If your partner’s kiss is on your lips, his microbes are too.

A passionate kiss that lasts more than 10 seconds transfers about 80 million bacteria, researchers say.  The evidence, published in the journal Microbiome, comes from 21 couples, ages 17 to 45 who made out for science.

Listen to Remco Kort, a microbiologist at the Netherlands Organisation for Applied Scientific Research in Amsterdam and lead author of the study as he speaks with NPR’s Rob Stein in this recent interview.

“It is provocative to think that we can perhaps donate beneficial microbes by an ‘oral microbiome transplant,’ ” says Joseph Petrosino, Ph.D., Diversigen Founder and Chief Scientific Officer and microbiologist at the Baylor College of Medicine.

Listen to recording.