship over a period of time. With numerous disease processes, the interaction between the host and normal flora can be interrupted. Unlike normal wound healing, which is complex and crucial to sustaining the skin’s physical barrier, chronic wounds, especially in diabetes, are wounds that fail to heal in a timely manner. The conditions become favorable for microbes to colonize and establish infections within the skin. These include secretions of various kinds of molecules, substances or even trigger the immune system to attack other cells required for wound healing. Additionally, the healing process can be slowed down by prolonging the inflammatory phase and delaying the wound repair process, which causes further destruction to the tissue. Antibiotics and wound dressings become the targeted therapy to treat chronic wounds. Though healing rates are improved, prolonged usage of these treatments could become ineffective or microbes may become resistant to the treatments. Considering all these factors, more studies are needed to comprehensively elucidate the role of human skin normal flora at the cellular and molecular level in a chronic injury. This article will review wound healing physiology and discuss the role of normal flora in the skin and chronic wounds.

Challenging Cosmetic Innovation: The Skin Microbiota and Probiotics Protect the Skin from UV-Induced Damage

Many studies performed in the last decade have focused on the cutaneous microbiota. It has been shown that this microbiota plays a key role in skin homeostasis. Considered as “a second barrier” to the environment, it is very important to know how it reacts to exogenous aggressions. The cosmetics industry has a started to use this microbiota as a source of natural ingredients, particularly ones that confer photoprotection against ultraviolet (UV) rays. Interestingly, it has been demonstrated that bacterial molecules can block UV rays or reverse their harmful effects. Oral probiotics containing living microorganisms have also shown promising results in restoring skin homeostasis and reversing the negative effects of UV rays. Microbial-based active sunscreen compounds have huge potential for use as next-generation photoprotection products.

Effect of commonly used cosmetic preservatives on skin resident microflora dynamics

Human skin is populated by various microorganisms, the so-called microbiota, such as bacteria, viruses, yeasts, fungi, and archaea. The skin microbiota is in constant contact with the surrounding environment which can alter its eubiotic state. Recently it has been also observed that the application of cosmetic products can alter the balance of the skin microbiota. This effect may be attributed to many factors including the residual activity of the preservatives on the skin. In the present work, we studied the effect of eleven preservatives commonly found in cosmetic products on Propionibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus in vitro using 3D skin models and culture-dependent methods. Also, the effect on Histone deacetylase 3 (HDAC3) has been investigated. Among tested combinations, three resulted as the best suitable for restoring a pre-existing dysbiosis since they act moderately inhibiting C. acnes and strongly S. aureus without simultaneously inhibiting the growth of S. epidermidis. The other four combinations resulted as the best suitable for use in topical products for skin and scalp in which it is necessary to preserve the eubiosis of the microbiota. Some of the tested were also able to increase HDAC3 expression. Taking together these data highlight the role of preservatives of skin resident microflora dynamics and could provide a reference for correctly choice preservatives and dosage in cosmetic formulations to preserve or restore homeostasis of skin microbiota.

The Impact of Norepinephrine on Mono-Species and Dual-Species Staphylococcal Biofilms

The effect of norepinephrine ("NE") on Gram-negative bacteria is well characterized; however, little is known about the impact of NE on cutaneous Gram-positive skin residents, especially staphylococci. In this study, the impact of NE on monospecies and dual-species biofilms of Staphylococcus epidermidis and S. aureus model strains was investigated for the first time. Biofilms were grown in two different models (on polytetrafluoroethylene ("PTFE") cubes and glass microfiber filters ("GMFFs")) and additionally kinetic measurements of bacterial growth was performed. We have shown that NE can affect the biofilm formation of both species with a strong dependence on aerobic or anaerobic culture conditions in different models. It was shown that S. epidermidis suppresses S. aureus growth in dual-species biofilms and that NE can accelerate this process, contributing to the competitive behavior of staphylococci.

From Dysbiosis to Healthy Skin: Major Contributions of Cutibacterium acnes to Skin Homeostasis

Cutibacterium acnes is the most abundant bacterium living in human, healthy and sebum-rich skin sites, such as the face and the back. This bacterium is adapted to this specific environment and therefore could have a major role in local skin homeostasis. To assess the role of this bacterium in healthy skin, this review focused on (i) the abundance of C. acnes in the skin microbiome of healthy skin and skin disorders, (ii) its major contributions to human skin health, and (iii) skin commensals used as probiotics to alleviate skin disorders. The loss of C. acnes relative abundance and/or clonal diversity is frequently associated with skin disorders such as acne, atopic dermatitis, rosacea, and psoriasis. C. acnes, and the diversity of its clonal population, contributes actively to the normal biophysiological skin functions through, for example, lipid modulation, niche competition and oxidative stress mitigation. Compared to gut probiotics, limited dermatological studies have investigated skin probiotics with skin commensal strains, highlighting their unexplored potential.

Atrial Natriuretic Peptide Affects Skin Commensal Staphylococcus epidermidis and Cutibacterium acnes Dual-Species Biofilms

The first evidence of the atrial natriuretic peptide (ANP) effect on mono-species and dual-species biofilms of skin commensals Cutibacterium acnes and Staphylococcus epidermidis was obtained in different model systems. Elucidation of the mechanism of action of hormones on the microbial communities of human skin is an important physiological and medical aspect. Under anaerobic conditions, ANP at a concentration of 6.5 × 10-10 M inhibits the growth of S. epidermidis biofilms and stimulates the growth of C. acnes biofilms, and a lesser effect has been demonstrated on planktonic cultures. In biofilms, ANP stimulates aggregation in C. acnes and aggregate dispersion of S. epidermidis, while in S. epidermidis, ANP also stimulates the metabolic activity of cells. Analysis of dual-species biofilms has shown the dominance of S. epidermidis, while ANP increases the ratio of C. acnes biomass in the community. ANP decreases the growth rate of S. epidermidis biofilms and increases that of C. acnes. The effect of ANP is not dependent on the surface type and probably affects other targets in microbial cells. Thus, the potential regulatory effect of human ANP on skin microbe dual-species communities has been shown, and its potential has been demonstrated to change microbiota homeostasis on the skin.

Human Skin Microbiome: Impact of Intrinsic and Extrinsic Factors on Skin Microbiota

The skin is the largest organ of the human body and it protects the body from the external environment. It has become the topic of interest of researchers from various scientific fields. Microorganisms ensure the proper functioning of the skin. Of great importance, are the mutual relations between such microorganisms and their responses to environmental impacts, as dysbiosis may contribute to serious skin diseases. Molecular methods, used for microorganism identification, allow us to gain a better understanding of the skin microbiome. The presented article contains the latest reports on the skin microbiota in health and disease. The review discusses the relationship between a properly functioning microbiome and the body's immune system, as well as the impact of internal and external factors on the human skin microbiome.

Self-Nanoemulsion Loaded with a Combination of Isotretinoin, an Anti-Acne Drug, and Quercetin: Preparation, Optimization, and In Vivo Assessment

Acne vulgaris is a common skin disease that affects everybody at least once in their lives. The treatment is challenging because the stratum corneum contains rigid corneocytes surrounded by intercellular lamellae that are difficult to bypass. In the present study, we intended to formulate an effective nanoemulsion that could deliver isotretinoin (ITT) with enhanced solubility, permeability, and bioavailability across the skin. ITT can have a serious hepatotoxic effect if given too frequently or erratically. Therefore, to overcome the aforesaid limitation, quercetin (QRS), a hepatoprotective agent, was incorporated into the formulation. Initially, the ITT solubility was determined in various surfactants and cosurfactants to select the essential ingredients to be used in the formulation and to optimize a nanoemulsion that could enhance the solubility and permeability of ITT and its antimicrobial activity against Staphyloccocus aureus, which is the main microorganism responsible for acne vulgaris. The mixture design was applied to study the interactions and optimize the independent variables that could match the prerequisites of selected dependent responses. A formulation containing 0.25 g of rosehip oil, 0.45 g of surfactant (Lauroglycol-90), and 0.3 g of cosurfactant (propylene glycol) was chosen as an optimized desirable formulation. The optimized batch was loaded with QRS and evaluated for in vitro and ex vivo permeation. The in vivo hepatotoxicity was assessed through topical administration. Permeability studies confirmed the enhanced permeation percentage of ITT (52.11 ± 2.85%) and QRS (25.44 ± 3.18%) of the optimized formulation, with an enhanced steady-state flux (Jss). The in vivo studies conducted on experimental animals demonstrated superior hepatoprotective activity of the prepared optimized formulation compared with other formulations of drugs and commercially marketed products. We anticipate that this optimized ITT formulation, followed up with good clinical evaluations, can be a breakthrough in the safe treatment of acne vulgaris.