Psychobiotics: Connecting The Gut Microbiome and Brain

Written by Angie Arriesgado
featured image for article on psychobiotics

Probiotics, like our Intelligent Labs Probiotics supplements, have been selling like hotcakes in recent years. These live microorganisms may be invisible to the naked eye, but you can feel their benefits throughout your whole body. That’s right – probiotic benefits aren’t limited to the digestive system; they also extend to the brain! In this blog post, we’ll introduce psychobiotics and how they connect the brain and gut together.

What are psychobiotics?

Psychobiotics are a class of probiotics that may provide mental health benefits. Psychobiotics produce neurotransmitters that nerve cells, a.k.a. neurons, use to “talk” to each other. In particular, serotonin, dopamine, GABA, norepinephrine, and acetylcholine are examples of neurotransmitters produced in the gut (1).

Currently, several bacterial strains have been identified as psychobiotics, including (2, 3):

  • Lactobacillus rhamnosus
  • Bifidobacterium breve
  • Lactobacillus casei
  • Bifidobacterium longum
  • Lactobacillus paracasei
  • Lactobacillus plantarum

All six psychobiotic strains are found in our Adult Probiotics and Prebiotics. Each capsule contains 10 patented acid and bile resistant strains as well as 2 types of prebiotic fibers to nourish the probiotics. We also use active packaging technology and delayed-release capsules to help ensure the probiotics reach your gut alive!

What is the gut microbiome and how does it affect your health?

The gut microbiome is home to trillions of microorganisms, such as bacteria, fungi, and viruses. As you can probably tell, psychobiotics belong to the “good” kind of bacteria.

The gut microbiome is absolutely essential to our existence. These microbes help digest food, boost our immune system, and even maintain our mental health (4)!

But this living ecosystem needs a balance between its good and bad “residents”. The alternative is undesirable, to say the least. Most of us have wrestled with the effects of gut imbalance at one time or another. Well-known symptoms range from mild digestive discomfort to severe intestinal infections.

How can microbes in the gut possibly affect mental health?

The gut microbiome influences how you think, behave, and react to stress (5). But how? Well, there’s this thing called the gut-brain axis.

As the name suggests, this axis connects the gastrointestinal tract with the brain and central nervous system. This axis is the reason why the state or composition of your gut microbiota may directly affect your mental state! For example, if you’re feeling anxious, depressed, or having problems concentrating, it may be due to gut dysbiosis (6).

In addition to the “butterfly in the stomach” feeling, the gut-brain axis is also said to be responsible for our so-called “gut instincts”. It’s that unexplainable feeling where we’re absolutely sure about something but can’t explain why.  

Interestingly, scientists have also discovered that most people with autism have some type of abnormality in the gut. These may be in the form of allergies, gluten sensitivity, digestive issues, etc. The culprit? A lower number of Bacteroides fragilis species in the gut (7).

To determine if increasing the population of B. fragilis can help improve symptoms, the researchers fed mice (with autism symptoms) with this particular strain. Surprisingly, it worked! The mice’s gut microbiome changed, and more importantly, improved their behaviour, too (7).

And here’s the kicker – these microbes may even play a role in how our personalities develop. To test this theory, scientists used germ-free mice and transplanted bacteria from donor mice. Amazingly, the previously-germ-free mice took on the personality of the donor mouse (8)!

How does the “second brain” fall into all this?

Wait, what? There’s a second brain?

We obviously only have one organ called “brain”. But for all intents and purposes, the Enteric Nervous System (ENS) actually also fits the bill. Enteric means “intestinal,” so the ENS literally translates to “intestinal nervous system”.

The ENS is embedded in the lining of the gut, stretching from the oesophagus all the way to the rectum. It has a mesh-like system of hundreds of millions of neurons (9). It might sound like a lot, but it’s tiny compared to the big brain’s 86 billion neurons!

The ENS may not be capable of thought just like the brain, but it is capable of functioning independently of the central nervous system (the brain and spinal cord). As a result, the gut can automatically process, digest, and absorb our food without us needing to think about it.

What are the mental health benefits of psychobiotics?

The field of psychobiotics is relatively young, but the mental health benefits seen in (mostly) animal studies are very promising. Here are some of them:

Psychobiotics may help improve psychiatric disorder-related behaviours

Researchers analysed 38 randomised controlled trials that studied various probiotic strains’ effects on humans and animals (2). They found that probiotics helped improve behaviours, such as:

  • Anxiety
  • Depression
  • Autism spectrum disorder
  • Obsessive-compulsive disorder
  • Memory

The majority of the studies used Lactobacillus and Bifidobacterium strains, including some of the strains found in our Adult Probiotics and Prebiotics supplement!

Psychobiotics may help boost neurotransmitter production

Different neurotransmitters do different things, but they all have an effect on the body. For instance, serotonin is known as a mood stabilizer, while dopamine is known as a reward chemical. Up to 90% of serotonin and 50% of dopamine are produced in the gut (10, 11)!

As mentioned earlier, most of these neurotransmitter-producing strains are found in our Intelligent Labs Adult Probiotics & Prebiotics.

Psychobiotics may help improve mood and reduce depression

Scientists did a systematic review of five clinical trials that involved over 180 subjects and controls. They concluded that probiotics have a positive effect on major depression symptoms, especially in patients 60 years old and below. Apparently, however, they did not have the same effect on patients 65 and above (12).

So, what could be a good alternative for older folks then?

Well, psychobiotics aren’t the only thing that can help improve mood and relieve anxiety. Natural nootropics like our Seneca Nootropic Complex, Lion’s Mane Mushroom Extract, and Phosphatidylserine may also help! Research has shown that nootropics can also help improve mood, mental drive, and motivation.

Now, whether you intend to take psychobiotics or nootropics for their mental health benefits, we highly recommend you seek professional medical advice first.  


A healthy gut microbiome is vital for brain and mental health. As you’ve learned in this blog post, they also help improve mood and alleviate depression and anxiety.  More research is needed on humans for sure, but the studies done so far have been very promising indeed!


(1) Wall, Rebecca, et al. “Bacterial Neuroactive Compounds Produced by Psychobiotics.” SpringerLink, 2014,

(2) Wang, Huiying et al. “Effect of Probiotics on Central Nervous System Functions in Animals and Humans: A Systematic Review.” Journal of neurogastroenterology and motility vol. 22,4 (2016): 589-605. doi:10.5056/jnm16018

(3) Yong, Shin Jie et al. “Antidepressive Mechanisms of Probiotics and Their Therapeutic Potential.” Frontiers in neuroscience vol. 13 1361. 14 Jan. 2020, doi:10.3389/fnins.2019.01361

(4) Bull, Matthew J, and Nigel T Plummer. “Part 1: The Human Gut Microbiome in Health and Disease.” Integrative medicine (Encinitas, Calif.) vol. 13,6 (2014): 17-22.

(5) Foster, Jane A. “Gut feelings: bacteria and the brain.” Cerebrum : the Dana forum on brain science vol. 2013 9. 1 Jul. 2013

(6) Clapp, Megan et al. “Gut microbiota’s effect on mental health: The gut-brain axis.” Clinics and practice vol. 7,4 987. 15 Sep. 2017, doi:10.4081/cp.2017.987

(7) Hsiao, Elaine Y et al. “Microbiota modulate behavioral and physiological abnormalities associated with neurodevelopmental disorders.” Cell vol. 155,7 (2013): 1451-63. doi:10.1016/j.cell.2013.11.024

(8) Schmidt, Charles. “Mental Health May Depend on Creatures in the Gut.” Scientific American, 1 Mar. 2015,

(9) Fleming, Mark A 2nd et al. “The Enteric Nervous System and Its Emerging Role as a Therapeutic Target.” Gastroenterology research and practice vol. 2020 8024171. 8 Sep. 2020, doi:10.1155/2020/8024171

(10) Yano, Jessica M et al. “Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis.” Cell vol. 161,2 (2015): 264-76. doi:10.1016/j.cell.2015.02.047

(11) Eisenhofer, Graeme, et al. “Substantial Production of Dopamine in the Human Gastrointestinal Tract.” The Journal of
Clinical Endocrinology & Metabolism, vol. 82, no. 11, 1997, pp. 3864–71. Crossref,

(12) Huang, Ruixue et al. “Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” Nutrients vol. 8,8 483. 6 Aug. 2016, doi:10.3390/nu8080483