Want Stronger Brain Health? Go With Your Gut! – Part 2

Written by Anil Bajnath, MD
Posted September 2, 2021

Dear Longevity Insider,

Your gut and brain have a close-knit relationship.

Gut health is essential to mental health because it affects our mood, emotions, ability to handle stress, and symptoms of conditions such as autism spectrum disorder (ASD). The gut-brain axis is a two-way street, and both of these "roads" are connected. When one road is in bad condition, it affects the other road as well. This can cause inflammation, stress, and disease. As we learned in our inflammation series, inflammation can cause an increase in the release of cortisol from the adrenal glands. This is not good for us because too much cortisol disrupts our body and brain functions.

Stress also plays a large role in our gut-brain axis. Not only does stress cause our adrenal glands to release cortisol, but it can also lead to poor diet decisions that throw off your gut bacteria. Anxiety and depression are associated with changes in microbiome composition, as well as with increased gut permeability allowing lipopolysaccharides (LPS). LPS refers to metabolic endotoxemia. LPS are not only harmful to your gut, but they are also a primary cell wall component of gram-negative bacteria. So as stress and anxiety increase your gut permeability and release lipopolysaccharides into the bloodstream, these can cause inflammation in the brain leading to more cortisol production and an overall increase in inflammation throughout the body.


Maintaining good gut health is important, as the gut microbiome may help with stress responses by influencing the synthesis of neurotransmitters and neuropeptides that have an impact on homeostasis, neuroinflammation, and neuronal plasticity. Recent research shows that the gut microbiome may also have an impact on neurogenesis. Neurogenesis is a vital process to maintaining mental health and is the generation of neurons from neural stem cells. Gut microbiota close to the enteric nervous system (ENS) exerts substantial influence over it. The gut microbiome can stimulate vagal afferent neurons by releasing transmitters such as 5-HT, acetylcholine, and norepinephrine. The gut microbiome can also stimulate afferent neurons in the submucosal and myenteric plexus of the ENS to release a range of chemicals including neuropeptides (e.g., substance P, cholecystokinin).


Research is still underway on how to improve the balance of gut microbiota or modulate the gut-brain axis. Gut microbiome therapy may be used in some future medical therapies for psychiatric disorders, autism, and neurodegenerative disease.

Biological psychiatry is currently studying the gut-brain axis by focusing on how metabolites from the microbiome can impact neurotransmitter function, synaptic plasticity, and neuroinflammation. The gut-brain axis is being studied in clinical psychiatry for treating conditions like depression, anxiety disorders, and autism spectrum disorder (ASD). Although research is still underway on how to improve the balance of gut microbiota or modulate the gut-brain axis, some recent studies have been completed for gut microbiome therapy.


Diet is one of the most important modifying factors of the microbiota-gut-brain axis. If you are experiencing any gastrointestinal symptoms (gas, bloating, stomach pain) as well as mental health issues such as anxiety or depression, then a Gut-Brain Axis evaluation is recommended to determine if there is an imbalance in neurotransmitters due to the gut-brain axis not functioning efficiently. The most important thing that you can do if you're not feeling like yourself is to visit your health provider and get these tests done!

In the meantime, it is important to improve your gut-brain axis by trying the following tips to get back on track:

  • Get enough fiber in your diet from fruits and vegetables.
  • Get rid of the bad bacteria and yeast with beneficial bacteria.
  • Reduce stress as much as possible and practice self-care.
  • Exercise regularly.
  • Practice mindfulness.


The gut-brain axis is the intersection of your gut and brain that affect each other. When your gut-brain axis isn't set up correctly, it can be harmful to your overall well-being.  And the #1 most dangerous food in the American diet completely sabotages gut health. The sad part is, most people think this ingredient is good for them.

To your longevity,

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