Talk of probiotics and prebiotics seems to be everywhere. More and more people are realizing that these substances can help with gut health which, in turn, can improve overall health. But did you know that researchers are looking into prebiotics and probiotics for mental health too? Probiotics and prebiotics that can improve your mental health are known as psychobiotics. While psychobiotics is a new area of research, it’s exciting to think that foods and supplements could be used to treat mental illnesses like anxiety and depression, likely alongside traditional treatments like antidepressants. Learn more about psychobiotics and their possible uses below.
What Are Psychobiotics for Mental Health?
When looking at psychobiotics, the first thing to know about is probiotics. According to the Cleveland Clinic, probiotics are:
“a combination of live beneficial bacteria and/or yeasts that naturally live in your body . . . Probiotics are made up of good bacteria that helps keep your body healthy and working well.”
Psychobiotics are simply probiotics that are known to have an impact on one’s mental state, thanks to the way they alter gut health. Not all probiotics qualify as psychobiotics. Specifically, psychobiotics affect the central nervous system-related functions and behaviors through the way they change the microbiome, the community of microbes that inhabit your body.
For a microbe to be considered a probiotic, it must be able to:
• Be isolated from a human
• Survive in your intestine after ingestion (being eaten)
• Have a proven benefit to you
• Be safely consumed
The term “psychobiotics” also often refers to prebiotics alongside probiotics. According to the Cleveland Clinic, prebiotics are:
“complex carbohydrates that feed the microorganisms in your gut. Basically, prebiotics are the ‘food source’ for the good bacteria. They help feed the good bacteria and keep it healthy.”
Prebiotics, then, “feed” the probiotics in your microbiome.
Some definitions of psychobiotics also include something called postbiotics. Postbiotics are the products of bacteria, such as short-chain fatty acids.
Psychobiotics are currently an area of interest in research as they may aid in diagnosing and treating mental illnesses like anxiety and depression.
How Can Psychobiotics Be Used in Mental Health Diagnosis?
Psychobiotics are thought to affect our mental health by the way they affect our microbiome through something called the gut-brain axis. While you may not have considered that what you eat impacts what you think, it likely does. What you eat affects your gut which, in turn, affects a great amount of neural activity, including the production of neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (GABA), which are crucial for mental health. These neurotransmitters affect everything from mood to hunger, memory, and sleep.
No two person’s microbiomes are the same; in fact, they are even different in identical twins, but the better we understand the specifics of what the microbiome of a person with an illness, such as depression, looks like, the better we may be able to deal with that illness. Psychobiotics and their presence or absence may be able to help a person’s mental health through enhanced diagnosis, prediction of treatment response, and selection of treatment options.
For example, when it comes to diagnosing mental health issues, one day, a blood or stool sample may be all that’s needed. According to Medscape, in one small study, it was found that obese people with a depressive mood had altered levels of several amino acid derived metabolites (such as L-histidine and phenylacetylglutamine), which were linked to gut microbiota composition and function rather than to dietary amino acid intake. In other words, it appeared that the changes in the microbiome were due to mood state rather than the diets of the individuals. Similarly, a pilot study found that two bacteria (Prevotella and Ruminoccaceae genera) were candidates for distinguishing bipolar disorder and major depressive disorder. Greater study and understanding may mean that analyzing the microbiome of an individual can lead to a more accurate diagnosis of mental illness.
Psychobiotics May Also Show What Mental Health Treatment Will Work Best
Researchers are also interested in the possibility that studying the microbiome may offer clues as to which treatment will help a person, leading to something akin to personalized medicine. For example, one small study of those over 60 with major depressive disorder found that gut microbiota such as Faecalibacterium, Agathobacter, and Roseburia were associated with depression remission. A low differential of gut microbiota posttreatment was found in those whose depression didn’t remit. This means that analyzing gut microbiota may be able to indicate who will get better when given a particular treatment.
If researchers are right, and the presence of specific psychobiotics indicates who will respond to certain treatments, once a person’s microbiome is tested, a doctor should be able to select the most effective treatment for that person. This is vastly superior to today’s treatment methodology where some medications, antidepressants for example, may be plentiful, but choosing the one that will help any individual patient is almost a process of guess-and-check wherein the patient must try a medication for weeks to months, only to find out that it doesn’t work for them, forcing them to begin again with a new medication. Shortcutting this experience and being able to offer the treatment with the best chance of being effective first would be a huge boon for patients.
Mental Health Improvement with Psychobiotics
Psychobiotics are currently being tested in the treatment and even prevention of mood disorders like major depressive disorder and bipolar disorder, and things are looking promising. According to Medscape, in one meta-analysis of 50 randomized controlled trials involving psychobiotic interventions, a statistically significant benefit was found, whereas this was not found when inactivated parts of probiotics were used.
Additional reviews found that psychobiotics improved symptoms in those with major depressive disorder and in those with depression symptoms with additional diagnoses (like chronic fatigue syndrome), whereas those without these symptoms showed no effect on their mood. Psychobiotics have also been shown to reduce anxiety in those with depression. It’s worth noting that not only do psychobiotics seem to improve depression and anxiety perceptions but also their related behaviors.
How Do Psychobiotics Improve Mental Health?
It’s not known exactly how psychobiotics improve mental health, but some of their helpful effects may be due to their ability to decrease the stress response (the stress hormone cortisol), reducing inflammation.
According to an article in LiveScience:
“A 2021 review in the journal Progress in Neuro-psychopharmacology & Biological Psychiatry suggests that as the gut microbiome develops alongside the central nervous system, psychobiotics may be helpful in treating the effects of early life stress, which can cause developmental issues. This could help mitigate the impacts of childhood adversity and lead to a healthier adult life.”
It may also be that psychobiotics’ ability to reduce hypothalamic-pituitary-adrenal (HPA) axis activity (a negative and positive feedback system that regulates the physiological mechanisms of stress reactions, immunity, and fertility) may be helpful as this activity is associated with mental health conditions.
A link has been found between abnormalities in the intestinal barrier and depression. The article in LiveScience also states that through improving immune system responses, psychobiotics can restore proper immune functionality, and this leads to better overall intestinal barrier health.
Additionally, neurotransmitters related to mood are made in the gut. Deborah Lee, MD, states:
“A range of neurotransmitters are produced in the gut, including dopamine, serotonin, noradrenaline, acetylcholine and GABA.”
Popular antidepressants like vortioxetine (Trintellix), desvenlafaxine (Pristiq), and brexpiprazole (Rexulti) are also thought to work by modulating neurotransmitters in the brain.
What Types of Psychobiotics Are Best for Your Mental Health?
While psychobiotics are being actively researched to see how they can improve one’s mental health, it’s not yet clear the best way to create a more psychobiotic-rich microbiome. It may be that specific foods are the best way to improve one’s microbiome (see the following section).
That said, probiotic supplements are available on the market. Before investing in a supplement, however, it’s important to realize that supplements are not approved and regulated by the Food and Drug Administration (FDA) like pharmaceuticals are. According to the Cleveland Clinic, this means that,
“. . . manufacturers can sell supplements simply with ‘claims’ of safety and effectiveness.”
These claims may or may not be accurate.
Additionally, there is no guarantee that what is on the label is actually in the bottle as they don’t go through the kind of testing that pharmaceuticals do. (For example, it may not contain the amount of the probiotic it claims.) It is for these reasons that trusted brands of supplements are best.
Also, you should always talk to your healthcare provider before starting any kind of supplement to ensure it’s right for you. Remember, even over-the-counter supplements can interfere with other medications you may be taking, and they may or may not be right for you, particularly if you have a weakened immune system or you have recently had surgery.
Because research into psychobiotics is so new, it is difficult to say which psychobiotic is best to take.
For depression, the following psychobiotics and combinations may be useful and have been tested with positive results:
• Clostridium butyricum
• A combination of L. acidophilus, Lactobacillus casei, and Bifdobacterium bifdum
• A combination of L. casei, L. acidophilus, L. bulgaricus, L. rhamnosus, Bacillus breve, B. longum, and Streptococcus thermophiles and prebiotic fructooligosaccharides
• A combination of L. helveticus R0052 and B. longum R0175
If you’re buying a psychobiotic supplement, you may wish to ensure it includes some of the above.
It’s important to remember that psychobiotics alone are not recommended for a mental illness. A mental illness should always be treated by a mental health professional like a psychiatrist, with psychobiotics being used as an add-on, if appropriate.
What Foods Act Like Psychobiotics to Improve Your Mental Health?
A 2021 review in the journal of Modern Trends in Psychiatry indicates that if people with depression were to eat a varied, plant-based diet rich in fermented foods, it may improve their mental health due to the impact it would have on their gut microbiota.
While no particular food is known to act specifically as a psychobiotic, many foods are known to be good for your microbiome. These include fiber-rich foods like whole grains, berries, and cruciferous vegetables, along with fermented foods like:
• Yogurt
• Buttermilk
• Kefir
• Sourdough bread
• Cottage cheese
• Kombucha
• Tempeh
• Fermented pickles
• Fermented sauerkraut
• Kimchi
• Miso soup
It’s important for your diet to be varied as well. Too much of any one food prevents your body from repeating the benefits of the other food groups.
Whether you choose to take a supplement containing psychobiotics or eat a more varied, gut-friendly diet, you might just be doing your mental health a favor.
Sources
Dinan, T. G., Butler, M. I., & Cryan, J. F. (2021). Psychobiotics: Evolution of novel antidepressants. In Modern trends in psychiatry (pp. 134–143). https://doi.org/10.1159/000510424
Knapp, S. (2020). HPA Axis. Biology Dictionary. https://biologydictionary.net/hpa-axis/
Lackner, S. M. M. I. B. S. (2022, December 22). Advances in the gut microbiome and mood disorders. Medscape.https://www.medscape.com/s/viewarticle/985215
Mudge, L. (2022). What are psychobiotics? livescience.com. https://www.livescience.com/what-are-psychobiotics
Professional, C. C. M. (n.d.). Probiotics. Cleveland Clinic. https://my.clevelandclinic.org/health/articles/14598-probiotics
Sharma, R., Gupta, D., Mehrotra, R., & Mago, P. (2021). Psychobiotics: the Next-Generation probiotics for the brain. Current Microbiology, 78(2), 449–463. https://doi.org/10.1007/s00284-020-02289-5
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