Tongue Kissing

Tongue Kissing – What You May Not Know

Intimate kissing involving full tongue contact and saliva exchange appears to be an adaptive courtship behavior unique to humankind and is common in over 90% of known cultures…

report researchers in Amsterdam.

So have you ever wondered what may be going on from a germ perspective during intimate kissing?

To answer this question, the researchers recruited 21 couples between the ages of 17 and 45 and asked them a number of questions about their frequency of kissing, most frequent kiss, most frequent meal, and meal composition. Then, the science began. The researchers sampled the front of the tongue of each participant before and after an intimate kiss and took samples of saliva as well.

The samples were processed to identify the types of bacteria present by analyzing the bacterial DNA.

Then, the researchers had one of the partners consume a probiotic yogurt drink. The tongue and saliva were sampled after 10 seconds and then the person was asked to kiss his or her partner for 10 seconds. At that point, the partner’s mouth was sampled specifically for the strains of bacteria in the yogurt drink.

The findings of the study were fascinating. As expected, those couples who kissed more frequently shared more similar mouth microbes. Even more intriguing was the finding that males strongly over-reported the number of times they thought they kissed their partner each day, by a factor of 2 to 1. But perhaps the most compelling finding, based on the probiotic yogurt part of the study, was that the calculated number of bacteria transferred from one partner to the next during a 10 second kiss was 80 million!

 So why do we do it? And it’s not just us. Mouth to mouth contact is seen across the animal kingdom from fish to birds to primates just like us. A scientific answer, at least according to the researchers in this study, explores how the first kiss, at least in human mating situations:

…serves as a useful mate-assessment function and the following for mediation of feelings of attachment in long term relationships, rather than the facilitation of sexual arousal. Kissing may contribute in mate assessment and bonding via sampling of chemical taste cues in the saliva, including those resulting from the metabolic activity of the bacterial community on the surface of the tongue.

Sounds like a lot of sciencespeak. But basically, it looks like intimate kissing plays a role not only in influencing how we select our mates, but also how we decide on long term relationships. And what’s really something to think about is the fact that once again, this is a great example of bacteria, in this case in the mouth, are directing our decision making process!

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  • Bill Stevens

    Men kiss in order to transfer testosterone,which increases sexual urges in their mate according to nature.

    • Mattv

      Maybe this would help explain why most lesbian bull dykes are overweight , maybe going down were they dont belong does something to gut bacteria,kills?

      • Violette

        Your remarks are a sign of ignorance and uncalled for, this is a site for people who appreciate and acknowledge an educated mind.

  • M Lebow, PhD

    An interesting question would be if individual gastrointestinal disorders improve when a person is in a relationship due to changes in the bacterial content. In contrast to social aspects or stress reduction due to the social connection.

    • Caryn Karason

      I have Ibs. I got worse after we got married ? not sure if it was because marriage comes with a complete change but my sensitive stomach suddenly turned into full blown Ibs.

      • Alex Papas

        If you have not already, look at the research into bacterial transplants and their results in lab studies.

      • Pia Curtis

        Maybe your diet changed to accommodate your partners preferences? ie eating more sugar, gluten, carbs etc or baking more foods that you know your partner fancies?

        Just a thought…..

        If not, onto the next item on the list to identify the cause.

    • Mark Dn

      I bet it doesn’t have much effect since the bacteria needs to get through the stomach acid but what do I know.

    • Alex Papas

      do people in successful relationships have healthy micro biomes ?

  • Stacey Marchione

    Love this. And so the bible Mark 10:8..”and the two will become one flesh.”

    • Mattv

      Thats awesome, beats the atheistic non scientific world view we evolved from apes that Perlmutter i think believes

  • Christine Wokowsky

    Great stuff as always doc! Love your posts. More microbial than human and counting.

    • David Perlmutter

      To paraphrase Michael Pollan, are we them, or are they us?

  • RicardoRichard

    If we continue to go deeper in this kind of research, perhaps we will learn one day that all human work, inventions and discoveries have been directed by bacteria, but which ones? Dr Perlmutter will discover perhaps that his last excellent two books require some important supplementary words in the acknowledgement – he should name the bacteria that helped him write his works… :-)))

  • Shawn Taylor

    If we need to drink our Mothers’ milk and eat a peck of dirt in our lives to satisfy the gut bacterial load that provides a good health profile, perhaps we also have to kiss a dozen mates to diversify the gut flora? It may be both our mouth cues and our gut flora that tells us when we’ve found a suitable mate.

    • Alex Papas

      kidding aside, yes you are on the money. Is that a bacterial mud mask you’re wearing?

  • Alex Papas

    Makes perfect sense to me. Does the philandering polygamist potentially have a strong case now. It’s not a psychological illness, sex addicts are literally sick. Is it possible that quitting refined sugars and consuming specific probiotics, fermented foods and the like might curb these urges? Just speculating.

  • John Brailsford

    I thought this started with mothers masticating food for their young offspring. The babies would get used to reaching for more food with their tongues pushed into their mother’s mouths.

  • Anne Ewan

    if gingivitis is (I read contagious)…. and many people unknowingly have it … then many people may be unwittingly transmitting this condition? If on the other hand the uninfected person is healthy hopefully their microbiome will protect them?