Mental health and gut health

Nowadays, there is no doubt that the human gastrointestinal microbiota plays a fundamental and crucial role in the functioning of our brain, and almost all disorders that occur in it have a direct impact on our mental health. In recent years, the gut-brain axis has gained an important position in explaining a wide range of human behavior, emotions or even some disease entities, and yet, social awareness in this aspect is still at an unsatisfactory level.

It has been shown, that people suffering from various mental disorders (including depression, bipolar disorders, schizophrenia and autism) have significant differences in the bacteria that make up their intestinal microbiota and the strengthening of beneficial bacteria in the intestines, for example by using appropriate probiotics, prebiotics and diet have great potential for improving the symptoms presented by sick people. In addition, the procedures mentioned above can also significantly increase the quality of life in people who have not been diagnosed with any psychiatric disease and are struggling with malaise or frequent anxiety every day.


While comparing the intestinal microbiota of people suffering from depression with the microbiota of healthy people, significant differences were noted in its composition. A group of researchers in Belgium conducted a large-scale study in which they found a link between microbiome quality and quality of life along with symptoms that occur in depression. They found that two types of bacteria (​Coprococcus and ​Dialister​) were scarcely found in people suffering from depression (regardless of the antidepressant used), while higher levels of ​Faecalibacterium and ​Coprococcus producing butyrate were associated with better quality of life. In addition, the latest meta-analyzes in most cases confirm the positive effect of probiotics on mood.

Bipolar disorder

Two new clinical studies have shown the beneficial effects of probiotics on the mental state of people suffering from bipolar disorder. The first observed an improvement in cognitive functions in 20 people after 3 months of consuming probiotics containing 9 different strains of ​Lactobacillus and ​Bifidobacterium​. In the second, randomized trial of 66 patients, probiotics or placebo were used – a lower re-hospitalization rate was seen in the probiotic group compared to the placebo group.


The Finnish research group compared the microbiota of 28 patients who underwent the first psychotic episode with the microbiota of 16 people without such experience. It turned out, that although no significant differences were found between the total number of bacteria, the proportions between their individual types were significant and correlated with the severity of the symptoms. In addition, a subgroup of patients who underwent the first psychotic episode with the most pronounced differences in microflora when compared to the control group, showed poor response to treatment after 12 months of follow-up.

Neurodegenerative diseases

Increasingly, the correlation between the intestinal microbiota and the central nervous system is being studied in the context of neurodegenerative diseases such as Parkinson’s or Alzheimer’s disease, for which there is still no effective treatment. Clinical trials with the use of probiotics in 60 people with Parkinson’s disease showed that ingestion of probiotics had a beneficial effect on movement related symptoms as well as some metabolic parameters such as CRP, glutathione level and insulin metabolism. A similar study was also carried out in 60 people struggling with Alzheimer’s disease – an improvement in symptoms described using the MMSE (Mini-Mental State Examination) scale was observed, which indicates a large potential in the application of the probiotics.

Although many elements and mechanisms that are part of the regulation of the gut-brain axis are still waiting to be discovered, we are now able to clearly state that health nutrition and proper bowel function is the foundation for a well-functioning and efficient organism.

Before buying probiotics, pay attention to some basic information that will allow you to choose a good product. Currently, in stores you can find many different products that have not been properly tested, so pay attention to:

  • List of bacterial species and strains. Not all bacteria used in probiotics affect mental health
  • The number of bacteria in the product. Currently, the optimal dose of probiotics has not been determined, but most tests use probiotics containing a minimum of 1 billion bacteria in a daily dose.
  • Research, that was carried out on it. In this way, it will be much easier for you to choose the supplement to your personal preferences. 



  • https://www.ncbi.nlm.nih.gov/pubmed/31530002
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6225396/
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6378305/