Understanding the human body is a team effort. That's where the Yachtel group comes in.

Researchers at Yachtolt have been delving into the secrets of probiotics for 90 years.

Yacold also partners with nature portfolio to advance gut microbiome science through the global grants for gut health, an investigator-led research program.

To learn more about Yachtolt, visit yawcult.co.

.j.p. That's Y-A-K-U-L-T.C-O.J-P. When it comes to a guide for your gut, count on Yacult.

This is Scientific American's 60-second science. I'm Larry Greenmire.

When you install an app on your smartphone, you're often asked whether you'd like to share your list of contacts with that app.

That might be a convenient way to connect with friends and family likewise using, say, Instagram or WhatsApp,

but it also means you're giving away their personal information to the app developers.

And that personal info could end up being used to create so-called shadow profiles of your contacts,

even if they don't use that app or social media service.

Shadow profiles emerged as a potential problem in 2011 when an Ireland-based advocacy group accused Facebook of gathering information on non-users, including names, email addresses, phone numbers, and physical addresses.

The following year, researchers showed that social network companies such as Facebook could use machine learning to pretty accurately predict whether two non-members

known by the same member also know one another.

Not exactly Big Brother, but a recent study in the journal Science Advances raises the stakes.

In that work, David Garcia, chair of systems design at the SITAC University, ETH Zurich,

used the social network member's personal information

to infer relationship status and sexual orientation of the member's contacts who did not have

their own user accounts on that social networking site. He was able to do that, using, of all things,

data from the now-defunct Friendster social networking site. He says he chose those two attributes, relationship status and sexual orientation, because

they can carry important privacy consequences and were both available in the Friendster data set.

Garcia is careful to point out that he didn't prove that shadow profiles exist, just that they

...