the right kiss : does kissing make our love last longer?

In our body, we have about 10 times more microorganism cells than human cells. Especially our skin, mouth and digestive system are full of them. The body’s microorganisms have been shown to determine partner choice in some species, where one individual prefers a partner who has a similar microbiome in its body. Could it be that we kiss and touch our partners so to exchange and homogenise our microbes? If so, then this behaviour may improve our relationship. Or, more intriguingly, is our kissing and touching behaviour influenced by our microbes, to allow them to inhabit other individuals of our species? Unlikely? Well, a number of behaviour-altering effects of microorganims on humans have been reported...