STUDENT CONTRIBUTOR: Dorothy Perelman | Food & Nutrition, Ryerson University
November 16, 2020
We often hear about the significant physiological implications of diabetes - from high blood sugar levels to retinopathy to organ damage. What's missing is attention paid to the psychological effects. Mental health in diabetes is a serious issue because many individuals living with this chronic disease often experience cognitive dysfunction, memory disorders and mood fluctuations.
In fact, depression is twice as common for individuals diagnosed with diabetes compared to the general population. Have you ever wondered why you are unexplainably upset some days and anxious others? Or why there are times you can get things done with laser focus, and in the next moment you can’t seem to sit still? Well, we are here to provide you with the likely culprit underlying many mood disorders. We'll even go one step further and suggest a practical solution.
Let me begin by explaining why people - challenged by diabetes, or not - may be experiencing symptoms like anxiety, depression or ADHD. The nervous system consists of the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves). The Enteric nervous system is one part of the peripheral nervous system. Many of these problems can actually be attributed to our gut microbiome; part of the enteric nervous system (ENS).
What is the enteric nervous system (ENS)?
Have you ever heard of the sayings “trust your gut” or “go with your gut”? It turns out there just might be some truth behind these clichés. Within the gastrointestinal system - a.k.a. the gut - there is a neural network that includes neurons, neurotransmitters and proteins that are identical to many of those found in our brain. This neural network is known as the enteric nervous system, or ENS.
The ENS spans the esophagus, stomach, intestines as well as the colon. It functions independently of our brain. The ENS controls and manages every part of digestion such as smooth muscle contractions and digestive secretions. If the ENS doesn't work right, the stomach cannot digest, absorb or excrete food properly (1).
Why is the ENS so important for our well-being?
Digestion and absorption of certain nutrients is critical for the body's ability to make neurotransmitters; the chemical messengers that enable nerves to communicate with the rest of the body. Neurotransmitters like serotonin (the happy hormone) or dopamine (the feel-good hormone) impact mood and behaviour.
So, if the enteric nervous system plays a role in making neurotransmitters, and neurotransmitters impact cognitive functions, then the enteric system (our gut) has the power to impact mood! The ENS also directly communicates with the brain - and vice versa - through the vagus nerve. There is an evident link between the gut and the brain. This connection is called the gut-brain axis (2).
If we know that the gut influences our brain, so it's probably important that our gut functions well, right? But what makes a heathy gut and how do we keep it that way?
The Gut Microbiome
Our GI tract contains contains trillions of microbes known as the gut microbiome, or gut flora. Your unique microbiome is influenced by numerous factors such as genetics, age, sex, diet, and lifestyle.
The organisms within your gut have the power to alter your mood, behaviour, physiology, metabolic functions and immune system. However, the nature of these implications - whether the microbiome affects health positively or negatively - depends on the unique classes of bacteria which encompass the gut, itself.
Specifically, a 'well-oiled' gut is dependent on the ratio of symbionts (good bacteria) to pathobionts (bad bacteria). Dysbiosis happens when the concentration of harmful bacteria in the gut is greater than the good, and an unbalanced gut is associated with the development of mood disorders like anxiety and depression. Dysbiosis may contribute to development of chronic diseases like obesity and type 2 diabetes, as well.
Although no two microbiomes are exactly alike, the composition of the gut flora differs in “healthy” individuals as compared to those impacted by illness. One study even found that men with type 2 diabetes had lower levels of specific gut bacteria, compared to non-diabetic control subjects. These alterations in the gut microbiome may contribute to depression, anxiety, irritability and other mood disorders often associated with diabetes.
Evidently a healthy gut microbiome is important, to say the least, but how can we help ensure the composition of the microbiome is optimal for physical and mental health?
Here's Where Probiotics Come In...
Probiotics are living microorganisms that restore the balance of good vs. bad bacteria in the gut, thus contributing to overall health. Probiotics are found in fermented foods like yogurt, kefir, kombucha, pickles and sauerkraut. Probiotics are also available in supplemental form, and are simple to buy from most local grocery stores and pharmacies.
Probiotics may decrease inflammation, increase the level of antioxidant enzymes and reduce oxidative stress within the body. This is especially important for individuals living with diabetes, as they often have high levels of oxidative stress, which - in turn - may cause learning impairments, alterations in memory and cognitive disorders. In fact, one study found that the administration of probiotics positively impacted spatial learning, memory and hippocampus function, while also lowering oxidative stress biomarkers.
Research shows that probiotics are a very important part of a healthy, balanced diet and may be a great way to address many mood imbalances that impair quality of life. That being said, we are not recommending probiotics as substitutes for treatment of serious mental illnesses. Always consult a Registered Dietitian, psychologist or your family doctor for your unique health concerns.
John B. Furness (2007) Enteric nervous system. Scholarpedia, 2(10):4064.
Carabotti, M., Scirocco, A., Maselli, M. A., & Severi, C. (2015). The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of gastroenterology, 28(2), 203–209.