How Much Bacteria Gets Transferred During Intimate Kissing?

Researchers in the Netherlands quantified how much bacteria gets transferred from one person to another during an intimate kiss (tongue on tongue action). What they found was that an average of 80 million bacteria gets transferred per 10 seconds of French kissing.

How did they come up with this figure?

Samples were obtained both before and after an intimate kiss of 10 seconds duration. One partner was  than asked to consume 50 ml of a probiotic yoghurt drink which contained organisms not normally found in the mouth, and again tongue and saliva samples were collected before and after a second intimate kiss. An estimate of the number of bacterial transfer was than determined by tracking probiotic bacterial markers.

Clearly, based on these results, one would expect (and this same study confirmed) that intimate partners have similar oral bacterial content compared to unrelated individuals.

This information may explain how kissing may result in HPV being transferred from one partner to another [link]. HPV has now been linked to being one of the most common causes of oral and throat cancer in young adults.

Of note, our office does offer the HPV spit test to see if HPV is present in the mouth/throat.

Reference:
Shaping the oral microbiota through intimate kissing. Microbiome 2014, 2:41. doi:10.1186/2049-2618-2-41