Food or Sex?

I have been discussing the varied and fascinating effects of the probiotic microorganism, Lactobacillus reuteri, specifically strains ATCC PTA 6475 and DSM 17938, that provoke release of the hormone, oxytocin, from the hypothalamus. Among the effects experienced by people who consume our L. reuteri yogurt is a dramatic reduction in appetite, the so-called anorexigenic effect, specifically interest in “hedonic” foods, i.e., indulgent foods like sweets, soft drinks, and French fries. In parallel with this, L. reuteri and the resultant rise in oxytocin also increase libido, i.e., interest in sex and procreation, as well as empathy and connectedness with your partner.

So we experience decreased interest in food and increased interest in our partner and others close to us with our L. reuteri yogurt.

Some have therefore speculated that oxytocin triggers an evolutionary pattern that helps ensure continuation of the species: It makes you more interested in sex in order to bear children, rather than devoting too much attention to procuring and consuming food. Once children enter the world, the maternal instinct and family connectedness are enhanced by oxytocin. It makes you more receptive to the touch of your partner, increases the pleasure of an embrace or kiss, cultivates deep connection with offspring. Obviously, there is a balance that needs to be struck between competing attentions of food and human relationships. But oxytocin is clearly a dominant factor that molds human behavior.

Here is a speculation: Given the dramatic reduction in prevalence of L. reuteri in modern people compared to people from just 60 or 70 years ago, and thereby a reduction in oxytocin, could this explain the dissolution of the family, the increase in divorce, the explosion of gun violence, i.e., the reduction in feelings of belonging, connectedness, and empathy for other people, that characterize modern life?

There may be other factors, other changes in the human microbiome that are influencing human behavior and health. But, as with so many things, looking back at how things used to be is revealing some astounding insights into what has happened to humans as a result of modern life. And, as our L. reuteri yogurt grows in popularity for its ability to reduce skin wrinkles, increase muscle, preserve bone density, deepen sleep, etc. will its social bond-increasing potential make this a happier, more connected, less vicious world?