Want Stronger Brain Health? Go With Your Gut! – Part 1

Written by Anil Bajnath, MD
Posted August 31, 2021

Dear Longevity Insider,

The gut-brain axis is a term that refers to the two-way communication system between the gastrointestinal tract and the central nervous system. The gut-brain axis can be disrupted by many different factors, including stress. With an unhealthy gut microbiome (bacteria) in your digestive tract, you are more susceptible to many health conditions. These include inflammation, metabolic syndrome, obesity, type 2 diabetes, depression or anxiety disorders, and neurodegenerative diseases such as Alzheimer’s disease or Parkinson’s disease.

This week, we'll explore how a healthy diet can help heal your gut microbiome by providing proper nourishment for good bacteria, while helping to remove bad bacteria from your body through natural detoxification pathways.


The gut-brain axis has recently been coined as the new "Central Nervous System," which is a complex system of communication between the enteric nervous system in the gut and the central nervous system (CNS) in your brain. The gut-brain axis is responsible for maintaining homeostasis between the autonomic nervous system and the immune system, regulating substances that may act as neurotransmitters. When the gut-brain axis is not functioning optimally, this can lead to a range of problems including depression, anxiety, and stress-related disorders. Gut bacteria are responsible for maintaining the gut-brain axis by producing neurotransmitters that can stimulate specific cells in the gut which can then send signals back to the brain through various neurological pathways.

Strong evidence suggests that gut microbiota has an important role in bidirectional interactions between the gut and the nervous system. It interacts with the CNS by regulating brain chemistry and influencing neuro-endocrine systems associated with stress response, anxiety, and memory function. Gut microbiota can also influence brain function through the hypothalamic-pituitary-adrenal axis and autonomic nervous system. The hypothalamic-pituitary-adrenal axis is the major neuroendocrine system that mediates the stress response. Our autonomic nervous system is made up of the sympathetic nervous system (SNS), which is activated by stress and can stimulate colonic relaxation, vasoconstriction, and ileocaecal transit. Gut microbiota also interacts with immune cells in the gut, and these interactions have been shown to affect brain function. This has implications for mood disorders such as anxiety and depression that we will discuss later in this blog. Gut microbiota can also influence brain function through the autonomic nervous system, which regulates all of our unconscious actions (our heart rate, breathing pattern, etc).

Another factor worth mentioning is neurotransmitters. Neurotransmitters are essentially electrical signals in the brain that help us communicate and regulate many bodily functions including mood, emotions, the ability to handle stress, and more. When our gut-health axis is off, our neurotransmitter signals can be disrupted, which causes a cascade of brain issues. To make this simple, we are going to focus on serotonin as an example of what our gut-health axis can do for us. Serotonin is a neurotransmitter that regulates mood and behavior. When serotonin levels get messed up, it not only causes anxiety but also disrupts sleep patterns and more.

We'll take a closer look at the strong relationship bewteen the gut and mental health on Thursday.

Meanwhile, take the time to assess your mood and how you feel. Have you been feeling, tired, fat, and sick? It's probably because of this.

To your longevity,

Anil Bajnath MD
CEO/Founder, Institute for Human Optimization
Chief Medical Officer, Longevity Insider HQ