Can Probiotics Help Treat Depression and Anxiety?
There has been a great deal of interest in the human microbiome, which refers to the bacteria living within your body. Science has shown that we have close to ten times as many bacterial cells in our body as we do human cells.
Since the majority of these bacteria cells are known to live in your intestines, the beneficial role they play in keeping your digestive tract healthy has become increasingly well-known. What is not such common knowledge is that these friendly flora can benefit other parts of your body, too.
Specifically, there is a connection with the brain and mental health that has recently aroused great interest.
The Brain-Gut Axis
It has been recently theorized that changes in intestinal bacteria play a role in neurological conditions and mental health issues, such as depression and anxiety. Your intestines have their own nervous system, and this just happens to produce the same neurotransmitters as the brain (serotonin and acetylcholine).
These neurotransmitters play a key role in promoting gut motility, while too many or too few can cause irregular bowel movements and pain. With your gut and brain communicating via the same neurotransmitters, it is believed that the two organs can communicate with each other.
Because anxiety and depression involve irregularities with serotonin and acetylcholine, along with other neurotransmitters, it is thought that there may be a link between these disorders and abdominal irregularities. You can learn more about the healthy gut and brain connection in this article.
In other words, it is possible that anxiety and depression can trigger GI problems and complications and, in turn, conditions like chronic abdominal pain or constipation can lead to the development of anxiety and depression.
If this connection between gut and brain is real, then it might be possible for probiotics, which treat abdominal ailments, to also treat mental health conditions. With depression and anxiety affecting millions across the globe, a treatment as simple as a probiotic supplement would be a huge step forward.
A Whole New World: Psychobiotics
As strange as the name may sound, psychobiotics are a real thing in the world of science. These are live organisms (bacteria) that, when consumed in specific amounts, produce benefits for patients suffering from mental health issues and psychiatric illness.
As discussed, your intestines and your brain communicate using the same methods, so the actions of one can cause reactions in the other. Whether you are diagnosed with a chronic mental health disorder, like clinical depression or generalized anxiety disorder, or you just have low moods and anxiety-like symptoms, these psychobiotics can affect your brain and thus alter the impact of these diseases.
The ability for these bacteria to produce molecules like neurotransmitters means they do impact the brain and can alter function. With increased probiotic, or more specifically psychobiotic, intake, these bacteria cause certain reactions to be triggered within the gut wall, which causes the release of specific molecules that signal brain function and impact behavior.
They also have been thought to act on the brain through their anti-inflammatory activities. Chronic inflammation in your body is one of the key contributors to depression and other mood disorders.
Inflammation almost always stems from an unhealthy or unbalanced gut, so psychobiotics can reduce inflammation and, therefore, improve mood and behavior.
Finally, it is thought that these bacteria have an effect on your body’s stress response system, which involves your brain and adrenal glands.
Your stress response system is known as the HPA (hypothalamic-pituitary-adrenal) axis. This becomes dysfunctional when your body is under chronic stress or illness, and, as a result, the production of cortisol and other stress hormones is disrupted.
Because cortisol is produced according to a rhythmic timing, any disruption contributes to mood disorders and other cognitive problems.
The Contribution of Prebiotics
Prebiotics are essential in order to get the most from your probiotics. Given the close relationship between the two, it is understandable that prebiotics also regulate mood and brain function.
Studies have found that regular intake of prebiotics leads to a decreased amount of cortisol on the system and improved emotional processing. Participants in the study also showed increased positive attentional vigilance over negative, indicating that the prebiotics had anti-anxiety effects too.
People diagnosed with IBS (irritable bowel syndrome) also report depressive symptoms or are co-diagnosed with depression and/or anxiety. There is a direct correlation with dysbiosis and decreased gut microbial diversity (2) that supports the brain-gut connection and the theory that an unbalanced gut can impact brain function.
Psychobiotics and prebiotics can impact brain function, boost moods, help you to handle stress, and treat depression and anxiety. The best psychobiotics and prebiotics to use have yet to be determined, but a general daily dose of each (with at least 10 million CFUs) is likely to have a positive impact.
Treating Mental Health with Probiotics
Theoretically, bacteria play a role in chronic GI conditions, and these conditions can cause or trigger symptoms of anxiety and depression. This could mean that changing your intestinal bacteria situation by including probiotics in the mix might just help these chronic illnesses and the associated mental health problems.
Studies continue to refine our understanding of if this brain-gut connection can help discover a possible treatment option for neurological disorders. Details of the brain-gut connection are known, so it is only a matter of time before we define the direct link between gut bacteria and brain health.
At this point, there is no compelling data to support the idea of using probiotics to treat depression or anxiety, but the connection could lead to a beneficial outcome.
While probiotics should never replace the beneficial treatments for mental health issues, such as cognitive behavioral therapy or FDA-approved drugs, there still may be room for their beneficial contributions. There is evidence supporting the roles bacteria play in improving gut health, and, if the gut and brain are truly connected, the healing of one will inevitably lead to the healing of the other.