What the scalp microbiome actually is
The average scalp hosts over 1,000 species of bacteria and fungi in a working balance that most people disrupt twice a week without thinking about it. The scalp is one of the oiliest surfaces on the human body, and that sebum is the primary food source for a genus of fungi called Malassezia. Malassezia is present on every human scalp. When its population stays within range, it is harmless. When it overgrows, it breaks down sebum into oleic acid, which triggers inflammation, flaking, and the condition most people call dandruff.
