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.

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

This is Scientific American's 60-second science. I'm Christopher in Taliatta.

Rome wasn't built in a day, and neither was the Roman subway system.

Underground work is slow going because construction crews often unearthed mosaics, frescoes, marble.

And a few years ago, they found the wooden foundations of a luxurious porch from a Roman villa.

So local archaeologists called in Mauro Bernabe of the National Research Council of Italy.

He's a dendrochronologist, someone who analyzes tree rings, which give age and environmental info.

We have to study wood because he's full, really full of information.

Bernoube and his team found that the wooden planks were oak,

but the woods' origin was harder to determine,

so they compared the tree rings and the oak planks

to those available in libraries of tree rings

that contain timber from all over Europe.

And they found a match for the Roman lumber

from the Jura region of eastern France,

more than 600 miles away.

The researchers also determined that the French timber was harvested in about 40 to 60 C.E.

And some of it came from trees already up to 300 years old when they were felled.

...