I predict that the world will become a better place as more of us restore the microbe lost by nearly all modern people: Lactobacillus reuteri.

Recall that L reuteri is susceptible to common antibiotics such as ampicillin and amoxicillin. If you took one of these antibiotics for a bout of sinusitis or tracheobronchitis, you likely lost this important microbe from your gastrointestinal (GI) tract. With loss of L reuteri, you lost much of your ability to boost production and release of the hormone, oxytocin, from your hypothalamus. Recall that this microbe, via oxytocin, has effects such as smoothing skin wrinkles, encouraging deep sleep with vivid dreams, restoration of youthful muscle and strength, preservation of bone density, suppression of appetite, and advantages in pushing back SIBO (due to its upper GI-colonizing ability and capacity to produce bacteriocins effective against the species of SIBO, so potent that L reuteri is sometimes used to clean fermentation vats by probiotic manufacturers, all discussed in my book, Super Gut, including how to include this microbe as a factor in pushing back or preventing SIBO).

L reuteri colonizes the entire length of GI tract, from which it sends a signal via the myenteric nervous system lining the GI tract to the vagus nerve that, in turn, stimulates the hypothalamus to release oxytocin into the bloodstream. While experiences vary from individual to individual (likely due to genetic variation in the oxytocin receptor gene, of which there are at least five), most people experience a substantial increase in oxytocin (measurable in blood, saliva, cerebrospinal fluid) and all its marvelous effects. Note that the boost in oxytocin experienced with GI colonization of L reuteri is not brief and episodic, as it would be with hugging your partner or petting your dog, but continuous. Interestingly, the greatest boost in oxytocin occurs during sleep, especially following the first pass through REM sleep, suggesting that this phenomenon plays a role in favorably consolidating and re-orienting prior experiences, a factor in daytime mental health.

The boost in oxytocin has important social and emotional effects that include:

  • Increased empathy
  • Increased desire for social connection
  • Increased love and affection
  • Reduced social anxiety
  • Increased generosity
  • Increased ability to understand another person’s point of view

In other words, oxytocin shapes the human experience, influencing your thoughts and behaviors in ways that cultivate social interaction, fosters feelings of inclusion, intensifies bonds between people.

Better oxytocin status is not a utopia, however, as in selected situations the oxytocin boost can also encourage an us-versus-them mentality, as well as schadenfreude, gloating over someone else’s misfortunes. The dominant experience with increased oxytocin, however, is largely positive.

All in all, the thousands of people who are consuming the L reuteri yogurt that provides hundreds of billions of counts of the microbe are indeed reporting effects that include increased love and affection for their partner and family, less annoyance with coworkers, increased desire for human connection, reduced anxiety in social situations such as an office party or neighborhood get-together, and an enhanced ability to understand other people’s points of view, even if you continue to disagree.

Let’s face it: humans can be violent, bloodthirsty, self-serving creatures and have been for as long as our species has walked this planet. I am not proposing that, by restoring L reuteri, we will all live in a Mister Rogers’ utopian neighborhood. But if we could improve human social interaction even just a bit, well, I think that has to be a good thing.