Laser capture microdissection as a method for investigating the human hair follicle microbiome reveals region-specific differences in the bacteriome profile

Abstract

Objective Human hair follicles (HFs) are populated by a rich and diverse microbiome, traditionally evaluated by methods that inadvertently sample the skin microbiome and/or miss microbiota located in deeper HF regions. Thereby, these methods capture the human HF microbiome in a skewed and incomplete manner. This pilot study aimed to use laser-capture microdissection of human scalp HFs, coupled with 16S rRNA gene sequencing to sample the HF microbiome and overcome these methodological limitations. Results HFs were laser-capture microdissected (LCM) into three anatomically distinct regions. All main known core HF bacterial colonisers, including Cutibacterium, Corynebacterium and Staphylococcus, were identified, in all three HF regions. Interestingly, region-specific variations in α-diversity and microbial abundance of the core microbiome genera and Reyranella were identified, suggestive of variations in microbiologically relevant microenvironment characteristics. This pilot study therefore shows that LCM-coupled with metagenomics is a powerful tool for analysing the microbiome of defined biological niches. Refining and complementing this method with broader metagenomic techniques will facilitate the mapping of dysbiotic events associated with HF diseases and targeted therapeutic interventions.

Mechanical epilation exerts complex biological effects on human hair follicles and perifollicular skin: An ex vivo study approach

“…Finally, the range of biomarkers studied should be greatly expanded, including wound healing/trauma-associated products of genes that have recently been reported to be associated with androgenetic alopecia [169] or that are known to regulate wounding-induced HF neogenesis in adult mice [170]; moreover, indicators of long-term HF and skin wounding memory [171], especially after repetitive epilation, could be studied. In addition, the impact of epilation on human HF innervation [172], neuroendocrine signalling [173][174][175], and the human HF microbiome [165,176] remains to be investigated, and our hypothesis-driven protein−/celllevel data should be complemented with hypothesis-free transcriptomic data at various time points post-epilation.…”