How Your Gut Health Affects Your Mental Health

We all know about the importance of eating healthy and nutritious foods, having a balanced diet, and drinking enough water. As many still try fad diets and fail to break bad habits, do we really understand the effect this not only has on our body but also our mental health too? The world’s leading expert in medically important fungus, Dr Mahmoud Ghannoum is pioneering a movement that educates us on the importance of digestive health. The doctor, who hails from Lebanon and is a best-selling author explains more.

How is gut health linked to mental health?

To start, we need to acknowledge the recent discoveries showing that the brain and the gut communicate through what we call Gut-Brain-Skin Axis. The gut-brain axis, or GBA, is a term used to describe the communication between the brain (the central nervous system, or CNS) and the gut (the enteric nervous system, or ENS). This communication involves signaling between the endocrine system (the hypothalamic-pituitary-adrenal axis, or HPA axis) and the autonomic nervous system (ANS). The main thing to know is that our brain talks to our gut and vice versa. This is a two-way communication. It is not that our brain talks and our gut listens. No, they are having a conversation, with each partner listening to the other and taking their turn.

The first evidence of the GBA, came from the work of an army surgeon who studied gastric juices secreted by fistula occurring in the stomach. It was found that our moods are related to intestinal function.

We used to think that the brain controls everything that happens in our bodies. Now we are discovering that the microbiota (this refers to the multitude of organisms including bacteria and fungi that reside on and in our bodies including the gut) affect the brain. In fact, the back and forth communication between the gut microbiota and components of the GBA influences normal homeostasis (state of health) and may contribute to the risk of disease. Based on these discoveries, scientists came out with a new definition of our brain called “Whole Brain,” which is made up of Brain + Microbiome + Gut. Others are even calling the microbiome in our gut a “Second Brain.”

How Does the gut talk to our Brain?

This gut-brain communication is facilitated by a number of biochemical and hormonal interactions in nature; systems including the autonomic nervous system (ANS), the enteric nervous system (ENS), the neuroendocrine system, and the immune system. A pivotal player in this communication is the vagus nerve. This nerve runs from the brain through the face and thorax and through the abdomen and is a primary connection between the brain and intestinal tract. In fact, the vagus nerve mediates CNS effects on behavior.

The result is that gut health and brain health are linked, in health and in dysfunction. The condition of your gut influences how you feel, how you present yourself, how motivated you are, and your cognitive function. The condition of your brain also influences your microbial composition and your level of imbalance (called dysbiosis). The HPA axis gets involved in any kind of stress response, pumping out cortisol, one of the primary stress hormones, to help the body deal with danger. Because of the GBA, there is always a gastrointestinal link to the stress response (this is why you may get “butterflies in your stomach,” or a “nervous stomach,”. Importantly, many aspects of this gut-brain unifying theory have recently been validated.

Can good gut health help improve mental health?

Recent studies have shown that having a healthy gut is associated with good mental health and vice versa. In fact, the National Digestion Information Clearinghouse estimates that 50 to 90% of patients with irritable bowel syndrome (IBS)  who seek treatment have a psychiatric disorder such as anxiety or depression.

Evidence to support the idea that gut health is linked to mental state was discovered more than 70 years ago by Stokes and Pillsbury, who proved an overlap between gastrointestinal dysfunction and depression and anxiety. They proposed that emotional states might alter the normal intestinal microflora and increase intestinal permeability contributing to inflammation. Based on this, they advocated the consumption of the probiotic Lactobacillus acidophilus as a remedy.

In agreement with their findings, recent research has also associated depression with the constitution, amount, and species of intestinal microbiota.

With all of this in mind, it’s clear that having good gut health will positively impact our mental health.

Does the stress caused during this pandemic affect gut health?

The COVID-19 pandemic is an event that no one has ever experienced before. With social distancing, we are confined to our homes, unable to see anyone, perhaps even our loved ones. The effect of this situation is directly impacting our mental health, in some cases manifesting as depression and anxiety. Significant stressors include the uncertainty surrounding the worldwide pandemic along with feelings of fear, isolation, stress from working at home, disrupted workplaces and schedules, and anxiety about future events and decisions.

This stress contributes to negative gastrointestinal effects. Research has shown that stress impacts the gut directly through the GBA, altering the microbiome. This alteration includes reducing the abundance of beneficial microbes in our gut. Stress can also promote inflammation through microbiome alteration.  Many studies have demonstrated the microbiome effect on the stress response – improving gut health has been shown to calm anxiety-like behaviors, and microbiome disruptions have been shown to cause anxiety-like behavior. This back-and-forth is highly complex, but the bottom line is that stress can increase gut imbalance, and gut imbalance can increase stress.

How can you improve the health of your gut?

Having a healthy gut is linked to having a healthy, balanced gut microbiome. Achieving this can be attained through adopting a healthy diet and lifestyle. Specifically, eating more nutrient-dense meals that are high in fiber and vegetables, while cutting back on fast-foods and refined sugars, appears to be sufficient for avoiding the potentially negative effects of a “junk food” diet. Besides diet, change in lifestyle (particularly exercise, stress reduction, and better sleep) will also help to tackle mood and depression issues.

The take-home message: Having a balanced microbiome is all in your hands. Our gut is like a garden; to have gorgeous roses you need to tend to them, otherwise, you will have weeds. The same applies to our gut; when we feed our beneficial microbes, we stop the growth of the pathogens or “bad ones.”