co-written by Rick Olazabal, BSc, BN
The brain-gut connection is one of my favourite topics.
It is a perhaps the epitome of how everything in the body is related and how our external environment affects the internal state—yes, even though your gut is inside your body, the inner section of the gut is actually part of the outside world!
The gut is home to a large amount of bacteria (there’s more bacteria than human cells)—most of which are good and without them we would become sick and die—and also to many, many cells of the immune system (these keep bacteria in check and make sure that what you eat is safe to the body). Motility is controlled by the gut’s nervous system, and digestion in turn is part of the parasympathetic nervous response (the resting and relaxing component). If any of this fine balance is compromised the cascade of events can be unfavourable. This article briefly outlines the connection between the brain and the gut, how it works and what happens when they fall out of balance.
What is the gut-brain connection?
The walls of your gut are in a way wrapped by an expansive network of nerve cells, which earned them the name of your “second brain”. This network is known as the enteric nervous system (ENS) is composed of over 100 million nerve cells (100 billion in the actual brain), and it goes from your esophagus to the rectum.
How it works?
Just like your brain cells respond to signals from its environment, the ENS has a bit of a similar role. Unlike your brain, the ENS cannot process “higher up” cognitive functions like memory or emotions—in other words, you cannot expect your gut to remember your partner’s birthday (not unless it’s your ex-partner and you no longer give…two tomatoes about it). However, the ENS helps in controlling digestive functions like swallowing, blood flow to the digestive tract for absorption of food particles, the release of digestive enzymes and reports back to the brain.
What happens if the connection is not optimal?
Because of the intimate connection between your nervous system and the digestive system, any stress (irritation, inflammation, etc.) will have an effect on the other. Take irritable bowel syndrome (IBS), for example. It is a syndrome because it encompasses several signs and symptoms, most of which are related to digestive issues (bloating, indigestion, diarrhea and/or constipation, thin stools, mucus in the stool) and anxiety (due to something provoking stress). It was previously believed that it was a one-way street, in which mental stress lead to functional issues in the gut. It is now known that the converse is true: irritation in the gut can also trigger mood changes! This includes anxiety, irritability and restlessness, but also depression, which is prominent in people with IBS.
Conditions that affect the normal flora (i.e. good gut bacteria) like improper use of antibiotics (even proper use of antibiotics will do this, but please note this is not negating the importance of proper use of antibiotics) will lead to the growth and retention of opportunistic bacteria that can produce toxins and elicit an inflammatory response. This can lead to abdominal pain, bloating, indigestion, diarrhea, and future intolerance to foods. These symptoms may be shared by other conditions that inhibit the proper movement of food through the gut (motility issues). Infections or conditions that affect the proper secretion of bile and digestive enzymes can and will lead to both gut as well as mood and behavioral changes.
What can be done to help?
There are so many new dietary fads and recommendations out there (e.g. gluten free), but that doesn’t mean they’re always effective or that they’re right for you. I recommend that you do your research. Speak with your team of health care providers, including a licensed naturopathic doctor on your options.
With that said, adhering to a clean diet that’s high in vegetables, moderate proteins and healthy fats would be a good start.
- Avoid processed foods.
- Avoid sugary drinks like juices and anything else that’s labeled “as healthy” vitamin-loaded drinks—they’re not loaded with any useful amount of vitamins, just sugars. Sugar can lead to inflammation in the gut, and can also be very bad to your liver (look up non-alcoholic fatty liver disease) and pancreas. Not all foods loaded in sugar need to be sweet.
- Always look at the nutritional labels and remember that under “Carbohydrates” each 4 grams of sugar equals a full teaspoon of sugar that you’re putting in your body! Eating in moderation means keeping that intake to under 19 g a day—and even that may be too much!
Probiotic: If you’re taking antibiotics, or just came off antibiotics, speak with your physician or naturopath about a good probiotic that would help replenish your gut. Not all probiotics are the same, nor are effective. The number of bacteria (or colony forming units, CFUs) matters; the variety of species matters; the quality of the probiotic (no additives) matters.
Some fermented products may be a good boost to ensuring that the probiotics thrive. Some sources claim that recolonizing the gut after antibiotic treatment may not be as easy as just taking a probiotic, so at least in theory, products that contain lactic acid may help to speed this process up a bit. This is because some of the probiotics are lactic acid producers, which helps with absorption of nutrients, but lactic acid also creates an environment bad bacteria don’t like. Finally, to help health the gut, there is some research that glucosamine and glutamine may be useful.
Stress relieving techniques and exercise can help bring down anxiety. This is because during times of stress digestion gets no priority from the brain. Our article on “How to deal with daily stressors” can help provide you with more information.