Passionate Kissing Involves Transfer of 80 million Bacteria

Kissing is traditionally an expression of love but in some cases it can lead to health problems as an extended and intimate lip-lock can lead to an exchange of nearly 80 million bacteria, say experts.

Health experts say that most of these bacteria are harmless  and just take up residence in your mouth.

"Intimate kissing involving full tongue contact and saliva exchange appears to be a courtship behavior unique to humans and is common in over 90 percent of known cultures," the lead author of the study, Remco Kort, a microbiologist and principal scientist at TNO Microbiology and Systems Biology and a professor of microbial genomics at Amsterdam's VU University, said in a statement.

Doctors said that such bacteria might infact even do a good turn for some by giving no space to harmful bacteria to fester.

The study was done on 21 couples to know what  happens when couple French kiss or indulge in intimate kissing for a long time.  One partner was given a probiotic yogurt and then they were asked to kiss and then their cheeks were swabbed. Couples who reported they kissed frequently had more similar colonies of microorganisms in their saliva compared to those who did not show affection much.

The couples had to answer a questionnaire on their kissing habits and interestingly males and females had a different view on the frequency. Males reported  more kissing than females.

"We know that we obtain microbes that stay with us - many throughout our lives - in the first three years of life, but what's happening later on?" said Dr. Wenyuan Shi, a professor of microbiology at the University of California, Los Angeles, reports Today Health . "Kissing is an example of an exposure to a very large amount of bacteria. I wanted to do an experiment where I could monitor the exchange and see to what extent we are able to colonize our partners."

The study was published in  the journal Microbiome.