Hair graying and loss are prominent aging phenotypes that affect the physical beauty and quality of life in most elderly population. Although extensive efforts have been made to understand the mechanism of hair aging, the exposure factors and the cellular activities that underlie the process of hair aging are still largely unknown. Recently, increasing progression points to potential involvement of the cutaneous microbiome in hair aging: 1) the microbiome of the hair follicle is crucial for maintaining the stem cell niche and hair growth; 2) the microbiome dysbiosis has been proved as an additional hallmark and biomarker of aging; 3) the abnormal skin microbiome has been implicated to play a major role in several environmentally determined skin diseases or hair follicle-associated disease such as hidradenitis suppurativa.

This project aims to investigate the changes that occur in the hair follicle skin microbiome as hair ages using microbiome sequencing in patients with hair graying/loss and healthy controls, and by using Single-cell RNA sequencing to explore how this complex relationship between the skin microbiome and cellular activities in the hair follicle can contribute to hair graying and loss. Our findings may provide novel data on the microbiological diversity of the skin, uncover the involvement of follicular skin microbiota in the process of hair aging, and may lead to the development of innovative treatments for hair graying and loss.

According to our previous studies, there are significant differences in facial microbial colonies, especially in the relative abundance of Malassezia among healthy individuals at different altitudes. The disease diversity of seborrheic dermatitis is positively correlated with the relative abundances of Malassezia, Staphylococcus, and Corynebacterium. However, there is still a lack of evidence on the impact of environmental factors, especially altitude, on shaping the seborrheic dermatitis facial microbiome and skin barrier function.

We would like to recruit 80 patients with seborrheic dermatitis from highlands and lowlands in China. Skin swabs were collected from both affected and unaffected areas of the participants. All samples were subjected to ITS1 and V3V4 16S rRNA region amplicon sequencing and metabolomic analysis. We aim to observe the impact of altitude on the microbiome and skin barrier function in seborrheic dermatitis and provide clinical research data for further investigation into the pathogenesis of this disease.