SC Connecticut News

A recent study led by Yale University reveals that social connections can influence the composition of a person's microbiome. Published in the journal Nature, the research explores how different types of relationships, including friendships, affect the microorganisms inhabiting individuals' gastrointestinal tracts.

The study involved mapping the social networks and collecting microbiome data from 1,787 adults residing in 18 isolated villages in Honduras. The researchers identified 2,543 microbial species and 339,137 strains among participants. They discovered that people connected through various non-familial and non-household relationships exhibited similarities in their microbiomes beyond what might occur by chance.

Francesco Beghini, co-lead author and postdoctoral associate at Yale's Human Nature Lab, noted: “We found substantial evidence of microbiome sharing happening among people who are not family and who don’t live together, even after accounting for other factors like diet, water sources, and medications.” He added that “microbiome sharing was the strongest predictor of people’s social relationships in the villages we studied.”

While spouses and household members shared the most microbes, elevated levels were also observed among friends and second-degree connections. The frequency of interactions such as shared meals or greetings like handshakes was linked to increased microbial sharing.

The study also showed less microbial sharing between villagers without social ties and even less between those from separate villages. Two years later, a follow-up with a subset of 301 participants confirmed that socially connected individuals had become more microbially similar over time.

Jackson Pullman, another co-lead author from Yale College’s class of 2023, explained: “Think of how different social niches form at a place like Yale... Our study indicates that the people composing these groups may be connected in ways we never previously thought.”

The findings have both negative and positive implications. They suggest certain diseases associated with the microbiome could be more communicable than believed but also highlight potential health benefits transferable through social networks.

Nicholas Christakis, senior author and Sterling Professor at Yale's Faculty of Arts and Sciences said: “My lab is very happy to publish this paper... phenomena like obesity might spread not only by social contagion but also by biological contagion.”

This research was supported by funding from the NOMIS Foundation and Rothberg Catalyzer Fund.