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Love May Be Linked To The Bacteria In Our Mouths

Study shows the role of the microbiome in romantic attraction

Photo credit: Robert / Flickr

A man and a woman kiss in this undated photo.

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Did you know you may be attracted to a romantic partner's microbes?

It's possible, according to Dr. Bill Miller, author of "The Microcosm Within: Evolution and Extinction in the Hologenome," a book examining immunological factors in evolution.

He told KPBS Midday Edition that a study found couples who kiss "deeply and intimately and often" not only share microbes — an expected and beneficial outcome — but also were attracted to each other's microbes before they became a couple.

"When they tested out the partners to see who was really attracted to whom, the people whose oral microbiomes, the sets of microbes inside the mouth, tended to match much more than random between the people who found themselves attracted," he said. "How could that possibly be? What we know is these microbes don't just exist, they're giving off metabolic products, they have a life cycle of their own."

He said those metabolic products make their way to our brains and influence our attraction.

"It sounds creepy, but it's good," he said.

A microbiome describes the population of microbes — all of the living organisms that inhabit our bodies, including healthy and unhealthy bacteria — that each person carries.

"You look in the mirror and see yourself, and you have to think you're one being," Miller said. "But nature doesn't see you that way."

He said the majority of cells you see when you look in the mirror aren't actually your own, but are instead microbes.

"We cannot live without them," he said. He said new research is finding the links between our microbiomes and our metabolism, blood sugar and our immune system.

And, he said, our relationships.

"What we're finding out is that they're giving us hidden cues," Miller said. "This is still new research, but what we're finding is our microbes are giving off chemical signals that determine our reaction to social circumstances and even romantic entanglements."

Sci-Q is a monthly series on Midday Edition, and KPBS listeners are invited to join in on the fun. If you have a scientific topic you'd like to explore or a question you want answered, contact us on Twitter @KPBSMidday using the hashtag #Sci-Q.


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