The Gut Microbiome Directly Affects Mental Health

In 2019, 970 million people were reported to have mental health disorders and has most likely only risen. The rise of mental health conditions has created a public health concern and it is crucial to find solutions. This research article is a review paper, having pulled from all articles on the gut microbiome and mental health on PubMed and Web of Science Core Collection, and it aims to help the public make informed choices on the foods they intake. Additionally, the results they summarize have exciting possibilities for the future of treating mental health disorders.

Introduction

What is the gut microbiome? It is essentially an ecosystem of microbes that live in the intestine. Microbes are microscopic living organisms and in the intestine, are usually bacteria and fungi. Though bacteria and fungi may have negative connotations, most of the microbes in the human body are essential for good health.

In this review paper, researchers studied gut microbiota (another word for gut microbiome) and its metabolites (small molecules produced by bacteria). As researchers read over many papers on this topic, they found significance evidence pointing to the significance of gut microbiota on mental health.

It was also found that the gut microbiome regulated and even produced neurotransmitters, such as serotonin, dopamine, and glutamate. These neurotransmitters are chemicals that carry signals throughout the body and are linked to many mental health disorders. Therefore, the fact that the gut microbiome can influence neurotransmitters shows that it directly impacts mental health.

A study confirms this idea. In around a diet high in high fruits and vegetables was found to be positively associated with the mental health of about 500,000 middle-aged adults.

With these results, there is a potential way to prevent or treat mental health disorders by targeting the gut microbiome. Currently, the only treatments are pharmacotherapy (drugs) and psychotherapy. However, these treatments have limited effectiveness and drugs often have unpleasant side effects. This new information hints at a future of treatments that consist of natural foods. This topic is a rising question in the food science, nutrition, psychology, and psychiatry fields.

Anxiety

Anxiety is a fairly common mental health disorder and is sometimes linked to social exclusion. Studies showed that in those who experienced high social exclusion, the amount of Prevotella, Firmicutes, and Bacteroidetes increased. Additionally, it was found that Faecalibacterium decreased.

The most notable result was that in those with anxiety, the microbiome was less rich in microbes and had less diversity.

Depression

In depression, gut microbiome dysbiosis was related to the occurence or development of depression. Dysbiosis is when there is an imbalance in the composition of the microbiome and typically, the amount of harmful bacteria increases while beneficial bacteria decreases.

• Dysbiosis is associated with other chronic diseases as well:

  • Obesity

  • Type 1 Diabetes

  • Certain cancers

In patients, Paraprevotella, Prevotella, Klebsiella, and Clostridium were positively associated with depression. Though the gut microbiomes varied in patients across studies, they were noticeably different from those without clinical depression. With further studies, the gut microbiome can be a target for treating depression.

Schizophrenia

The results pertaining to patients with schizophrenia were surprising. Special gut bacteria (Lactobacillus fermentum, Enterococcus faecium, and Alkaliphilus oremlandii) were found. This is noticeably groundbreaking because these bacteria are not found in those without schizophrenia. Lots of beneficial bacteria were missing from patients and the key to treating schizophrenia may be introducing those bacteria into the body.

Figure 1. The relationships of gut microbiota and mental disorders.

Conclusion

The results summarized in this review paper have promising answers for mental health disorder treatments and strengthens the idea that gut microbiome has an important role in treating mental health. In order to produce further results that can be applied to everyone, researchers must begin to look at different races, genders, and ages. This will help narrow down treatments that can be personalized.

In closing, good diet is not only beneficial for physical health but for mental health as well. Additionally, mental health disorders cannot be treated solely through a healthy, balanced diet. However, there are signs that point to a future treatment of natural food products that will make a big impact.