Importance of Microbiomes on skin: mites (Introduction)

by David Turell , Saturday, March 16, 2024, 19:47 (251 days ago) @ David Turell

Both types here to stay:

https://www.nationalgeographic.com/premium/article/face-mites-arachnids-human-skin-pore...

"At this moment, hundreds or thousands of tiny eight-legged animals are nestled deep in the pores of our faces—my face, your face, your best friend’s face, and pretty much every other face you know or love. In some sense, they’re our closest companions.

"These animals are mites—tiny arachnids, related to spiders and ticks. They’re too small to see with the naked eye, and too small to feel as they move about. Not that they move much: Face mites are the ultimate hermits, likely living most of their lives head down inside a single pore. In fact, their bodies are shaped like the inside of a pore, evolution having long ago reduced them to narrow plugs topped with eight absurdly tiny legs.

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"Mites have been unfairly blamed for a variety of skin conditions, the researchers reported in the journal Molecular Biology and Evolution. Instead of being harmful parasites, the scientists say, Demodex genetics suggest that the mites are evolving toward a symbiotic relationship with humans. In fact, this could be their ultimate undoing. As the mites become more dependent on their human hosts, they’re losing the genetic diversity their species needs to survive. At some point, the researchers write, “the survival of the species over evolutionary time might be in question.”

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"Thoemmes has one other way to find face mites: using their DNA. When Dunn’s group analyzed the DNA in sebum samples, they found face mite DNA in every single person tested over the age of 18 (versus just 14 percent of people via face scraping). In 2014 they published evidence that face mites are ubiquitous in humans. Further DNA research has revealed that face mites have evolved so closely with their human hosts that at least four distinct lineages of mites mirror our own—those with European, Asian, Latin American, and African ancestry.

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"Now, though, our view of face mites is shifting. If virtually everyone has them, either we’re all infested or that’s not the right word to describe their presence. Even their link to rosacea might not be what it first appeared to be, Thoemmes suggests: What if it’s the other way around? Maybe the inflammation and increased blood flow related to rosacea create conditions favorable to face mites. In other words, larger face mite populations could be a symptom of rosacea, not a cause.

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"What’s more, as science has come to view the human body as an ecosystem—home to diverse microscopic flora and fauna—it’s not clear that Demodex mites should be considered harmful parasites. Mites might even help us, as do the “good” microbes that live in our guts; they could be eating harmful bacteria in our pores, along with dead skin and sebum, or secreting antimicrobial compounds. We and our mites might be in a symbiotic relationship: We feed them pore gunk, they help with the housekeeping."

Comment: I guess we could call this our beneficial insectome! Ladies who deep-clean pores on a regular basis may be creating more harm than good.