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How Acne Bacteria Messes With Your Skin

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Some of the most powerful human experiences are universal. Love. Heartbreak. Elation. Hating acne. The microscopic jerk known as Propionibacterium acnes wreaks havoc on our skin, makes middle school harder, and can cause pain and scarring. Now scientists say we’re one step closer to understanding what makes acne so devious—and how we might conquer it. They published their findings in the journal Science Immunology.

Acne breakouts are the result of a perfect storm of disgusting conditions near the surface of your skin. Natural oils and dead cells build up around your hair follicles, creating the ideal environment for bacteria to breed. The resulting infection sets off your immune system, which leads to inflammation, redness, and those oh-so-delightful pustules on your face, neck, chest, back, or shoulders.

We knew all this already. What we didn’t know was how P. acnes, which ordinarily lives harmlessly on the skin, could multiply out of control—or how its little fortresses in your follicles send your immune system into such a panic.

Previous studies on the bacteria in the human gut have found that certain bacteria produce chemicals called short-chain fatty acids (SCFAs). These acids then block the action of an immune compound called histone deacetylase (HDAC). Suppressed HDAC can then lead to immune trouble and, from there, inflammation.

Dermatology and biochemists at the University of California, San Diego were curious to see if the same patterns would play out on and inside our skin. First, they simulated the greasy skin experience by culturing acne bacteria in Petri dishes full of blood cells or oil-producing skin cells. They ensured that the environment in the dish was smothering, starved of oxygen like the inside of a clogged follicle. Then they let it fester.

Once they had a good SCFA stew going, they ran the cultures through an RNA sequencer to see how the bacteria and cells were performing. They also applied SCFAs both on and just under the skin of lab mice to see how skin layers might react.

The team found that, as with gut cells, the skin cells could be goaded into inflammation by acne’s SCFA bullies. The same pattern bore out for the mice—but only on the topmost layer of keratinocytes, the most common type of epidermal cells. Exposing lower skin layers to acne and SCFA actually activated those cells’ immune systems, making it easier for them to fight off infection.

Adam Friedman teaches and researches dermatology at the George Washington University School of Medicine. He was unaffiliated with the study but praised the findings, telling mental_floss that they “unveil a new understanding of how P. acnes contributes to the pathogenesis of acne, but also give us more insight (and also much more work to do) with respect to the way the bacteria on our skin can change how skin works at the genetic level.”

The research goes well beyond skin problems, he says, and has “huge implications for microbiome research,” because it highlights how “our many tiny friends who live on our skin have the ability to modify how we work, which has broader implications for other inflammatory diseases.”
 
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Animals
Owning a Dog May Add Years to Your Life, Study Shows
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We've said that having a furry friend can reduce depression, promote better sleep, and encourage more exercise. Now, research has indicated that caring for a canine might actually extend your lifespan.

Previous studies have shown that dog owners have an innate sense of comfort and increased well-being. A new paper published in Scientific Reports and conducted by Uppsala University in Sweden looked at the health records of 3.4 million of the country's residents. These records typically include personal data like marital status and whether the individual owns a pet. Researchers got additional insight from a national dog registry providing ownership information. According to the study, those with a dog for a housemate were less likely to die from cardiovascular disease or any other cause during the study's 12-year duration.

The study included adults 40 to 80 years old, with a mean age of 57. Researchers found that dogs were a positive predictor in health, particularly among singles. Those who had one were 33 percent less likely to die early than those who did not. Authors didn't conclude the exact reason behind the correlation: It could be active people are more likely to own dogs, that dogs promoted more activity, or that psychological factors like lowered incidences of depression might bolster overall well-being. Either way, having a pooch in your life could mean living a longer one.

[h/t Bloomberg]

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Live Smarter
Not Sure About Your Tap Water? Here's How to Test for Contaminants
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In the wake of Flint, Michigan's water crisis, you may have begun to wonder: Is my tap water safe? How would I know? To put your mind at ease—or just to satisfy your scientific curiosity—you can find out exactly what's in your municipal water pretty easily, as Popular Science reports. Depending on where you live, it might even be free.

A new water quality test called Tap Score, launched on Kickstarter in June 2017, helps you test for the most common household water contaminants for $120 per kit. You just need to take a few samples, mail them to the lab, and you'll get the results back in 10 days, telling you about lead levels, copper and cadmium content, arsenic, and other common hazardous materials that can make their way into water via pipes or wells. If you're mostly worried about lead, you can get a $40 test that only tells you about the lead and copper content of your water.

In New York State, a free lead-testing program will send you a test kit on request that allows you to send off samples of your water to a state-certified lab for processing, no purchase required. A few weeks later, you'll get a letter with the results, telling you what kind of lead levels were found in your water. This option is great if you live in New York, but if your state doesn't offer free testing (or only offers it to specific locations, like schools), there are other budget-friendly ways to test, too.

While mailing samples of your water off to a certified lab is the most accurate way to test your water, you can do it entirely at home with inexpensive strip tests that will only set you back $10 to $15. These tests aren't as sensitive as lab versions, and they don't test for as many contaminants, but they can tell you roughly whether you should be concerned about high levels of toxic metals like lead. The strip tests will only give you positive or negative readings, though, whereas the EPA and other official agencies test for the concentration of contaminants (the parts-per-billion) to determine the safety of a water source. If you're truly concerned with what's in your water, you should probably stick to sending your samples off to a professional, since you'll get a more detailed report of the results from a lab than from a colored strip.

In the future, there will likely be an even quicker way to test for lead and other metals—one that hooks up to your smartphone. Gitanjali Rao, an 11-year-old from Colorado, won the 2017 Young Scientist Challenge by inventing Tethys, a faster lead-testing device than what's currently on the market. With Tethys, instead of waiting for a lab, you can get results instantly. It's not commercially available yet, though, so for now, we'll have to stick with mail-away options.

[h/t Popular Science]

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