You've Heard Probiotics, but How About Psychobiotics?

“All disease begins in the gut.”

-Hippocrates

Hippocrates, considered by many to be the father of medicine, was ahead of his time for having noted the importance of the health of the digestive tract over 2000 years ago. There is mounting evidence that what Hippocrates said is true, especially when it comes to the connection between our gut and our mental health.

What are psychoboitics?

These are probiotics with very specific benefits for our mental health. It is an emerging area in the field of psychology, but there are many studies showing that supplementation with these helpful organisms can affect our mood, our sleep and our emotions in a positive way.

How psychobiotics work?

It is believed that psychobiotics work by affecting our gut-brain-axis, a bi-directional system, made up of nerve pathways and hormone exchanges between the gastrointestinal tract and the autonomic nervous system (ANS). The ANS includes our brain and is related to functions that are automatic and we don’t consciously decide, things like our heart rate or digestion.

For some of us, worry or nervousness is felt like butterflies in our stomach and there is good reason for that. In a simple way we can think of psychological stress causing an inflammatory response in the gastrointestinal tract, along with other changes that for some people can lead to diarrhea and stomach pain. Because of this very close relationship between the nervous system and our hormones, sometimes the gut is referred to as the second brain.

One of the ways that psychobiotics can influence our mood, thoughts and mental abilities is through the production of chemical messengers and neurotransmitters such as dopamine and serotonin. They are both known as “feel good” chemicals produced by the brain, but actually 50% of dopamine and almost 90% of serotonin is synthesized in the gut.

Dopamine is responsible for that feeling of satisfaction that comes from having accomplished something, it activates the reward centers in our brain, but it can happen when someone likes our post, or when we eat a delicious meal. Serotonin is associated with feelings of happiness, focus and calm. It helps regulate stress, emotions, and sleep.

Where are psychobiotics found?

So how can we get some of these mood stabilizing bacteria’s into our gut? Fermented foods are natural sources of probiotics, kefir, kombucha, fermented veggies and more! The most common psychobiotics that have been studied up to this point are the lactobacillus and bifidus strains, these are often found in fermented dairy products such as yogurt.

In one study, healthy medical students were given either a daily probiotic drink or placebo for 8 weeks before exams. The placebo drink looked and tasted exactly like the probiotic drink but without the bacteria added. Cortisol was significantly higher in the placebo group compared to the probiotic group. Cortisol is a hormone that is often used to measure stress levels. The probiotic group also reduced gastrointestinal symptoms, such as decreased abdominal pain, indigestion and heartburn. Interestingly, the strain of bacteria used in this experiment is the same as the one found in Yakult, Lactobacillus casei Shirota. Yakult is a fermented milk product that originated in Japan, but is now ubiquitous in grocery stores across Asia.

How to keep psychobiotics active in our body?

Another thing to bear in mind is the importance of protecting helpful bacterial once it’s in our digestive tract. Fiber is an important source of fuel for all probiotics, psychobiotics included, so making sure that we consume a plant based diet is extremely important when it comes to maintaining a healthy gut. At the same time, we must consider the amount of pesticides in our food. Herbicides and pesticides are meant to kill pests, little bugs that can damage crops; however, our microbiome is also composed of little “critters” that are just as sensitive to these chemicals. If possible choose organic, but at the same time don´t avoid fruits or vegetables just because they aren’t pesticide free.

Please note that if you are taking medications for anxiety or depression or any other mental illness, this is not an invitation to stop taking them. It is, however, an invitation for all of us to consider incorporating more fermented foods into our diet. As the concept of psychobiotics is relatively new, there is still a lot of research that needs to be done. Various probiotic strains must be studied to determine which combinations and strains are best, as well as the ideal duration and frequency of treatment, but results are promising!

Just imagine, there are over 200 different lactobacillus species, each one with its own unique characteristics! The use of psychobiotics as a complementary therapy to conventional medical treatment is exciting, especially because of the inherent safety of probiotics, but we just aren’t there yet. In the meantime, enjoy fermented foods and try to learn how to make your own, the benefits might just blow your mind!

Reference and interest reading:

• Anxiety, Depression, and the Microbiome: A Role for Gut Peptides (https://pubmed.ncbi.nlm.nih.gov/29134359/)

• Classification of the glyphosate target enzyme (5-enolpyruvylshikimate-3-phosphate synthase) for assessing sensitivity of organisms to the herbicide (https://pubmed.ncbi.nlm.nih.gov/33243645/ )

• The effects of probiotics on depressive symptoms in humans: a systematic review (https://annals-general-psychiatry.biomedcentral.com/articles/10.1186/s12991-017-0138-2 )

• The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4367209/ )

• The Brain-Gut Axis: Psychological Functioning and Inflammatory Bowel Diseases (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7863941/)

• A Genome-Based Species Taxonomy of the Lactobacillus Genus Complex (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6722421/)

• Gut Microbiome Dysbiosis and Depression: a Comprehensive Review (https://pubmed.ncbi.nlm.nih.gov/32506238/)

• Fermented Milk Containing Lactobacillus casei Strain Shirota Preserves the Diversity of the Gut Microbiota and Relieves Abdominal Dysfunction in Healthy Medical Students Exposed to Academic Stress (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4959178/)

• Hidden Role of Gut Microbiome Dysbiosis in Schizophrenia: Antipsychotics or Psychobiotics as Therapeutics (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8307070/)

• Psychobiotics and the Manipulation of Bacteria–Gut–Brain Signals (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5102282/)

• Psychobiotics for Patients with Chronic Gastrointestinal Disorders Having Anxiety or Depression Symptoms (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8203266/)

• Role of the Intestinal Microbiome, Intestinal Barrier and Psychobiotics in Depression (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8000572/)

• Sleep and Microbiome in Psychiatric Disease (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468877/)