Question

How does the gut microbiome influence mental health?

I recently read a really interesting book called "Brain Maker" by Dr. David Perlmutter, and my interest in this concept of the gut-brain axis has significantly intensified. In the book, he mentioned the links between an unhealthy gut and autism, dementia, Alzheimer's, depression, anxiety, and several other mental health disorders that I never would have associated with gut bacteria prior to reading it. This article from NCBI discusses the gut microbiome and its effects on mental health issues like depression and anxiety that have been of increasing public interest over the last several years. How is this possible? And what can we do about it? If the key to treatment of mental health disorders stems from the gut, why do doctors continue over-prescribing SSRIs and other medications that have nothing to do with the gut?  

please list any sources

Answer 1

According to research it is found that there is some co-relation between the gut microflora and mental health. A bad microflora population might lead to number of mental disorders like anxiety, depression, autism, dementia etc. It is said that the microbiome that is healthy for the gut might be used to produce new class of pyschobiotics which might help in treating mental issues. The idea that microgut is connected to mental health stems from research done in 19^th and 20^th centuries where it was believed that accumulation of waste in the colon led to toxication of the brain which in turn led to depression, anxiety and other mental issues.

The scientists are researching on the fact that microflora that is present in the intestines might have a major impact on the brain. This is also known as gut-brain axis which is bi-directional which means both are sort of dependent on one another. The brain acts on the gastrointestinal and immune functions that helps in shaping up the microflora for the gut. In a other way, gut is responsible for making neuroactive compounds that includes neurotransmitters and metabolites that impact the brain. There is a strong bidirectional relationship between the brain and the gut.

There are different types of ways by which this bidirectional relationship can be maintained like presence of the vagus nerve. The nerve connectes the brain and the digestive tract and hence it might help the microbial compounds to communicate through it. It was also found by scients that the gut microbes helps in controlling the leakage from the lining of the intestine and blood brain barrier and hence protects the brain.

There are many experiment conducted on the mice where it was made germ-line free and in such cases the hormones released by the hypothalamic-pituitary adrenal axis was not functional. This showed a direct connection of how the gut microflora can actually impact the brain. It was also found that people who has more intestinal illness has higher rate of mental isssues. There have been many evidence that states the direct connection.

However, doctors are yet to prescribe such solution for mental problems as the dots are yet to be connected and a lot of research still needs to be done. The use of the probiotics or microbiome of gut is still in question as it is not yet regulated by FDA and not proper evidence is there linking the impact or affect. Due to lack of any sort of regulations, patients are still prescribed mood altering drugs instead of introducing the patient to a whole range of edible gut microflora.