Anxiety, Depression and Gut Health



It’s National Mental Health Awareness Week this week, so it seemed appropriate that this blog will discuss the link between anxiety, depression and gut health.


Studies show that as many as half of those diagnosed with IBS, also suffer from psychological disorders including anxiety and depression. From my experience working with IBS sufferers, I believe the correlation is much greater than what these studies show. One of the questions I ask all of my clients is if they have ever been diagnosed with mental health conditions, and nearly every single person says yes. However, there is a lot of misunderstanding around how this impacts gut health. Many of those diagnosed with IBS have been led to believe that the condition is caused by their mental health, but more recent research is showing that the ‘gut-brain axis’ is actually a two way street, where the imbalances in your gut directly affects what’s happening in your brain, and vice versa.


What is the ‘gut-brain axis’?


The ‘gut-brain axis’ is the bidirectional link between the autonomic nervous system (ANS) and the enteric nervous system (ENS) of the body. Both the ANS and ENS can impact mental health and IBS in different ways.


Enteric Nervous system (ENS)

The digestive system has its own nervous system called the enteric nervous system (ENS), which is two thin layers of more than 100 million nerve cells lining your gastrointestinal tract from esophagus to rectum. It is sometimes referred to as the second brain but unlike the brain, Its main role is controlling digestion, from swallowing to the release of enzymes that break down food to the control of blood flow that helps with nutrient absorption to elimination.

The ENS may trigger big emotional shifts experienced by people coping with IBS. For decades, researchers and doctors thought that anxiety and depression contributed to these problems. But studies show that it may also work the other way around. Researchers are finding evidence that irritation (caused by poor diet, eating habits, dysbiosis and bacterial overgrowths) in the gastrointestinal system may send signals to the central nervous system (CNS) that trigger mood changes. There have even more recently been specific strains of bacteria found in our guts that have been found in higher levels in those with clinical depression. These new findings may explain why a higher-than-normal percentage of people with IBS and functional bowel problems develop depression and anxiety.

The Autonomic Nervous System (ANS)

The autonomic nervous system has two branches -

the sympathetic nervous system: involved in the ‘fight or flight’ response. This branch of the nervous system is really an evolutionary advantage, which ensures that we can summon up the energy during times of great stress to run away from whatever threat in order to survive. And it's meant to last only for short bursts or short duration that releases stress hormones that divert the blood flow away from the organs and more towards the big muscles so that we could run away. During this time the usual automatic processes like digestion get put on standby because your body is saying this is no time to digest food, this is the time to survive and run away. The problem is, most people live pretty busy, stressful lives these days, and our nervous system isn’t great at distinguishing between being chased by a tiger and having an inbox full of emails that desperately need to be answered, but your family is also expecting dinner to be on the table soon. Both of these situations are stressful and so our body responds the same, by focusing your body’s resources on removing the “threat”, and putting automated processes like digestion on the backburner. This is exactly how mental health conditions like anxiety can drive IBS symptoms, as most people who suffer with anxiety are constantly stuck in a state of ‘fight or flight’.

Parasympathetic nervous system - This is essentially the opposite of the sympathetic nervous system, and often referred to as ‘rest and digest’. It controls bodily functions when a person is at rest. Some of its activities include stimulating digestion, activating metabolism, and helping the body relax. This is the state you want to be in when eating to promote better digestion, yet many IBS sufferers (especially those with anxiety) are stuck in ‘fight or flight’.

As you can see, the gut-brain connection is a two way street, where the gut can impact mood and emotions, and the brain can impact digestion.


What you can do about it



The key to overcoming gut-brain axis issues is to work on both the physical gut imbalances related to the ENS, that have the potential to impact mood, as well as work on your nervous system “state” to help promote better digestion. Basically, work on both directions of the gut-brain axis.


Direction 1 (gut-to-brain) -