New horizons in the fight against depression? Scientific studies reveal a link between probiotics and mental health

Depression has become one of the most common diseases worldwide and a leading cause of disability. It is estimated that several percent of adults experience it at some point in their lives. This lifestyle-related disorder affects people regardless of age, gender, lifestyle, or social status. Individuals between 25 and 55 years of age are particularly vulnerable, although it increasingly affects both seniors and adolescents.

The growing number of depression cases makes it a serious global social and public health issue. The alarming rate of increase has prompted researchers to investigate the topic and search for new, effective methods to combat this disease. What can we learn from the research?

Significant Improvement in Mood

More than 100 years ago (in 1909), Dr. Hubert Norman used sour milk in the treatment of melancholy, and in 1910, Dr. George Porter Phillips published an article on treating it with lactic acid bacteria. Despite these early findings, awareness of the link between gut health and emotional well-being remained low for many decades.

Only in the last decade have numerous randomized, double-blind, placebo-controlled clinical trials demonstrated the effectiveness of probiotics in preventing and treating depressive and anxiety disorders. These studies—including two major meta-analyses (Huang, R.; Wang, K.; Hu, J. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Ng QX, Peters C, Ho CYX, Lim DY, Yeo WS. A meta-analysis of the use of probiotics to alleviate depressive symptoms)—confirmed that psychobiotic supplementation significantly improves mood in both healthy individuals and patients with depression.

Importantly, the use of probiotic supplements was not associated with serious side effects—adverse reactions were rare and mild in nature.

Psychobiotics — Probiotics Beneficial for Mental Health

The term “psychobiotics” refers to probiotic bacteria that, when consumed in appropriate amounts, support mental health. They play a key role in promoting the production of neurotransmitters responsible for mood regulation. For instance, they help convert tryptophan into serotonin—a hormone that regulates mood, sleep, and libido.

Probiotics and prebiotics also strengthen the intestinal barrier, preventing “leaky gut syndrome.” This reduces the passage of toxins and pathogens into the bloodstream, which can trigger inflammation. Reducing inflammation in the body, especially in the brain, has a direct impact on mental well-being.

Recent studies show that a diet rich in probiotics and prebiotics can significantly improve mood, reduce symptoms of depression and anxiety, and support overall mental health. Regular consumption of fermented foods such as yogurt, kefir, and pickled vegetables, along with targeted probiotic supplementation, may be an effective way to support the gut-brain axis and improve emotional balance.

How Do You Know if a Probiotic Is Effective?

Choosing the right psychobiotic is crucial. Unfortunately, the market offers a wide range of products whose effectiveness has not been confirmed. If you decide to supplement with probiotics, pay close attention to the key aspects listed below.

First, check whether the species, strain, and type of bacteria are clearly stated on the label, e.g., Lactobacillus acidophilus Er-2 strain 317/402 Narine. Also note the number of colony-forming units (CFU) per capsule, which should remain stable until the expiration date—this reflects the product’s viability and efficacy.

Probiotics come in capsules with either a standard coating (which dissolves in the stomach) or enteric coatings, which protect bacteria from stomach acid, digestive enzymes, and bile salts. These products are labeled as “enteric” or “gastro-resistant.” Preventing breakdown in the acidic stomach environment allows the bacteria to reach deeper parts of the digestive tract, where they can function effectively.

Narum Relax — Natural Support for Mind and Body

Narum Relax combines probiotics with calming plant extracts. Thanks to carefully selected strains of probiotic bacteria and relaxing ingredients such as lemon balm leaf extract and hop cone extract, Narum Relax helps maintain a balanced gut microbiota, positively influencing both body and mind. This product is designed to naturally support mental health.

The Narine strain (Lactobacillus acidophilus) provides ideal support for those seeking natural ways to boost emotional well-being and resilience to stress—each capsule contains 5 × 10⁷ CFU of bacteria. You can learn more about this product at Narum Relax 200 mg.

A mindful approach to mental health can greatly improve quality of life—take care of yourself and your loved ones.

Important Note

Although the results of studies on the effects of probiotics on mental health are promising, no product should be used as a sole treatment. Depressive and anxiety disorders require consultation with a psychiatrist or licensed psychologist.

If you have been struggling with emotional difficulties for some time and feel your mental health is deteriorating, seek professional help first. Only a qualified specialist can properly assess your situation, make a diagnosis, and recommend the right treatment.

Helplines in Poland:

• Helpline for adults: 116 123 (available daily 2:00 p.m. – 10:00 p.m., free of charge)

• Helpline for children and adolescents: 116 111 (available daily 12:00 p.m. – 2:00 a.m., free of charge)

• Support Center for People in Mental Crisis: 800 70 2222 (available 24/7, free of charge)

• Polish Psychological Association: www.ptp.org.pl