Kissing: A Bacterial Exchange

A new study reveals that a passionate, intimate kiss can swap almost 80 million bacteria between the partners involved. And the more frequent the kissing, the more similar the partners’ oral bacteria can become.

The mouth is home to over 700 different varieties of bacteria, and several factors are key in shaping your overall oral microbiome (the collection of microorganisms present in your body). Diet, age, and genetics were thought to be the largest deciding factors in bacteria growth, but now scientists are realizing that your romantic partners may play a key role in this as well.

A scientist in the Netherlands, along with his team, sampled 21 romantic couples, polling how frequently they kissed intimately, and for how long. Then, they had one person from each of the couples drink a probiotic beverage containing very specific strains of bacteria; Lactobacillus and Bifidobacteria. The couples were then encouraged to kiss passionately.

After a 10-second passionate kiss, the quantity of the test probiotics rose in the other individual’s mouth by almost 300%. A total of almost 80 million bacteria were swapped in those 10 passionate seconds via saliva.
Couples who kiss passionately at least nine times a day are shown to have significantly similar salivary microbiota. However, the salivary bacterial exchange is only temporary. Couples who kiss with more tongue are more likely to have similar tongue microbiota. These tongue bacterial collections stick around much longer as they are able to thrive on the tongue’s surface and spawn.

Originally, it was believed that passionate, tongue kissing (found in 90% of human cultures) was used to “sample” the partner’s saliva and test for chemical taste cues, screening them as their potential mate. But now scientists are seeing that passionate kissing could have more benefits.

If you are concerned with bad bacteria in your microbiome, feel free to make an appointment with your friendly Valencia dentist to ask any questions today.