Listener supported WNYC Studios.

You might share a lot of things with your friends, but it turns out that you also share each other's microbiomes.

We show that we could predict your friends based on your poop.

It's Thursday, December 12th, and you're listening to Science Friday.

I'm Cyfry producer, D. Peter Schmidt.

The microbiome is a super complex network made up of trillions of microbes that live inside and

on our bodies. It helps us digest food, protects us from diseases, and depending on what

species of bacteria you have, your microbiome could impact how likely you are to develop arthritis

and depression. Scientists know that your microbiome is partially shaped by your environment and the people

you spend time with, but they haven't had a lot of clarity on how exactly your social networks

outside of your home and family impact your microbiome

makeup. But new research shows that we're more connected to our friends than you may think.

Here's Ira Flato with more.

To learn more, my next guest and his team mapped close to 2,000 social connections in isolated

villages and compared the microbiomes to see just how exactly their social

closeness impacted their gut bacteria. Their research was published in the journal Nature.

Here to tell us more is Dr. Nicholas Christakis, a sociologist and physician at Yale University

where he directs the human nature lab. He studies the biology of human social interactions

and was an author on that research. Welcome back to Science Friday. Thank you so much for

having me back, Ira. Nice to have you back. What were the big questions you wanted to answer in this

study? Well, overall, we wanted to understand where does the microbiome in our bodies, in our guts

in particular, come from?

...