November 27, 2024
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Your friends shape your microbiome, and so do their friends
Study of nearly 2,000 people living in remote villages in Honduras reveals who is spreading gut microbes to whom
Friends share more than food when they dine together.
A shared meal, a kiss on the cheek: these social actions bring people together, and also unite microbiomes. The more people interact, the more the composition of their intestinal microorganisms is similareven if people don’t live in the same house, a study shows.
Research has found that too a person’s microbiome it consists not only of their social contacts, but also of the connections of social relations. The work is one of several studies that suggest that health conditions can be shaped by the transmission of the microbiome between individuals, but not only. diet and other environmental factors that affect gut flora.
In trying to understand what shapes a person’s microbiome, social interactions “are a piece of the puzzle that I think has been missing until recently,” says microbiologist Catherine Robinson of the University of Oregon in Eugene, who was not involved in the work. .
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The study was published in nature on November 20.
Mine is yours
The research has its roots in research published nearly 20 years ago that investigated how obesity spreads on social media. Some viruses and bacteria found in it the gut microbiome they are known to change a person’s risk of obesityand social scientist Nicholas Christakis asked whether friends pass these microbes to each other in addition to influencing each other’s eating habits. “This was the heart of an idea I couldn’t let go of,” says Christakis, who lives at Yale University in New Haven, Connecticut.
Since then, several publications have suggested so social interactions shape the gut microbiome. Christakis and his colleagues traveled to the jungles of Honduras to add to this emerging literature. There, they mapped social relationships and analyzed the microbiomes of people living in 18 isolated villages, where interactions are mostly face-to-face and people have minimal exposure to processed foods. antibiotics, which can change the composition of the microbiome.
“It was a huge undertaking,” says Christakis, because the team had to set up shop in a remote location, then ship the samples back to the United States for processing.
Spouses and individuals living in the same household share 13.9% of gut microbial strains, but those who don’t share a roof but spend free time together also share 10%, the researchers found. Conversely, those who live in the same town but do not tend to spend time together share only 4%. There is also evidence of chains of transmission: friends of friends share more strains than would be expected by chance.
The results add depth to scientists’ understanding which forms the microbiomepartly because the team looked at subspecies of gut microbes, says microbiologist Mireia Valles-Colomer of Pompeu Fabra University in Barcelona, Spain, who was not involved in the work. Social contacts may share the same microbial species by chance, but they are much more likely to share the same strains unless they have passed it on to each other.
Rethinking Transmission
Research like this is “completely changing the way we think,” suggesting microbiome-linked risk factors for conditions such as high blood pressure and depressionit could spread from one person to another through their microbiomes, says computational biologist Nicola Segata at the University of Trento in Italy. Segata was not involved in the current work, but has worked with Valles-Colomer and members of Christakis’s group on similar studies in the past.
For depression, which can be difficult to treat, combining existing therapies with microbiome-targeting treatments may improve care, Valles-Colomer says.
But people shouldn’t avoid social interactions for fear of “catching” other people’s microbiomes. Social interactions can and do propagate healthy microbiome components many other benefits. As Valles-Colomer says, “Close contacts are not bad for us. On the contrary, they are beneficial!”
This article is and was reproduced with permission first published November 20, 2024.
