The brain has a direct connection to the stomach and intestines.  Just as the brain sends signals to the stomach to release enzymes with thoughts of foods, the connection goes in both directions.  An intestine with issues sends signals to the brain, causing anxiety, stress or depression.  

How does it work? 

Communication between the brain and the gut occurs between the nervous system, hormones, and the immune system. The vagus nerve controls the messages to the gut, heart, lungs, and other vital organs and is the gut’s direct connection to the brain. Neurotransmitters and hormones send chemical messages between the gut and brain. These messages can become affected by the gut microbiome.  Microorganisms in the gut, microbiome, help regulate the immune response. Thousands of bacteria, both “good” and “bad,” populate the gut and should exist in a balance in favor of the “good” bacteria preventing overgrowth of the “bad.” Disruption to the healthy balance of microbiome can cause the immune system to overreact and contribute to inflammation, leading to the development of symptoms in the body and the brain.  Anxiety and depression can cause changes to the gut microbiome because of the result of what happens due to the response from stress. 

Anxiety and Depression 

Most people experience some anxiety and depression throughout their lives, but when the feelings are intense, feeling hopeless, and anxious for many days at a time, it can be something more.  Anxiety is intense, excessive, and persistent worry and fear about everyday situations. Fast heart rate, rapid breathing, sweating, and feeling tired are symptoms associated with anxiety. Depression is a mental health disorder characterized by a persistently depressed mood or loss of interest in everyday activities, which causes significant impairment to daily life.  Feeling tired, worthless, having a hard time focusing, unable to sleep, or too much sleep, no interest in pleasure activities, or feeling slowed down are symptoms associated with depression.  

Common Medications Used to Treat Anxiety and Depression

Several drugs are used to treat depression and anxiety. Some common ones are:

  • Selective serotonin reuptake inhibitors (SSRI)
  • Selective serotonin & norepinephrine inhibitors (SNRI)
  • Anti-anxiety drugs like benzodiazepines 

While these drugs are common, they can carry a risk of addiction or tolerance and may need higher and higher doses to achieve the same effect, so long-term use is not desirable.  These drugs may also be used in combination with one another to boost the effects.  

A theory of the cause of depression is that low levels of the neurotransmitter serotonin are the cause.  SSRI’s work by stopping the reuptake of the neurotransmitter into the neuron, or nerve cell, where it is released. SSRI’s don’t work for much of the population, and it may be due to differences in genetics, environment, or the structure of neurons in those individuals. 

Neurotransmitters and the Gut

Serotonin is known as a brain neurotransmitter. However, it is estimated that 90% of serotonin is made in the digestive tract.  Gut microbes modulate serotonin levels as well as other neurotransmitters like epinephrine, norepinephrine, and dopamine. The gut also produces a neurotransmitter called GABA (gamma-aminobutyric acid) which is responsible for controlling fear and anxiety.  Neurotransmitters in the gut play a major role in maintaining balance and aiding in nutrient absorption, blood flow, immune system, and overall gut motility.  

Factors that impact neurotransmitter deficiency 

  • Diet – maintaining a healthy balance requires a healthy diet, ensuring that the body has enough energy through carbs, fats, and proteins as well as micronutrients to provide the cofactors for the pathways
  • Chronic stress – the body’s physiological reaction to stress is mediated by cortisol. Feeling stressed all of the time takes a toll on the body and disrupts the neurochemical balance.  
  • Toxic substances – heavy metals, pesticides, drug use, and some prescription medications cause damage to nerve cells that make neurotransmitters.
  • Certain substances – caffeine, alcohol, nicotine, aspartame are some substances that may deplete serotonin and other neurotransmitters 

All of these factors, combined with genetics, can lead to faulty metabolism and digestive issues which impair absorption and breakdown of food so that the body is unable to get the fuel it needs to build neurotransmitters.  

Testing for Neurotransmitter and Gut Health

Diagnostic testing is available to uncover some of the causes of your symptoms.  Two tests available are GI-Map and Neurotransmitter testing. GI-Map is done through stool testing to look for biomarkers in the gut, like h. Pylori, bacteria, parasites, viruses, and more to focus on the specific microbes that tend to disturb the normal balance of your microbiome.  Neurotransmitter testing helps to identify imbalances associated with anxiety and depression. This diagnostic approach tests for specific neurotransmitter levels like serotonin, norepinephrine, epinephrine, glutamate, dopamine, and GABA to clarify root issues.  

Natural Ways to Balance the Gut-Brain Connection

  • Ashwagandha – this stress-relieving herb helps to protect the nervous system and works as an antioxidant to seek out and destroy free radicals.  Ashwagandha helps reduce cortisol levels, enhances GABA receptors, and serotonin in the brain. 
  • L-Theanine – an amino acid extracted from green tea, l-theanine helps to increase the synthesis of GABA.  Increased GABA leads to higher levels of dopamine and serotonin, resulting in feelings of calm and well-being.  
  • Vitamin B6 – plays an important role in mood regulation.  B6 is necessary for creating neurotransmitters like serotonin, dopamine, and gamma-aminobutyric acid (GABA).  
  • Magnesium – vital to nearly every process in the body and susceptible to increased stress, magnesium levels diminish in the presence of high stress.  Replenishing the supply is important in helping reduce anxiety and depression. Magnesium plays a role in many pathways, enzymes, hormones, and neurotransmitters, making it one of the most important nutrients for the body.  
  • Mucuna Pruriens –  also known as dopa bean, cowitch, sea beans or velvet beans, mucuna pruriens is a natural Indian herb which helps with depression.  It contains high levels of l-dopa, a precursor to dopamine. As an adaptogenic herb, it helps regulate hormones to help the body manage stress. 
  • L-Tyrosine – a precursor to catecholamines, l-tyrosine can influence the synthesis of dopamine, epinephrine, and norepinephrine.  Because stress can affect reasoning, memory, and attention, increasing these neurotransmitters may help these functions in stressful situations.  
  • 5-HTP – a natural precursor to serotonin, this can boost levels which may help to reduce anxiety and depression as low serotonin levels are associated with depression, anxiety, sleep disorders, and weight gain. 
  • GABA – Gamma-aminobutyric acid is an amino acid produced in the brain, functions as a neurotransmitter, and facilitates communication between brain cells.  Its big role in the body is to reduce activity in the brain and nervous system. By inhibiting neural activity, GABA facilitates sleep, reduces mental and physical stress, lowers anxiety, and creates a calming mood.   
  • L-glutamine – an amino acid that is essential to maintaining the health and growth of cells and improving gut permeability.  L-glutamine is the precursor to GABA. It also supplies energy to immune and intestinal cells, especially during stressful times.  
  • Probiotics – beneficial microorganisms that promote a healthier gut.  Probiotics help to boost mood and protect the body against harmful physical and mental effects of stress. 

Recommended Supplements by INEVO Body

Calm – Supports serotonin levels and balances mood

Digest IB – Supports the anxiety associated with IBS and reduces bloating

Digestevo Probiotics – Supports healthy gut microbiome 

InflammaBolix Shake – The go-to meal replacement shake supporting detoxification and gut health

NeuroXCore – Bioavailable source of magnesium supporting relaxation, stress and neurotransmitter production

Back to Blog

Take The First Steps

If you want to begin feeling better in your own body, BODY by AIM360 is here for you. Just set up your free consultation with us, and health will follow.

Contact Us
Contact us media


Accessibility: If you are vision-impaired or have some other impairment covered by the Americans with Disabilities Act or a similar law, and you wish to discuss potential accommodations related to using this website, please contact our Accessibility Manager at 412.347.4442.
Contact Us