Gut Bacteria and Mental Health

Posted On: March 25, 2019
Categories:The Health Series,


By Ross Pelton, RPh, PhD, CCN

A major new study reports finding a relationship between gut bacteria, mental health and quality of life. The scientists discovered that people with depression had consistently low levels of certain strains of bacteria, regardless of whether they were taking antidepressants or not. The researchers also discovered several other strains of bacteria were much more commonly found in people who reported having a high level of mental health and quality of life.

The researchers reviewed medical records and microbiome fecal samples from over 1,000 people enrolled in the Flemish Gut Flora Project. While these findings and their relationship to mental health are very interesting, it is important to realize that association does not equal causation.

This study, which was published in Nature Microbiologyi, does not prove that gut microbes affect mental health. It is possible that the effect works the opposite way; a person’s mental health may promote the growth of strains of bacteria that like “living in a happy person.”

The profession of psychiatry is beginning to recognize that there is an important relationship between your gut microbiome and your mental health. In March 2014, a lead article in Psychology Today was titled: Nature’s Bounty: Psychobiotic Revolution.ii

Scientists are just beginning to learn how bacteria influence our mental and emotional health. However, studies like the one mentioned one reviewed in this blog post are providing fascinating insights.

i Valles-Colomer, et al. The neuroactive potential of the human gut microbiota in quality of life and depression. Nature Microbiology. Feb. 4, 2019.
ii Davidson J. Nature’s Bounty: Psychobiotic Revolution. Psychology Today, March 11, 2014.