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.

Yachtold 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.j. That's y-A-K-U-L-T.C-O.jp. When it comes to a guide for your gut, count on Yacult.

For Scientific American Science quickly, I'm Rachel Feltman.

If you're familiar with John Green, you might associate him with best-selling young adult novels like The Fault in Our Stars or with the Healthy on Days of Early YouTube vlogging.

But a few years ago, John became obsessed with a topic that you might find surprising, tuberculosis.

His new book, Everything is Tuberculosis,

comes out on March 18th. He's here today to tell us how tuberculosis has shaped our world,

and why, even though it's now curable, it remains our planet's deadliest infectious disease.

John, thanks so much for joining us to chat today.

Oh, thanks for having me.

Tell us about your new book, I think, for some folks who are familiar with your work, they might be surprised to hear that you've been so interested in tuberculosis.

Yeah, it's certainly a change from writing young adult novels.

I became obsessed with tuberculosis in 2019 when I visited a TB hospital in Sierra Leone and met a boy living with tuberculosis who shared a name with my son, Henry.

Through my friendship with Henry, I really started to think differently about the disease and started to think

that the disease in some ways is an exemplification of everything that's wrong with the way we've

distributed resources and technology over the last 75 years, because tuberculosis has been

curable since the 1950s, but it's still our deadliest infectious disease.

And I just think that's such an indictment of the systems that we've built to improve human health.

Absolutely. Well, and for listeners who might be surprised to hear that it's the deadliest infectious disease, can you give us a sense of the scope of tuberculosis right now?

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