Kissing your partner far more than a show of affection - you're also sharing the 80 million bacteria that live in your mouth, scientists say.
Research shows that when couples kiss for at least 10 seconds their salivary microbiota becomes similar due to the transfer of microbes from one mouth to the other.
The findings come from a new study that investigated the 'effects of intimate kissing on the oral microbiota.'
Other studies have found that every person has anywhere from 100 to 200 species of microbes living in their mouth, but most are harmless and actually protect us from infections.
'Interestingly, the current explanations for the function of intimate kissing in humans include an important role for the microbiota present in the oral cavity, although to our knowledge, the exact effects of intimate kissing on the oral microbiota have never been studied,' said Remco Kort, from Netherlands Organisation for Applied Scientific Research.
'We wanted to find out the extent to which partners share their oral microbiota, and it turns out, the more a couple kiss, the more similar they are