Anxious or depressed all the time? But you don’t want to take risky medications? How about considering probiotics for your health? Probiotics are beneficial bacteria that play a crucial role in maintaining gut health and overall well-being. And they certainly can do work for healthy mental conditions.

Mental health issues
Like depression, anxiety, and brain fog. Suprise? Scientific discoveries demonstrated that these living microbial consortiums may impact anxiety, depression, cognitive functions, stress responses and behaviours (1). Probiotics can influence mental health through several mechanisms due to the close connection between the gut and the brain, known as the gut-brain axis. This network is not only anatomical, but it extends to include endocrine, humoral, metabolic, and immune routes of communication as well (3). The gut is always ready to influence mood, cognition, and mental health. The gut-brain axis communication literaly indicates the nervous system between the gut and brain, and the immune system is also involed. Probiotics can modulate these communication pathways, influencing brain function and behavior.

Some probiotics actually makes neurotransmitters like serotonin, dopamine, and gamma-aminobutyrid acid, also called GABA. Subtypes of Lactobacillus and Bifidobacterium are those family which can make neurotransmitters. Those probiotics that controls the functioning or actions of central nervous system (CNS) conciliated by the gut brain axis (GBA) through neural, humoral and metabolic pathways to ease the gastrointestinal activity as well as anti-depressant and anxiolytic capacity are known as psychobiotics (2).
Among probiotic-produced neurotransmitters, serotonin might be the most effective chemical that makes the brain feel good. A large amount of serotonin is produced in the gut. When it reaches the brain and nerve system, it regulates mood, appetite, and sleep.
Probiotics can influence the hypothalamic-pituitary-adrenal (HPA) axis, which controls the body’s response to stress. By modulating the HPA axis, probiotics can help reduce the physiological impact of stress. HPA axis controls the body’s response to stress, so modulating this pathway is crucial.
Animal and human studies have shown that probiotics can improve behaviors and cognitive functions. For example, probiotics have been found to reduce anxiety-like behavior and improve cognitive performance in various studies. Stress often negatively impacts cognitive functions such as memory and concentration. Probiotics may improve cognitive function by reducing inflammation and oxidative stress in the brain.
The studies of probiotics in major depressive disorder is somewhat new field of science. But it is extremely noteworthy to dig in. Production of relaxing neurotranmitter and HPA axis are significantly involved with the microbiome in the gut. Probiotics, both as an adjunct to antidepressants or a stand-alone intervention, have a beneficial role and potential in mitigating anti-depressive effects, and confers some advantages compared to conventional treatments of depression using anti-depressants (2).

Physiological effects
Probiotics help our body through many other mechanisms. First, they suppress inflammation, especially chronic inflammation, which is linked to depression and other mental health disorders. Probiotics can help reduce inflammation by balancing the gut microbiota and enhancing the gut barrier function, preventing inflammatory compounds from entering the bloodstream.
These chronic symptoms can also be regulated through a well-functioning immune system. The gut microbiota plays a crucial role in the immune system. An imbalance in gut bacteria can lead to immune system dysregulation, associated with various mental health conditions. Probiotics help maintain a balanced immune response.
A healthy gut lining also prevents harmful substances from entering the bloodstream. Probiotics can strengthen the gut barrier, reducing the risk of systemic inflammation and its negative impact on mental health. Gut bacteria makes short-chain fatty acids (SCFAs). SCFAs have anti-inflammatory properties and can affect brain health and function.

Conclusion
Probiotics have been studied for many decades and exponentially expanded through therapeutic research. As we discussed, probiotics-mediated microbiota modulation within the microbiota–gut–brain axis is a crucial key to relieving mental and physiological stresses.

References
(1) Approach of probiotics in mental health as a psychobiotics. Archives of Microbiology, 2022
(2) Nutrients 2021, 13(5), 1728
(3) The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integr Med (Encinitas). 2018 Aug; 17(4): 28–32.