We often say "Trust your Gut" as though our gastrointestinal system has some sort of divine intelligence. Turns out, that's not entirely wrong.
Yesterday I had a baked spinach and artichoke dip with some crackers. It was so tasty that I may have just a little more than necessary. But then 15 minutes later I completely forgot about the meal. Life had moved on-but only for one of my brains. For the other brain, that meal would become the focus of the next several hours-maybe even days-as the food is slowly digested and the relevant nutrients absorbed. This other brain is called the Enteric Nervous System (ENS), which is separate from the Central Nervous System (CNS) that you probably think of when a brain comes to mind. We think that our CNS brain is smart because it controls our thoughts, feelings, and actions, in addition to indirectly regulating the rest of the organ systems in our body. Our lungs and heart dynamically change how they function based on information that the CNS brain sends out through nerves and hormones. The same thing is true for digestion, only this process is super complicated, so the gastrointestinal system (GI tract) has its own mini-brain, the ENS, to deal with all of this complexity.
A great way to think about your GI tract is like a chef cooking dinner-only in reverse. Raw food contains a lot of energy, but it's in an unusable form, so it needs to be cooked into a form that is useable. Our GI tract takes prepared food and deconstructs it: prepared food enters our mouth and begins breaking down our food into its component parts. And like how an effective chef can juggle multiple different cooking processes to ensure every dish is ready on time, the GI tract juggles multiple digestion processes to extract energy and nutrients from food. Now imagine comparing someone making dinner alone to a large-scale catering event feeding dozens of thousands of people. That's one way to think about how much more complex our ENS's job is compared to even the world's best chef (#SorryRamsey). The ENS has the difficult task of figuring out what we have all eaten and coordinating all of the various digestive processes along our GI tract. This puts some "big data analytics" projects to shame by comparison of complexity.
If that didn't seem complicated enough, our ENS has to function not only like the world's biggest food preparation and distribution service, but also as a diplomatic military force. When we eat food, we also ingest all of the microorganisms that our food is covered in. Since birth, your ENS has been building a relationship with the microbes inside of your GI tract and working with the immune system to eliminate the harmful microbes. This creates a very strong link between the inflammation signalling of the immune system and the digestion functions of the GI tract1. Part 2 of this blog will explore how this inflammation can impact brain health. For now, let's take a deeper dive into the relationship between inflammation, the ENS and the microbiome.
It's a gross over-simplification to say that all inflammation is bad2, but chronically high inflammation can contribute to many different diseases, including depression3, pain4, and cancer5. The GI tract is no exception, as research from Dr. Keith Sharkey at the University of Calgary suggests that inflammation can cause complex and long-lasting changes to the ENS6. This in turn causes disruption for the GI tracts ability to properly digest food and could lead to diseases such as Irritable Bowel Syndrome and Colitis. Thankfully, the ENS can get some help through the relationship it has built with the microbiome. For example, in one of Dr. Sharkey's studies, they fed rats a high sugar and high-fat diet to put them at risk for obesity and found that adding a pre-biotic was able to reduce the effects of obesity through changes in the microbiome7. This highlights the crucial role for our diet to not only include the nutrients our body needs but also nutrients to take care of our microbiome as well.
The research on the complex emerging relationship between nutrition, gut health, and brain health was the inspiration behind Foothills Picnic by Neil Dawson. Dr. Sharkey's research is just scratching the surface of understanding how different components of our diet can help promote whole-body health and wellness. The artichokes featured in the foreground of the painting are known to have pre-biotic properties8, making them a great food for building a healthy microbiome and aiding in digestion. As we learn more about the ENS, the microbiome and their huge influence on inflammation, the role of nutrition is becoming increasingly recognized as a key therapeutic tool in combating many different kinds of disease. Check out Part 2 for more details on emerging research that could lead to dietary interventions for neurological conditions, like Multiple Sclerosis and Stroke. Now that we have an appreciation of the amazing job our ENS does at the complex task of digestion, it really bring a new meaning to having faith in your gut response since its a smart cookie!
Foothills Picnic can be viewed as part of the Your Brain On Art exhibit of Calgary's Chinook Blast.
The painting will be auctioned off as part of the virtual Your Brain On Art March 11 virtual gala to fund more innovative brain health research on topics like the ENS and the microbiome. .
Check out the other incredible neuroscience-inspired art pieces featured in the YBOA gala (March 11, 6:00-8:00PM MST) and get your tickets before they run out! .
Scientist + Artist = Impact
Your Brain on Art is a collaboration where world-class neuroscientists inspire artists to use their creative talents to raise awareness for brain health research.
Dr. Keith Sharkey
...about NeuroCAM and inflammation
...about a walking intervention for MS
...about how Trauma impacts the Hippocampus
1. Nasser, Y., Keenan, C. M., Ma, A. C., McCafferty, D. M., & Sharkey, K. A. (2007). Expression of a functional metabotropic glutamate receptor 5 on enteric glia is altered in states of inflammation. Glia, 55(8), 859-872.
2. Fraunberger, E., & Esser, M. J. (2019). Neuro-Inflammation in Pediatric Traumatic Brain Injury—From Mechanisms to Inflammatory Networks. Brain sciences, 9(11), 319.
3. Strawbridge, R., Arnone, D., Danese, A., Papadopoulos, A., Vives, A. H., & Cleare, A. J. (2015). Inflammation and clinical response to treatment in depression: a meta-analysis. European Neuropsychopharmacology, 25(10), 1532-1543.
4. Parkitny, L., McAuley, J. H., Di Pietro, F., Stanton, T. R., O’Connell, N. E., Marinus, J., ... & Moseley, G. L. (2013). Inflammation in complex regional pain syndrome: a systematic review and meta-analysis. Neurology, 80(1), 106-117.
5. Yang, R., Chang, Q., Meng, X., Gao, N., & Wang, W. (2018). Prognostic value of systemic immune-inflammation index in cancer: a meta-analysis. Journal of Cancer, 9(18), 3295.
6. Lomax, A. E., Fernandez, E., & Sharkey, K. A. (2005). Plasticity of the enteric nervous system during intestinal inflammation. Neurogastroenterology & Motility, 17(1), 4-15.
7. Cluny, N. L., Eller, L. K., Keenan, C. M., Reimer, R. A., & Sharkey, K. A. (2015). Interactive effects of oligofructose and obesity predisposition on gut hormones and microbiota in diet‐induced obese rats. Obesity, 23(4), 769-778.
8. Ramnani, P., Gaudier, E., Bingham, M., van Bruggen, P., Tuohy, K. M., & Gibson, G. R. (2010). Prebiotic effect of fruit and vegetable shots containing Jerusalem artichoke inulin: a human intervention study. British journal of nutrition, 104(2), 233-240.