The complexity of the Gut
While medicine continues to view the digestive system as being largely independent of the brain, we now know that these two organs are intricately connected with each other forming the gut-brain axis through what is called the Vagus Nerve. This communication network may be more important for your overall health and well being than you ever have imagined.
Recent studies suggest that in close interactions with its resident microbes, the gut can influence our basic emotions, our pain sensitivity, our social interactions and even decision making.
The gut as the ‘second brain’
The gastrointestinal system is the largest immune organ and in healthy conditions our gut has a mucus layer barrier protecting against foreign bacteria and antigens. The lining of our gut is stuffed with a huge number of endocrine cells which are capable to communicate with the brain by releasing neurotransmitters (endogenous chemicals that transmit signals from a neuron to a cell in order to stimulate of inhibit brain activity).
However, when the diversity of gut microbiota is affected by stress, diet and medicine, it can potentially influence the stress-related behaviors, such as anxiety and depression.
Healthy gut, healthy mind
The gut stores 95 percent of one of the most important neurotransmitters for our well-being – Serotonin. This is not only essential for normal intestinal functions (moving food through our GI, but it also plays a crucial role in vital functions such as: sleep, appetite, pain sensitivity, mood and overall well-being
Within a healthy gut, friendly microrganisms have the ability to generate the “feel good” mood by increasing GABA receptors in the brain, which is a neurotransmitter responsible for reducing brain stress and excitability.
Dopamine is a neurotransmitter that is also largely dependent on a healthy gut to be produced. It is responsible for regulating our Reward System – appetite regulation and provides the drive and motivation to search for food. It is believed that the drive to eat so-called comfort food and the concept of food addiction are both excellent examples of behaviors that could potentially be manipulated by certain types of gut microbiota to provide them with preferred foods.
Said that, it’s clear that gut bacteria significantly influences gut-brain communication and when the gut is healthy it has the potential to regulate mood and feelings.
Probiotics for Mood: Enhancing the Gut-Brain Connection with Psychobiotics
Pychobiotics is the term used for specific strains of probiotics (‘good’ bacterias) that have been proven to boost mood, decrease anxiety, and ease depression, among other benefits.
The daily consumption of these probiotics have been shown to produce a health benefit in patients suffering from psychiatric illness, as well as anyone suffering from chronic stress, low mood, or anxiety-like symptoms. Researchers also emphasize the importance of having an abundant and diverse microbiota for optimizing brain health.
How to maintain a healthy gut?
Again…It is essential to maintain a healthy diet with plenty of vitamins and fibre to keep our gut microbiota receiving important nutrients to work on its optimum; being careful with food safety to avoid the exposure to foreign bacteria; being aware of any signal of food intolerance; being careful with anti nutrient foods that can cause a ‘leaky gut’; and adding foods that will help to build up a healthy gut, such as:
Fermented foods are the best route to optimal digestive health, as long as you eat the traditionally made, unpasteurized versions. Healthy choices include: fermented grass-fed organic milk such as kefir, various pickled fermentations of cabbage, turnips, eggplant, cucumbers, onions, squash, and carrots, and natto (fermented soy).
Probiotic supplement. Although I’m not a major proponent of taking many supplements (as I believe the majority of your nutrients need to come from food), probiotics is an exception if you don’t eat fermented foods on a regular basis.
Javier A. Bravo, et al. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. PNAS 2011 : 1102999108v1-201102999.
Komaroff A.L. The gut brain connection. Harvard Health Publications; 2012. http://www.health.harvard.edu/diseases-and-conditions/the-gut-brain-connection
Emeran A. Mayer; Kirsten Tillisch; Arpana Gupta. Gut/brain axis and the microbiota. J Clin Invest. 2015;125(3):926-938. doi:10.1172/JCI76304.
Alper Evrensel and Mehmet Emin Ceylan. The Gut-Brain Axis: The Missing Link in Depression. Clin Psychopharmacol Neurosci. 2015 December; 13(3): 239–244.