According to Dutch scientists, a 10-second kiss could result in the transfer of around 80 million bacteria.
The research team monitored the kissing behaviour of 21 couples and discovered that those who kissed nine times per day were at most risk of sharing salivary bugs.
Studies show that the mouth carries more than 700 varying types of bacteria, but according to the report, some are transferred more easily than others.
A team based at the Netherlands Organisation for Applied Scientific Research (TNO) questioned 21 couples about their kissing habits, including the frequency of their kissing during the last year and when they last shared a kiss.
They then took bacterial samples from the tongues of the volunteers, as well as saliva before and after a timed 10-second kiss. One member of the couple was then asked to drink a probiotic drink, which contained an easily identifiable combination of bugs.
Scientists were able to find the volume of transferred bacteria after the second kiss, and found an average of 80 million bacteria transferred during one 10-second kiss. Although bacteria in the saliva appeared to change very quickly in response to a kiss, the number of bugs on the tongue remained stable.
The leader of the research, Professor Remco Kort, said French kissing is a perfect example of exposure to a massive amount of bacteria in a very short space of time.
However, it was found that only some of the bacteria transferred during the kiss remained on the tongue.
He said that further research should consider the properties of the bacteria and the tongue which contribute to the sticking of the bacteria. He added that this type of investigation would aid in the design of future bacterial therapies and aid those suffering with troublesome bacterial issues.
The Dutch scientists worked hand-in-hand with Micropia in Amsterdam, the first microbe museum in the world.
During a newly opened exhibition, couples are asked to share a kiss and can obtain an instant analysis of the bacteria they exchanged.
A large number of researchers are assessing microbiome which is an ecosystem containing around 100 trillion micro-organisms which survive in and on the human body. According to scientists these population could be vital for health and in the prevention of disease.
Image Credit: Pedro Ribeiro Simões