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.

If you've gone shopping for a car lately,

you might have noticed that fuel economy,

the number of miles per gallon, is slowly creeping up.

One reason is a more efficient type of fuel injection,

called gas direct injection.

It's a feature of half the new cars sold in the U.S. last year.

With that kind of engine design, you can also introduce turbocharging. That's really what it comes down to,

more engine power with a smaller engine. Naomi Zimmerman, an air quality scientist at Carnegie

Mellon University, who has, by the way, never owned a car. Probably because I did a whole PhD on engine emissions.

Here's how the two injection methods differ.

In the old standard, called port fuel injection, gas is injected into the air intake,

where it mixes with air before hitting the cylinder.

In direct injection, though, as the name implies, the fuel is injected

directly into the cylinder. It's more fuel efficient, meaning lower CO2 emissions, which will

help slow climate change. But here's the paradox. It also emits more particulate matter,

including black carbon or soot, a pollutant implicated in global warming.

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