When you share a kiss, are you also sharing bacteria?
Our mouths harbour a multitude of bacteria, as many as 700 different varieties. Given this fact, a team of researchers decided to look into what bacteria are exchanged when people kiss. The results were published in Microbiome 1 , revealing that a kiss lasting for 10 seconds represents over 80 million bacteria being exchanged.
The researchers also noticed that couples who kiss 9 times a day have practically identical saliva. They go on to hypothesise that this could help these individuals digest the same type of food and develop better resistance to shared infections.
They report that "intimate kissing involving full tongue contact…appears to be an adaptive courtship behaviour unique to humankind and is common in over 90% of known cultures”. So, now we know about the health benefits of kissing, why hold back? Pucker up!
1) Remco KortEmail author, Martien Caspers, Astrid van de Graaf, et al. Shaping the oral microbiota through intimate kissing. Microbiome 2014;2:41.