This Is Your Brain On Psychobiotics: Can You Optimize Your Mood with Bacteria?

How are your serotonin and dopamine levels these days? Research carried out in the last few years leaves no room for doubt that bacterial imbalance in the gut not only causes gastrointestinal upset, it also leads to feelings of anxiety, difficulty concentrating, mood disturbance, and other emotional and cognitive effects.

We asked trusted gut health pro, Donna Gates of Body Ecology to explain the details so we can support our our well-being with smarter diet and supplements choices… 

What are psychobiotics?

You may have heard lately about the beneficial effects that certain fermented foods, like milk or coconut kefir, can have on the body, namely behavior and emotional state. Well, psychobiotics (like those in fermented foods) are beneficial bacteria (probiotics) or support for such bacteria (prebiotics) in the microbiome that produce neurotransmitters that have a direct influence on the gut-brain relationship.

“Scientists have found that most gut bacteria produce neurotransmitters (like dopamine and serotonin).”

So when all of those microbes that make up your gut microbiome are happy, you’re happy.Let’s look closely at the gut-brain axis and what we mean by psychobiotics.

What Happens in Vagus…

The vagus nerve is a direct line of communication between our gut and our brain. This nerve, a communication pathway, is bidirectional, meaning that whatever’s going on in our gut can influence our brain and whatever’s happening in our brain can affect our gut.

For most of us, this feels intuitive. We all know that not-so-great butterflies feeling when we’re nervous. And if you’ve ever experienced digestive upset for any reason, chances are it has also affected our mood.

So, how does this gut-brain connection work and, furthermore, how can we make it work to enhance health, including mental and emotional health?

There are a lot of ways that the beneficial bacteria (probiotics) in our gut can affect our mental and emotional state. The microbiota in our gut can, for instance, influence the connection of neurotransmitters, including gamma-aminobutyric acid (GABA), serotonin, catecholamines, and acetylcholine. These neurotransmitters have a direct effect on brain function, affecting our mood, how you think and feel, and even our behavior.(1)

Another way that probiotics affect the gut-brain axis is by inhibiting the overgrowth of pathogenic organisms in the gut. These pathogens can produce substances that have a negative effect on our mood, including proinflammatory molecules.(2, 3)

Lactobacilli and Bifidobacteria make up most of the bacteria in our gut, and these species can have a profound effect on inflammation and immune system activity, with secondary effects for brain function and mood. (4)

On the other hand, our mood and emotional state can affect our gastrointestinal system, again via the vagus nerve. Prolonged and severe stress can have a hugely detrimental effect on our gut health, creating something of a vicious cycle up and down our vagus nerve.

How can we use psychobiotics to break this cycle? Let’s look at some specific examples…

Psychobiotics in action

Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 are two of the best researched probiotics in the realm of psychobiotics. These bacteria support the body’s stress response system or hypothalamic-pituitary-adrenal (HPA) axis and can reduce levels of cortisol, the ‘stress hormone,’ which helps to relieve anxiety and can help lift our mood. (2)

L. helveticus R0052 and B. longum R0175 also reduce a variety of inflammatory markers and affect our levels of the neurotransmitters tryptophan and serotonin. It’s not surprising, then, that the combination of these probiotics has been associated with improvements in anxiety and nervousness, sleep quality, mood, and even symptoms of depression such as lack of enjoyment in normal activity. (5)

These two probiotics have also been associated with relief from abdominal pain, which may be partly related to their ability to significantly reduce levels of gut-derived lipopolysaccharides (LPS). (6) These molecules are critical in the development and progression of chronic low-grade inflammation and metabolic diseases.(7)
Many probiotics namely in fermented foods also help reinforce the intestinal barrier. And, with a healthier intestinal barrier, there’s less chance of pathogenic organisms entering the blood from a leaky gut.

Many gastric acid-resistant probiotics help to prevent pathogens from colonizing the gut.(8, 9) Our friend L. helveticus R0052, for instance, prevents Escherichia coli O157:H7 from sticking to cells in the intestine, and B. longum subsp. longum can also inhibit the ‘stickiness’ and activity of food-borne pathogenic bacteria.(10, 11)

Finally, lactic acid producing probiotics (found in fermented vegetables) increase levels of antioxidant enzymes including glutathione-S-transferase, glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase and catalase. (12) And with better antioxidant protection of brain tissue, the more likely you are to stay cognitively sharp and healthy as you age. Because the gut-brain axis might also affect brain inflammation, this has ramifications for healthy aging and cognitive acuteness later in life. (13, 14)

How to manage stress through diet…

Research carried out in the last few years leaves no room for doubt that bacterial imbalance in the gut not only causes gastrointestinal upset, it also leads to feelings of anxiety, difficulty concentrating, mood disturbance, and other emotional and cognitive effects. Optimizing our gut health by eating a diet rich in fermented foods, including milk kefir (made with an A2 milk and only if you do well on dairy), is increasingly seen as a sound way to support healthy brain function and a greater capacity for handling stress.

Note too, you cannot get the best of these probiotics anywhere except for in fermented foods.

For a lot of us, our usual stress management strategies may be off-limits right now, such as going to the gym, yoga class, or spending time in person with friends and family. And chances are that stress levels are higher than usual to boot! So, while it’s not a panacea, probiotic foods, milk and coconut kefir and fermented veggies—rich in the diversity that supplies many species of beneficial bacteria—are great tools to add to our stress-busting arsenal. Add them to your diet, if you haven’t already, since they help support those important neurotransmitters, immune function and all-round great health.

P.S. — If you’d like to add some psychobiotics to your diet, it turns out that this fermented beverage is not only delicious and ready for you on-the-go, it also has mood-boosting, stress-busting properties!

P.S.S. — If you know your gut is not balanced, I recommend that you don’t start out with all fermented foods right away, and instead try a non-dairy coconut kefir to help with repopulating your gut with good bacteria. Go slow with it. It’s also important to start rebuilding a healthy microbiome, which means you have to get rid of the problem first. That’s where this comes in – to target the bacterial layers where pesky pathogens are hiding.


1) Wall, R., Cryan, J.F., Ross RP, et al. (2014). Bacterial neuroactive compounds produced by psychobiotics. Adv Exp Med Biol, 817, 221-39. https://pubmed.ncbi.nlm.nih.gov/24997036/

2) Messaoudi, M., Violle, N., Bisson, JF., et al. (2011). Beneficial psychological effects of a probiotic formulation (Lactobacillus helveticus R0052 and Bifidobacterium longum R0175) in healthy human volunteers. Gut Microbes, 2(4), 256-261. https://pubmed.ncbi.nlm.nih.gov/21983070/

3) Jandu, N., Zeng, Z.J., Johnson-Henry, K.C., & Sherman, P.M. (2009). Probiotics prevent enterohaemorrhagic Escherichia coli O157:H7-mediated inhibition of interferon-gamma-induced tyrosine phosphorylation of STAT-1. Microbiology, Feb;155(Pt 2):531-40. https://pubmed.ncbi.nlm.nih.gov/19202101/

4) Bercik, P., & Collins, S.M. (2014). The effects of inflammation, infection and antibiotics on the microbiota-gut-brain axis. Adv Exp Med Biol, 817:279-89. https://pubmed.ncbi.nlm.nih.gov/24997039/

5) Wallace, C.J.K. (2017). The Efficacy, Safety, and Tolerability of Probiotics on the Mood and Cognition of Depressed Patients. 13th World Congress of Biological Psychiatry. Poster P-05-015, presented June 19, 2017. https://www.medscape.com/viewarticle/881877

6) Diop, L., Guillou, S., & Durand, H. (2008). Probiotic food supplement reduces stress-induced gastrointestinal symptoms in volunteers: a double-blind, placebo-controlled, randomized trial. Nutrition Research, 28(1), l-5. https://pubmed.ncbi.nlm.nih.gov/19083380/

7) Rodes, L., Khan, A., Paul, A., et al. (2013). Effect of probiotics Lactobacillus and Bifidobacterium on gut-derived lipopolysaccharides and inflammatory cytokines: an in vitro study using a human colonic microbiota model. J Microbiol Biotechnol, Apr;23(4):518-26. https://pubmed.ncbi.nlm.nih.gov/23568206/

8) Wine, E., Gareau, M.G., Johnson-Henry, K., & Sherman, P.M. (2009). Strain-specific probiotic (Lactobacillus helveticus) inhibition of Campylobacter jejuni invasion of human intestinal epithelial cells. FEMS Microbiol Lett. 2009 Nov;300(1):146-52. https://pubmed.ncbi.nlm.nih.gov/19765084/

9) Johnson-Henry, K.C., Hagen, K.E., Gordonpour, M., et al. (2007). Surface-layer protein extracts from Lactobacillus helveticus inhibit enterohaemorrhagic Escherichia coli O157:H7 adhesion to epithelial cells. Cell Microbiol, Feb;9(2):356-67. https://pubmed.ncbi.nlm.nih.gov/16925785/

10) Nishida, K., Sawada, D., Kuwano, Y., Tanaka, H., & Rokutan, K. (2019). Health Benefits of Lactobacillus gasseri CP2305 Tablets in Young Adults Exposed to Chronic Stress: A Randomized, Double-Blind, Placebo-Controlled Study. Nutrients, 11(8), 1859. https://doi.org/10.3390/nu11081859

11) Uraipan, S., & Hongpattarakere, T. (2015). Antagonistic Characteristics Against Food-borne Pathogenic Bacteria of Lactic Acid Bacteria and Bifidobacteria Isolated from Feces of Healthy Thai Infants. Jundishapur J Microbiol, Jun 1;8(6):e18264. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539568/

12) Kumar, M., Kumar, A., Nagpal, R., et al. (2010). Cancer-preventing attributes of probiotics: an update. Int J Food Sci Nutr, Aug;61(5):473-96. https://pubmed.ncbi.nlm.nih.gov/20187714/

13) Petra, A.I., Panagiotidou, S., Hatziagelaki, E., et al. (2015). Gut-Microbiota-Brain Axis and Its Effect on Neuropsychiatric Disorders With Suspected Immune Dysregulation. Clin Ther, May 1;37(5):984-95. https://pubmed.ncbi.nlm.nih.gov/26046241/

14) Bull, M. & Plummer, N. (2014). Part 1: The human gut microbiome in health and disease. Integrative Medicine, 13(6), 17-22. https://pubmed.ncbi.nlm.nih.gov/26770121/

The Chalkboard Mag and its materials are not intended to treat, diagnose, cure or prevent any disease. All material on The Chalkboard Mag is provided for educational purposes only. Always seek the advice of your physician or another qualified healthcare provider for any questions you have regarding a medical condition, and before undertaking any diet, exercise or other health-related programs.

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