Meet The Love Bug! Limosilactobacillus reuteri LR-99

“You’ve lost that lovin’ feelin’ …” sang The Righteous Brothers. Turns out it might have been found in the most unlikely place – our gut! So how does that work?

Did you know there’s an actual ‘love bug’?! A bacterium that could boost levels of the ‘love hormone’ oxytocin.

Oxytocin is a powerful neurotransmitter, and it causes that warm, fuzzy feeling we’re all familiar with. It forges a bond between mother and baby, sparks sexual chemistry between romantic lovers, and creates lasting ties between close friends.

So, fate and serendipity may play a role in our closest relationships, but science and some unlikely allies – our gut microbes – also play a part.

What’s the science behind it?

Our gut microbes – an estimated 100 trillion of them! – influence almost all aspects of our physical and mental well-being. In fact, they have a powerful effect on brain function and behavior.1

In one remarkable discovery, scientists found that a bacterium, with the long-winded name Limosilactobacillus reuteri, can improve social behaviour in mice.

Sean Dooling and his team (2022) studied mice with neurodevelopmental disorders and found their behaviour improved in a complex mechanism that involved both oxytocin and our vagus nerve. “Vagus” means wandering in Latin, an appropriate name for this long and complex nerve that connects our brain with our gut.

Not only that, L. reuteri could play a role in wound healing and immune function. In fact, our gut microbes are essential for immunity, and most immune cells are found in our gut, highlighting the importance of microbe-immune cell interactions.

So how can we make use of these discoveries?

Work is underway to develop potential treatments for a variety of conditions and to boost well-being in general. Specific microbial treatments draw considerable attention as investors are getting wise to this potential goldmine of new therapies.

Studies are needed in humans, but just imagine the power of a Love Bug – a probiotic bacterium that boosts our feel-good hormones!

This does not constitute or substitute for medical advice! Seek professional healthcare advice as needed, including which therapy or probiotic might be suitable specifically for you!

Further reading

1. The Effect of Limosilactobacillus reuteri on Social Behavior Is Independent of the Adaptive Immune System | mSystems (

2. The Effects of Limosilactobacillus reuteri LR-99 Supplementation on Body Mass Index, Social Communication, Fine Motor Function, and Gut Microbiome Composition in Individuals with Prader–Willi Syndrome: a Randomized Double-Blinded Placebo-Controlled Trial – PMC (

3. Oxytocin and the microbiome – ScienceDirect

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