Predominant niche-based process assembly of megacity skin microbiomes results in a relatively fragile microbial network.

We examined differences in the skin microbiome of two separate age groups to find key microbial and skin physiological indicators associated with aging. We recruited healthy Korean women 19–28 years old (Y-group) and 60–63 years old (O-group) and evaluated their cheek and forehead skin microbiome, including bacteria and fungi. The microbiome was significantly different by age group, with bacterial and fungal communities displaying higher alpha-diversity in the O-group than in the Y-group. We identified amplicon sequence variants affiliated with Cutibacterium and Lactobacillus and fungi Malassezia restricta as microbial biomarkers showing significant differences between the Y and O-group. There are more microbial communities and metabolic processes related to skin health in the Y-group than in the O-group, and there are more microbial interactions to increase the stability of the network structure of the skin. Skin physical metadata, including transepidermal water loss and sebum content, differed by two age groups. The crucial skin microbes, skin physical parameters, and microbial network found through this research will be useful key indicators in associating skin aging and skin microbiome research.

Acne vulgaris, commonly known as acne, is the most common skin disorder and a multifactorial disease of the sebaceous gland. Although the pathophysiology of acne is still unclear, bacterial and fungal factors are known to be involved in. This study aimed to investigate whether the microbiomes and mycobiomes of acne patients are distinct from those of healthy subjects and to identify the structural signatures of microbiomes related to acne vulgaris. A total of 33 Korean female subjects were recruited (Acne group, n = 17; Healthy group, n = 16), and microbiome samples were collected swabbing the forehead and right cheek. To characterize the fungal and bacterial communities, 16S rRNA V4-V5 and ITS1 region, respectively, were sequenced and analysed using Qiime2. There were no significant differences in alpha and beta diversities of microbiomes between the Acne and Healthy groups. In comparison with the ratio of Cutibacterium to Staphylococcus, the acne patients had higher abundance of Staphylococcus compared to Cutibacterium than the healthy individuals. In network analysis with the dominant microorganism amplicon sequence variants (ASV) (Cutibacterium, Staphylococcus, Malassezia globosa, and Malassezia restricta) Cutibacterium acnes was identified to have hostile interactions with Staphylococcus and Malassezia globosa. Accordingly, this results suggest an insight into the differences in the skin microbiome and mycobiome between acne patients and healthy controls and provide possible microorganism candidates that modulate the microbiomes associated to acne vulgaris.

Sensitive skin (SS) syndrome is a globally widespread, self-diagnosed discomfort characterized by subjective complaints. Although the skin microbiome is considered important in skin health, the relationship between the skin microbiome and skin sensitivity is still unknown. Here, we aimed to (i) investigate whether the microbiome and mycobiome of SS are distinct from those of non-sensitive skin (NS), and (ii) define the characteristics of the skin microbiome associated with skin sensitivity. A total of 42 Korean women subjects were recruited (SS, n = 23; NS, n = 19) and the microbiome/mycobiome of their right facial cheeks were analyzed. We identified the differential microbiome and mycobiome structures between SS and NS. The mycobiome of SS was more phylogenetically diverse than that of NS. Lactobacillus and Mucor racemosus were more abundant on SS than NS, whereas Malassezia restricta was less abundant. Interestingly, both skin microbiome and mycobiome varied according to the perceived skin sensitivities of the subjects. This study suggests that the skin microbiome and mycobiome are associated with skin sensitivity. Accordingly, it lays the foundation for developing microbiome-based cosmetics or remedies for individuals suffering from SS syndrome.