Psychobiotics supplements: What are they? How do they work?

Researchers are still understanding all the ways that gut bacteria can influence your mind, here are some ways by which gut bacteria and probiotics do so.

What are psychobiotic supplements?

Psychobiotics are probiotics and prebiotics that can deliver mental health and cognitive benefits through the gut-brain axis. Researchers are still understanding all the ways that gut bacteria can influence your mind, here are some ways by which gut bacteria and probiotics do so:

  • Producing neurotransmitters – neurotransmitters in the gut may not directly increase neurotransmitters in your brain, but they can work through your gut neurons to influence your brain functions.
  • Producing other brain-influencing substances, such as short-chain fatty acids and neurotransmitter metabolites.
  • Communicating with your brain through the vagus nerve.
  • Balancing inflammation and oxidative stress levels in your entire body. Inflammation and oxidative stress can interfere with your brain function, causing sluggish brain and bad mood.

Many herbs also work with gut flora to activate certain substances, or work by improving the gut flora, such as the Chaihu Shugan San formula in our Cognibiotics.

Keep in mind most of these psychobiotic studies are in rodents. In most cases, to reap the same benefits, you’d need to pick probiotic formulations that are optimized to survive your digestion rather than ones that just have these strains.

Dosages should be in the billions to ten billions. However, spore-based bacteria or some preparations are made to survive digestive conditions and deliver benefits at a lower dose.

The results also likely vary from person to person, as a meta-analysis of clinical trials for mood-enhancing effects of probiotics showed significant but likely heterogeneous.

This is why we formulated Cognibiotics with the most powerful psychobiotic strains and cognitive-enhancing Chinese herbs that synergize with probiotics.

How do probiotics for mental health work?

Supporting Healthy Stress Response (HPA Axis)

In rodents, supplementation with these strains reduced cortisol and mitigated some stress-related symptoms:

  • L. plantarum
  • L. helveticus
  • L. fermentum
  • L. rhamnosus
  • L. casei

B. longum 1714 – A randomized, double-blinded placebo-controlled trial tested 40 subjects on B. longum 1714 vs placebo for 4 weeks. All subjects played the Cyberball game to simulate social stress.

Magnetoencephalography (a magnet non-invasive brainwave measurement) found that the probiotic group had increased theta brain wave in the frontal and cingulate cortex, and lower beta brainwave in the hippocampus, fusiform, and temporal cortex.

These changes are associated with subjective vitality and reduced mental fatigue.

In another clinical trial, 22 subjects completed cognitive assessments with EEG brainwave measurements after a cold pressor test, either after taking 109 (1 billion) CFU B. longum 1417 or a placebo.

The probiotic groups had less cortisol increase and subjective situational anxiety response along with reduced stress and improved memory.

L. plantarum PS128 reduced inflammation and corticosterone levels, while increasing dopamine, thus reducing traits resembling mood issues in mice.

Improving Neurotransmitter Balance

  • L. plantarum, L. helveticus, L. fermentum, L. rhamnosus, and B. infantis change animal behaviors partly by influencing levels of neurotransmitters serotonin, dopamine, and GABA in the brain. These good bacteria also crowd out the bad bacteria and reduce the enzymes that may convert healthy neurotransmitters into neurotoxic metabolites.
  • Bifidobacterium breve CCFM1025 upregulates tryptophan, 5-HTP, and serotonin in the gut.

Producing Neurotransmitters in the Gut

Many probiotics produce neurotransmitters. However, neurotransmitters and similar molecules in the gut may not increase neurotransmitters in the brain.

Most neurotransmitters are too large to cross the blood-brain barrier, therefore neurotransmitters in the brain are produced and maintained separately from those in the gut.

While taking GABA orally doesn’t increase brain GABA, most people will find relaxation effects. Oral GABA helps you feel relaxed through GABA receptors in your gut, and presumably, GABA produced by your gut bacteria works similarly

Here, we’re only including probiotic strains that are generally recognized as safe and available in dietary supplements. Neurotransmitter production is based on high-performance liquid chromatography detection.

Bifidobacterium longum BL21
Lactobacillus plantarum CW006
Lactobacillus plantarum N13
Pediococcus acidilactici
Lactobacillus pantarum Lp90
Lactobacillus brevis LB01
Lactobacillus paracasei LC86
Lactobacillus helveticus LH76
Lactobacillus casei LC89
Lactobacillus jensenii LJe52
Lactobacillus rhamnosus LRa05
Lactobacillus gasseri LG08
Lactobacillus acidophilus LA85
Lactobacillus reuteri LR08
Lactobacillus salivarius
Lactobacillus bulgaricus
Lactococcus lactis subsp lactis
Bifidobacterium lactis
Bifidobacterium breve
Streptococcus thermophiles
Lactobacillus fermentum
Bifidobacterium bifidum
Bifidobacterium infantis
Leaky Gut Guardian (vanilla flavor)
Leaky Gut Guardian (chocolate flavor)

Supporting Neurogenesis and Neuroplasticity With Prebiotics

Prebiotic fermentation by good bacteria produces short-chain fatty acids that can induce brain fertilizer proteins, such as BDNF. These can have potent cognitive, mood-enhancing, and anti-aging benefits for your brain.

In rats, gavaging (force-feeding) with prebiotics called fructooligosaccharides (FOS) and galactooligosaccharides (GOS), GOS increased markers of neuroplasticity and glutamate signaling in the hippocampus.

When the researchers applied the plasma of rats that had GOS to human nerve cells, the nerve cells produced more BDNF.

Protecting the Brain Against Oxidative Stress

L. acidophilus, B. lactis, and L. fermentum increase antioxidant enzymes and improve cognitive function in rats with elevated oxidative stress.

Our internal lab tests detected some antioxidant activities with P3-OM and probiotic strains in Cognibiotics.

Stimulating the Vagus Nerve

There have been multiple rodent studies that observe neurochemical changes in the brain after the animals eat probiotics. Cutting the vagus nerve effectively prevents these neurochemical changes from occurring.

Lactobacillus rhamnosus JB1 is one such bacteria strain that significantly stimulates the vagus nerve.


Your gut flora can play powerful roles in your mindset, mental health, and cognitive functions so it’s important to feed them right. Also, consider adding research-backed psychobiotics like Cognibiotics to your mood and cognitive enhancement toolbox.


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