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Probiotics in Relieving Depression: How Gut Bacteria Play Its Role

Updated: Dec 8, 2023

Do You know the role of Probiotics in Relieving Depression?

In recent years, a growing body of research has delved into the intricate relationship between the gut and the brain. Interest in learning more about how gut bacteria may affect mental health has increased due to the two essential systems' bidirectional relationship. This article delves into the intriguing relationship between gut microbiota, probiotics, and their ability to reduce depression.

Scientists have identified through research that good bacteria improve the effectiveness of antidepressants and help relieve depression.

The experts use different types of medication and psychotherapy to relieve depression, but instead of a cure, depression persists in most cases. One of the most common and severe psychiatric disorders is Major Depressive Disorder (MDD).

However, there are currently no satisfactory treatments for it. Initial antidepressant treatment is ineffective for two-thirds of depressive patients, and even while receiving the best possible care, approximately 30% of treatment-resistant individuals still have symptoms.

Therefore, there is an urgent need to develop innovative, more effective treatment methods.

To invent new treatments for depression, research has been conducted that revealed the role of good bacteria probiotics in relieving depression, and in treating mental diseases, especially depression.

Here we will discuss how bacteria play a role in depressive symptoms and the relief of depression.

Understanding Depression

A common mental health condition called depression is characterized by enduring melancholy, despair, and disinterest in day-to-day activities. Medication and psychotherapy are common components of traditional therapies. On the other hand, recent studies indicate that the gut-brain axis may open up new therapeutic treatment options.

As an above-average prevalence of intestinal and digestive problems has been observed in patients with depression, scientists believe that the bacterial community may significantly influence depression symptoms in the gut.

The Role of the Gut Bacterial Community in Depressive Symptoms

The Brain-Gut Connection

The complex web of communication between the brain and the gastrointestinal system is known as the "gut-brain axis." An essential part of this axis, the vagus nerve, acts as a bridge to transfer impulses between these two systems. Knowing this link lays the groundwork for investigating the potential impact of alterations in the gut environment on mental health.

Role of Gut Bacteria in Mental Health

Gut microbiota has an essential role in mental health. There are an estimated amount of 1018 microorganisms that are present in the gut, and most of them are anaerobic bacteria. The gut microbiota performs various tasks related to nutrition absorption, food digestion, and bowel movements. It has been observed that the gut and the brain communicate in both directions, which can significantly impact stress, anxiety, and depression.

Probiotics in Relieving Depression: How Gut Bacteria Play Its Role

Pictorial representation of the link between gut microbes and depression  

As intestinal and digestive problems are more prevalent in patients with depression, researchers suspect intestinal flora’s influence on mental health.

According to research from the University of Basel and the University Psychiatric Clinics Basel (UPK). Health, particularly mental health, is significantly influenced by intestinal flora. Probiotics can enhance the effects of antidepressants and help in relieving depression.

What are Probiotics, and how are They Helpful in Relieving Depression?

Probiotics are those live bacteria that are helpful for us, especially for our digestive system.

They are generally called good or helpful bacteria because they help keep our gut healthy. There is a link between the gut and the brain, known as the gut-brain axis (GBA). The GBA axis links our nervous system and the gastrointestinal tract.

Research has been conducted involving 4 volunteers affected by depression problems. The study shows that Probiotics- Good Bacteria have a very positive response to treating mental illnesses and play an essential role in treating depression.

A research study was done at the University Psychiatric Clinics Basel (UPK), led by Dr André Schmidt and Professor Undine Lang. They investigated the effects of the probiotics on patients with depression. 

All individuals received antidepressants and either a probiotic (21 subjects) or a placebo (26 subjects) for 31 days while being treated as inpatients at the University Psychiatric Clinics Basel (UPK).

Probiotics supplements containing eight different strains, including (Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus Plantarum, Lactobacillus delbrueckii subsp. Bulgaricus, Lactobacillus paracasei, and Lactobacillus acidophilus) were subjected to the patients.

The researchers put the individuals through several tests before treatment, at the end of the 31 days, and then again four weeks later.

The analysis of the research revealed:

However, during the subsequent four weeks, the quantity of these gut bacteria that are good for our wellbeing declined once more. According to Anna-Chiara Schaub, one of the study’s lead authors, “it may be that four weeks of treatment is not long enough and that it takes longer for the new composition of the gut flora to establish.”

Modification in the Emotional Stimuli

Probiotics can also affect the brain’s emotional processing, which has been revealed while observing the neutral and fearful faces about the brain activity.

Using functional magnetic resonance imaging (fMRI), the researchers investigated brain activity. After four weeks, the brain activity was regular in the probiotic group but not in the placebo group.

Because Probiotics retained microbial diversity and enhanced the abundance of the Lactobacillus genus, showing their effectiveness in increasing specific taxa. In the probiotics group, there was a rise in Lactobacillus and a decrease in depression symptoms.

There is evidence that patients diagnosed with MDD and irritable bowel syndrome (IBS) experienced reduced depression symptoms after receiving Bacillus coagulans for 90 days.

In another research, a randomized controlled trial (RCT) showed improvement in patients with MDD’s self-reported depressive symptoms after an eight-week probiotic supplementation.

Factors That Affect the Gut Microbiota

There are several variables that affect the makeup of the gut microbiota, such as antibiotic consumption, lifestyle, and nutrition. Overall health depends on having a varied and well-balanced microbiome, and disturbances to this ecosystem have been related to mental health problems. A healthy gut environment may be achieved via eating a diet high in prebiotics, the food that beneficial gut bacteria eat.

Choosing the Appropriate Probiotic

Making the correct probiotic choice might have a significant positive impact on mental health. Individual reactions may differ, and various strains have distinct impacts. Getting advice from medical experts can assist in choosing the best probiotic for a person's unique requirements.

Prebiotics and Dietary Approaches

Prebiotics are just as important for maintaining a healthy gut flora as probiotics. These indigestible fibres, which are included in some foods, support a healthy gut environment by feeding beneficial bacteria. Prioritizing a range of nutrient-rich foods in one's diet will improve gut health in general and perhaps lessen depressive symptoms.

Cautions and Considerations

Even while probiotics may help manage depression, it's important to take these findings cautiously. To create precise recommendations for the use of probiotics as an adjunctive treatment for depression, more study is required. Before making major dietary or supplement changes, people should speak with healthcare providers.



It is concluded that probiotics have the potential for the therapy of depression and that good bacteria can relieve depression. According to other research, how they influence brain functioning and depressive behaviour has been observed. Studies revealed changes in gut microbiota composition in depressed patients and associations between gut microbiota and quality of life and depression. Some research shows that Probiotics are beneficial in lowering depression symptoms when given in combination with antidepressants but not when used as a stand-alone treatment.  

Thank you very much for reading the full article. If you are a research student and feeling any difficulty regarding research, feel free to visit the research playlist on the YouTube channel. We are pleased to have your attention. 

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