Exploring the human hair follicle microbiome

Area of Science:

• Microbiology
• Dermatology
• Human Microbiome Research

Background:

• Human hair follicles (HFs) harbor distinct microbial communities compared to the skin surface.
• The HF environment (moist, less acidic, UV-protected, immune-privileged) supports unique microbial survival.
• Understanding the HF microbiome is crucial for comprehending skin and hair physiology and pathology.

Purpose of the Study:

• To review the current knowledge of the human HF microbiome.
• To explore its physiological and pathological roles in various skin and hair conditions.
• To discuss potential therapeutic strategies targeting the HF microbiome for hair diseases.

Main Methods:

• Literature review of studies on the human HF microbiome.
• Analysis of microbial constituents (bacteria, viruses, fungi, parasites) within HFs.
• Examination of host-microbe interactions, including antimicrobial peptide production and immune responses.

Main Results:

• The HF microbiome composition differs significantly from the skin surface microbiota.
• Specific bacteria like Propionibacteria, Corynebacteria, Staphylococci, and Streptococci are key HF constituents.
• The HF microbiome is implicated in conditions such as folliculitis, acne vulgaris, hidradenitis suppurativa, and alopecia areata.

Conclusions:

• The HF microbiome plays integral roles in host health and disease.
• Host factors, including antimicrobial peptides, regulate the HF microbiome.
• Targeting the HF microbiome presents a promising avenue for managing hair and skin disorders.