Scalp & Follicle Microbiome
The scalp and hair follicle host a characteristic microbial community including fungi (notably Malassezia species) and diverse bacteria. Sebum composition, local humidity, host immunity and product use shape this ecosystem.
Clinical relevance
- Malassezia yeast are implicated in dandruff and seborrhoeic dermatitis through inflammation related to lipid metabolism.
- Bacterial shifts have been associated with folliculitis, some scarring alopecias and possibly modulation of androgenetic alopecia in ongoing research.
Product and lifestyle effects
- Harsh surfactants, over‑use of oil or occlusive products, and improper rinsing can alter microbiome balance and contribute to irritation.
- Therapeutic shampoos (e.g., zinc pyrithione, selenium sulfide, ketoconazole) modify fungal populations and reduce flaking in susceptible people.
Research notes
- The scalp microbiome is an active research area; causation vs correlation is still being clarified for many hair and scalp conditions.