French Kisses Give 80 Million Healthy Bacteria

A study in the journal Microbiome found that a ten-second French kiss can spread 80 million bacteria between mouths. 80 million may sound scary, but these bacteria may actually benefit your body.

Scientific Research in the Netherlands required 21 couples to participate in a study on French kissing. Their tongues were swabbed and saliva collected before and after a timed ten-second French kiss.

Interestingly, they found the bacteria on the tongues of couples were more similar than of two strangers. “Apparently, being with somebody for an extended amount of time and having a relationship leads to a similar collection of bacteria on the tongue,” said Professor Remco Kort, lead researcher, Netherlands Organisation for Applied Scientific Research.


Dry kisses are not as healthy.

To find how similar the shared bacteria were, the researchers did one more test. One person in the couple drank a probiotic yogurt drink containing bacteria called Lactobacillus and Bifidobacteria and waited awhile. Then, the couple shared a 10-second, French kiss. The researchers took a sample of the bacteria in the mouth of the partner who hadn’t had any probiotic yogurt. What the researchers found was that the volume of bacteria transferred to the other partner was on average 80 million bacteria!

Quantity and Quality of Kisses Make a Difference

The research team also found out through questionnaires that the more often a couple kisses, the more bacteria they share. Dry, prudent kisses only transfer 1,000 bacteria and a French kiss will give millions of bacteria!

Even though bacteria in the saliva changed quickly after a kiss, the bug populations on the tongue remained more stable.

“French kissing is a great example of exposure to a gigantic number of bacteria in a short time. While 80 million bacteria being transferred in just one kiss sounds scary, it is in fact probably a good thing, acting as a form of immunization and building resistance from exposure to different microorganisms,” says Professor Remco Kort.

 “If you look at it from this point of view, kissing is very healthy,” added Prof Kort.

Would you like to know how much bacteria you and your partner are sharing? There is a “Kiss-o-meter” set up in Amsterdam based on this research that will rate your kisses at Micropia. They will give you a read out of the microorganisms you’ve exchanged.


Not Enough Kisses In Your Life?

Maybe you and your partner need a little help with healthy food aphrodisiacs like honey, almonds or chocolate. Learn how to make chocolate treats without the sugar at the Healthy Chocolate Project.

If you’re not kissing anyone… not to worry. There are many ways to get probiotics and prebiotics into your diet and boost your immune system in general.

Most fruits and vegetables contain a lot of fiber, so they provide a healthy bacterial environment in your digestive tract. Ghee is particularly good at feeding healthy bacteria and your immune system.


Richard B
Richard B1 months ago

thank you

Kelly S
Past Member about a year ago


natasha p
.about a year ago


Siyus Copetallus
Siyus Copetallus2 years ago

Thank you for sharing.

Muff-Anne York-Haley


Steve McCrea
Steve McCrea3 years ago

More proof that bacteria are not to be feared in the vast majority of cases. Take that, cleaning freaks!

Beryl Ludwig
Beryl Ludwig3 years ago

thank you. One more reason to kiss even more!

Connie O.
Connie O3 years ago


Janis K.
Janis K3 years ago

Thanks for sharing

Marianne R.
Marianne R3 years ago

Just in time....