Kissing isn’t just a romantic gesture; it’s a complex microbial exchange that may profoundly impact how we fall in love. New research suggests that swapping saliva – and the tens of millions of microbes within it – could play a more significant role in affection and intimacy than previously understood.
The Microbial Exchange of Intimacy
Microbiologist Remco Kort from VU Amsterdam proposes that the exchange of oral bacteria during deep kissing isn’t just a side effect of intimacy, but a potential driver of it. The human mouth is the second-most diverse bacterial community in the body, and sharing microbes may have unexpected effects on our health, hormones, and even our feelings of love.
How Kissing Changes Your Biology
When humans kiss, they aren’t just sharing affection; they’re inoculating each other with oral microbes. This isn’t merely a biological quirk; it could be a form of “oral vaccination,” offering surprising health benefits. The transfer of bacteria can alter the gut microbiome, influence hormone levels, and even affect brain function. Over time, couples who kiss frequently develop increasingly similar oral bacterial communities.
The Feedback Loop of Love & Health
Kort’s research suggests that this microbial similarity creates a positive feedback loop: love and affection improve health, while good health reinforces intimacy. The exchange of saliva also introduces hormones like cortisol and adrenaline, potentially impacting the partner’s physiological state. Furthermore, mouth bacteria can even respond to neural messengers like oxytocin, dopamine, and endorphins, amplifying the feelings of pleasure during kissing.
Evolutionary Roots & Immune Benefits
Passionate kissing may also have evolutionary advantages. Sharing microbes could help partners build immunity to each other’s pathogens, offering a form of natural disease resistance. However, this exchange also carries the risk of spreading illness, which is why open-mouthed kissing is generally reserved for trusted partners.
What This Means for the Future
While these ideas are still hypothetical, Kort has proposed studies to test these theories. The next step may involve couples willingly undergoing detailed analysis of their saliva – and discovering just how intertwined their biology has become.
The science of kissing reveals a hidden layer of biological complexity beneath the surface of romance. Sharing saliva may be a far more powerful act than we’ve ever realized, linking affection, health, and even the very feelings of love through the invisible world of microbes.
