Brad King, MS, MFS
When you think about love and happiness, your gut probably isn’t the first thing that comes to mind. But what if I told you that a handful of tiny microbes living in your digestive tract could help brighten your mood, deepen your connections with others, and even make you feel more loving? Enter Lactobacillus reuteri and other gut-friendly bacteria. These “happy bugs” do more than digest food—they actively communicate with your brain through neurochemicals like serotonin, dopamine, and oxytocin[1].
Here’s the scoop on how they work, why they’re missing in many of us, and how you can bring them back into your life.
The Gut-Brain Connection: A Two-Way Street
Your gut and brain are constantly chatting through a complex network called the gut-brain axis. Think of it as a high-speed data cable running between your intestines and your brain. This communication relies on a few key neurotransmitters, otherwise known as brain chemicals[2]:
- Serotonin: Known as the "feel-good" molecule, about 90% of your body’s serotonin is produced in your gut.
- Dopamine: The reward center of your brain depends on dopamine, which influences motivation and pleasure.
- Oxytocin: Sometimes called the “love hormone,” oxytocin boosts feelings of trust and bonding.
Some probiotics, like L. reuteri, actively stimulate the production of these chemicals. Researchers have found that mice given L. reuteri became more social and less anxious—turning even the wallflowers into social butterflies[3]. Humans, too, can benefit from these effects, especially since these gut microbes influence mood-regulating pathways in the brain[4].
Missing Microbes: Why Your Microbiome Needs Help
Sadly, many of us are running low on these happiness-promoting microbes. Why? Blame it on the modern lifestyle:
- Antibiotics: While lifesaving (at times), antibiotics also wipe out beneficial gut bacteria alongside harmful ones. The worst part is, many of these—like L. reuteri, never come back!
- Highly Processed Diets: Low in fiber and prebiotics, these diets starve your gut microbes. You may not be able to break down fibers, but your happy bugs thrive on them!
- Chronic Stress: Chronic stress alters gut flora, reducing the diversity and abundance of good bacteria (yes, including the happy bugs)[5].
- Hygiene Hypothesis: Growing up in overly sanitized environments can limit exposure to diverse microbes (hand sanitizer anyone!?)[6].
Without these microbial allies, your gut struggles to produce enough of the happy, motivating brain chemicals; serotonin, dopamine, and oxytocin, which often leaves you feeling anxious, disconnected, or low energy[7].
Bringing Back the Bugs: How to Reintroduce Probiotics
Luckily, you don’t need a PhD in microbiology to nurture your gut. Adding specific probiotics to your diet is a straightforward solution. Here’s how:
- Probiotic Foods: Incorporate fermented foods like:
- Yogurt with live cultures (make your own, as store bought yogurt isn’t fermented long enough to create enough friendly microbes)[8]
- Kefir
- Sauerkraut
- Kimchi
- Miso
- Probiotic Supplements: Look for high-quality supplements containing L. reuteri. Be sure to choose strains backed by research. Dr. William Davis, the bestselling author of Wheat Belly and Super Gut (I’ve read both and highly recommend them), has a step-by-step guide on how you can make your own L. reuteri yogurt at the following link: https://drdavisinfinitehealth.com/2019/07/how-to-make-l-reuteri-yogurt-step-by-step/
- Prebiotic Foods: Probiotics need food, too. Prebiotics are fibers that fuel beneficial bacteria. Good sources include:
- Onions
- Garlic
- Bananas (non ripened)
- Asparagus
- Oats
- Research Proven and Targeted Prebiotics: Products like LeafSource® Real Bio-Gut (which is 100% certified organic and tastes great) provide the most research-proven prebiotics that cultivate an ideal environment for probiotics to thrive, ensuring your happy bugs stick around.
Caring for Your Gut Microbes
Probiotics are like houseplants: You can’t just bring them home and forget about them. Keeping your gut healthy requires consistent care:
- Eat the Rainbow: A diverse diet rich in whole, plant-based foods support a diverse microbiome[9].
- Reduce Sugar: High sugar intake feeds harmful bacteria and crowds out the good guys[10].
- Stay Hydrated: Water supports digestion and nutrient absorption[11].
- Manage Stress: Mindfulness practices, exercise, and good sleep habits can keep your gut-brain axis humming along[12].
The Science of Feeling Good
The benefits of probiotics are more than anecdotal. Research shows real connections between gut health and mental well-being:
- A 2016 study found that L. reuteri enhances oxytocin production and social behavior in animals, suggesting similar effects may occur in humans[13].
- A 2020 clinical trial demonstrated improved mood and reduced anxiety in participants taking L. reuteri supplements[14].
- Emerging studies are exploring how gut microbes impact conditions like depression and PTSD[15].
The evidence is piling up: a happier gut equates to a happier you.
The Bottom Line
Your microbiome isn’t just a digestive system—it’s a mood regulator, a social connector, and maybe even a love potion. By reintroducing probiotics like L. reuteri and supporting them with prebiotics and formulas like LeafSource® Real Bio-Gut, you can take control of your gut-brain connection.
After all, your gut’s happiness might just be the key to your own.
References
[1] Dooling, S. W., et al. (2022). The Effect of Limosilactobacillus reuteri on Social Behavior Is Independent of the Adaptive Immune System. mSystems, American Society for Microbiology.
[2] Lu, S., et al. (2024). The communication mechanism of the gut-brain axis and its effect on central nervous system diseases: A systematic review. Biomedicine & Pharmacotherapy, Elsevier.
[3] Xie, R., et al. (2020). Oral treatment with Lactobacillus reuteri attenuates depressive-like behaviors and serotonin metabolism alterations induced by chronic social defeat stress. Journal of Psychiatric Research, Elsevier.
[4] Wang, S., et al. (2020). Ingestion of Lactobacillus intestinalis and Lactobacillus reuteri causes depression- and anhedonia-like phenotypes in antibiotic-treated mice via the vagus nerve. Journal of Neuroinflammation, Springer.
[5] Gao, X., et al. (2018). Chronic stress promotes colitis by disturbing the gut microbiota and triggering immune system response. Proceedings of the National Academy of Sciences, National Academy of Sciences.
[6] Ege, M. J. (2017). The hygiene hypothesis in the age of the microbiome. Annals of the American Thoracic Society, American Thoracic Society.
[7] Stasi, C., Sadalla, S., & Milani, S. (2019). The relationship between the serotonin metabolism, gut-microbiota and the gut-brain axis. Current Drug Metabolism.
[8] Agustinah, W., Warjoto, R. E., & Canti, M. (2019). Yogurt making as a tool to understand the food fermentation process for nonscience participants. Journal of Microbiology & Biology Education, American Society for Microbiology.
[9] Maukonen, M., et al. (2024). Associations of plant-based foods, red and processed meat, and dairy with gut microbiome in Finnish adults. European Journal of Nutrition, Springer.
[10] Satokari, R. (2020). High intake of sugar and the balance between pro- and anti-inflammatory gut bacteria. Nutrients, MDPI.
[11] McQuilken, S. A. (2021). Digestion and absorption. Anaesthesia & Intensive Care Medicine, Elsevier.
[12] Christodoulou, et al. (2024). Mindfulness, Gut–Brain Axis, and Health-Related Quality of Life: The Paradigm of IBD Patients. Healthcare, MDPI.
[13] Buffington, S. A., et al. (2016). Microbial Reconstitution Reverses Maternal Diet-Induced Social and Synaptic Deficits in Offspring. Science, 351(6279), 819–824.
[14] Rao, A. V., & Bested, A. C. (2020). Role of gut microbiota in mood, behavior, and psychiatric disorders. Beneficial Microbes, 11(3), 221–232.