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This is scientific American's 60 Second Science. I'm Christopher Intagata.

There's a lot of advertising mythology about what causes Dandruff like this.

Here's why clean scalp is important. Your hair roots must breathe. Or there's trouble, deep trouble.

Dandruff. Dandruff itself is actually a very, very complicated condition.

Microbiologist and molecular biologist Barry Murphy, of Unilever in the UK,

says Dandruff is a perfect storm of flakiness involving your fungal

microbiome the health and oiliness of the skin on your scalp even weather.

His team set out to investigate the microbial component. They sequenced DNA from the heads of people with healthy

hair and from others with dry dandruff scalps, none of whom had used anti-dandruff shampoo within the last six months.

As previous studies have found, they spotted ten times as much of a type of fungus called Malaetsia

on dandruffy scalps versus the healthy cohort.

But they also found that populations of a bacterium called Staphylococcus capitis spiked on flaky scalps.

Really, really interestingly, we found that there was approximately a hundred times more of this bacteria on a dry or a dandros scalp than there was on a healthy scalp.

But it's still a mystery why it's there or what it's doing. The results are in the journal

Plus 1. Murphy's employer Unilever makes its own anti-Dandruff products so this could be

useful information someday but rather than just zapping scalp fungi

with antifungal compounds,

like most of today's anti-dandruff shampoos do,

Murphy says the goal might be to make a more gentle product.

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