The love season is coming and lovers not only share feelings, but also bacteria ! Certainly, at first, all this does not really seem glamorous. However, kiss consolidates our immune system.

Dutch scientists were the first to focus on the consequences of a kiss on the oral microbiota. Our mouth houses to about 700 varieties of bacteria and this microbiome is influenced by genetics, age, diet… and by the entourage !

Proper to the human species and common in 90% of all known cultures, the “intimate kiss involves contact of all tongue and an exchange of saliva appears as a seductive behavior” according to Remco Kort, who led the study.

21 couples were enrolled in the study. They fulfilled questionnaires about their habits, duration and frequency of their intimate kisses. Samples were also collected on the tongue and saliva to analyze and compare their composition. In an experiment, one of the partners has to consume a beverage with probiotic bacteria comprising Lactobacillus and Bifidobacterium, and then exchange a kiss with his/her partner.

From these different items, the researchers showed :

  • after one kiss, the amount of probiotic bacteria was tripled in the saliva of the recipient partner ;
  • kissing 10 seconds led to exchange 80 million bacteria ;
  • when couples kiss more than nine times a day, their salivary microbiota became identical.

Little by side : 74% of men reported a higher frequency of kissing their partner. On average, a man declared 10 kisses a day against 5 in women.

This bacterial sharing strengthening our immune defenses would be very healthy !

LC