Your friends may not know whom you've been kissing. But the bacteria can tell the tale.
Intimate kissing can exchange tens of million of bacteria in a matter of seconds. As a result, partners tend to have a similarity in the bacteria found in their mouths.
The study examined saliva prior to a kissing experiment. Then the researcher introduced a safe bacteria to one partner via a probiotic yogurt. After kissing just a total of two times, that bacteria was detected on the tongue of the other partner.
Kissing is not the only way that bacteria are exchanged between partners, according to the researcher. Examples might include similar diets or using the same toothpaste.
In general, the examination of saliva samples found that there was more similarity between partners that kissed regularly than those who did not kiss, or did not kiss frequently. Put simply, the more partners kiss each other, the greater the similarity of the bacteria in their saliva.
The study was conducted by Micropia and the Netherlands Organization for Applied Research.