Trust Your Gut: The Gut-Brain Axis

= Gabi Kaplan, Laura Diamond, Jenni Diamond, OT Reg. (Ont.), & Evan Cole Lewis, MD =


What is the Gut-Brain Axis?

Have you ever wondered why we use the expressions “gut-feeling” or “butterflies in your stomach?” These phrases stem from the connection between our gut health and brain function. This connection is called the Gut-Brain Axis, which is a bi-directional communication network that links the central nervous system (the brain and spinal cord) with the enteric nervous system (the digestive system) (1). Your brain and digestive system send messages to each other and can affect one another’s health and functioning.

Disturbances to the gut-brain axis may be  associated with many neurological conditions, some of which include anxiety, depression, autism spectrum disorder, Alzheimer’s disease, and Parkinson’s disease (1).


What happens to our gut when there is trauma to our brain?

People who have experienced a traumatic brain injury (TBI) may undergo a disruption to the gut-brain axis and gastrointestinal (GI) changes. TBI can induce both structural and functional changes to the gut including (2):


People who have experienced a traumatic brain injury (TBI) may undergo a disruption to the gut-brain axis and gastrointestinal (GI) changes.


Can targeting our gut assist in brain injury recovery?

Current research is exploring the possibility that interventions targeting our gut may assist in brain injury recovery and improve cognitive function. Some interventions that are currently being assessed  include (1):


As more research is done, gut-brain axis interventions may indeed pose as a therapy option for brain injury recovery.


As more research is done, gut-brain axis interventions may indeed pose as a therapy option for brain injury recovery. And the next time that you have butterflies in your stomach, take care of your gut and you will be taking care of your brain!



  1. Zhu, C. S., Grandhi, R., Patterson, T. T., & Nicholson, S. E. (2018). A Review of Traumatic Brain Injury and the Gut Microbiome : Insights into Novel Mechanisms of Secondary Brain Injury and Promising Targets for Neuroprotection, 8(6).
  2. Sundman, M. H., Chen, N., Subbian, V., & Chou, Y. (2017). Brain , Behavior , and Immunity The bidirectional gut-brain-microbiota axis as a potential nexus between traumatic brain injury , inflammation , and disease. Brain Behavior and Immunity66, 31–44.

Concussion and Cannabis: Could CBD be used following brain injury?

= Authors =

Laura Diamond, MSc Global Health Student

Gabi Kaplan, Student Occupational Therapist

Jenni Diamond, OT Reg. (Ont.)

Evan Cole Lewis, MD

April 9, 2019


The therapeutic benefits of cannabis

Cannabidiol (CBD) is one of over 100 cannabinoid compounds found in the cannabis plant. CBD has been shown to have many potential therapeutic benefits, including neuroprotective effects (1). Results of clinical studies support its use in some conditions associated with difficult to treat epilepsy and for symptoms related to multiple sclerosis (2,3,4,5). There is emerging support for its use in other areas such as chronic pain, anxiety, and Parkinson Disease to name a few (6). Currently, however, little is known about the role of cannabis in treating concussions and post-concussion syndrome.


Cannabis and concussion: What we know so far…

Majority of the existing research on CBD and concussion has been limited to animals. Most notably, a 2012 study on rats revealed that administration of CBD after brain injury had long-lasting, positive effects on the brain, including reducing the severity of the injury and restoring overall neurological function (1).


… medicinal cannabis may pose as an option for treating concussion-related chronic pain, specifically headaches.


More recently, however, this research has been shifting toward humans. A 2018 study reviewed previous hospital charts and displayed that medicinal cannabis may pose as an option for treating concussion-related chronic pain, specifically headaches (7). However, these novel findings are quite preliminary and more studies are needed to validate the results.


The future of cannabis-concussion research

Recently, many researchers have been interested in advancing these emergent findings and investigating this alternative concussion intervention. In fact, Dr. Gillian Hotz is currently embarking on an ongoing study investigating the effects of CBD in combination with an anesthetic for individuals with traumatic brain injury. Her preliminary findings suggest that this treatment improves cognitive function in mice (8).

In addition, one of the first double-blind studies exploring the effects of cannabis and concussion is expected to be conducted this summer by NEEKA Health Canada, the NHL Alumni Association and Canopy Growth Corporation, a cannabis company. This exciting new study will explore the efficacy of cannabis on reducing post-concussion syndrome impairments, such as depression, PTSD, and progressive dementia, among 100 previous NHL players.

The possibility of CBD as an effective intervention for post-concussion syndrome is without a doubt exciting! Stay tuned for future studies in this emerging field, and for the results of this upcoming study on professional hockey players.


If you or a loved one are suffering from a concussion, be sure to speak to your physician or contact NCT  to discuss which treatment options are best for you.




  1. Pazos, M. R., Cinquina, V., Gómez, A., Layunta, R., Santos, M., Fernández-Ruiz, J., & Martínez-Orgado, J. (2012). Cannabidiol administration after hypoxia–ischemia to newborn rats reduces long-term brain injury and restores neurobehavioral function. Neuropharmacology,63(5), 776-783.
  2. Davies, S. (2018). Cannabis Scheduling Review Part 1: The therapeutic and medicinal benefits of Cannabis based products–a review of recent evidence. London: Department of Health and Social Care.
  3. Devinsky O, Patel AD, Cross JH, et al. Effect of Cannabidiol on Drop Seizures in the Lennox–Gastaut Syndrome. N Engl J Med 2018;378:1888–97. doi:10.1056/NEJMoa1714631
  4. Friedman, D., & Devinsky, O. (2015). Cannabinoids in the treatment of epilepsy. The New England Journal of Medicine, 373(11), 1048-1058.
  5. McCoy B, Wang L, Zak M, et al. A prospective open-label trial of a CBD/THC cannabis oil in dravet syndrome. Annals of Clinical and Translational Neurology 2018;5:1077–88. doi:10.1002/acn3.621
  6. Russo, EB. (2018). Cannabis Therapeutics and the Future of Neurology Front. Integr. Neurosci.
  7. McVige, J., Bargnes, V. H., Shukri, S., & Mechtler, L. (2018). Cannabis, concussion, and chronic pain. Neurology, 91(AAN Sports Concussion Conference, Indianapolis, December 04, 2018: Vol. 91, Issue 23 Supplement 2).
  8. Lief, E. (2018). Work Continues On A Pill To Treat Concussions. Retrieved from

The Confusing Science of Wandering Minds, Focused Attention, and Well-Being

An interesting study out of Harvard confirmed last year that “a wandering mind is an unhappy mind.” But, what about the evidence suggesting that letting the mind wander can actually be helpful for concentration and memory. What do these seemingly conflicting findings mean for your Mindfulness meditation practice?

You’ve probably heard people talk about the importance of staying present in the moment. Well, an interesting new study out of Harvard confirmed last that “a wandering mind is an unhappy mind.” That should provide further motivation to use meditation to stay present. But, judging from some of the other recent news from the science of human attention, the story is a little more complex than that. Take for instance, some of the compelling evidence that letting the mind wander can actually be helpful for concentration and memory. What do these seemingly conflicting findings mean for your Mindfulness meditation practice? Let’s see.

The study by Matthew Killingsworth and Daniel Gilbert at Harvard University just came out in the Science – perhaps the most prestigious scientific journal in the world. The researchers used smart phones to ask 2,250 participants, at random times, what they were doing at that moment, and whether they were thinking about their current activity or about something else that was pleasant, neutral or unpleasant. Amazingly, on average, people reported that their mind was wandering about 47% of the time and no less than 30% of the time during all activities (except sex!). People were happiest when making love, exercising, or engaging in conversation. They were least happy when resting, working or using a home computer. However, it turns out that what you think about is more important than what you are doing. “How often our minds leave the present and where they tend to go is a better predictor of our happiness than the activities in which we are engaged,” Killingsworth says. The authors go on to suggest that “the ability to think about what is not happening is a cognitive achievement that comes at an emotional cost.” They conclude the paper by saying that “many philosophical and religious traditions teach that happiness is to be found by living in the moment, and practitioners are trained to resist mind wandering and to be here now. These traditions suggest that a wandering mind is an unhappy mind.”

Now consider a different line of research suggesting that mind wandering is actually a good thing. Eric Klinger from the University of Minnesota argues that the ability to think about things other than the unbearable present (stuck in traffic?) is an asset because it “serves as a kind of reminder mechanism, thereby increasing the likelihood that the other goal pursuits will remain intact and not get lost in the shuffle of pursuing many goals.” (Incidentally, I think this is why many people in my Mindfulness groups prefer not to do their Mindful eating meditation over lunch; they tend to rely on this break as a time to loosen their thinking and check back in with the big picture.)

Apparently, this state of “Mindwanderness” (Mindfulness’ ugly cousin?) is actually the default setting of the brain’s attention circuits. When we want to concentrate on something for a sustained period, the executive network of the brain (part of the frontal lobes) has to inhibit this default circuit and actively keep us on task. But this is a demanding process, so we tend to zone out easily and often – some estimate 10% of the time, I suspect it’s more – and rely on meta-awareness to bring ourselves back on task. Unfortunately, we have a limited amount of mental resources to sustain that kind of directed attention, according to University of Michigan brain scientist Marc Berman. In short, we get tired. In that sense, the frontal executive network is not that different from a muscle that gets tired after a workout. You need to take breaks and recover before you can use the muscle effectively again.

That line of thinking is at the heart of an exciting new movement in education, which pushes for children to spend more of their school time outdoors, in nature. Marc Berman argues that nature offers “soft fascination,” in that natural stimuli spontaneously call our attention, without overwhelming us (think waves on the water, a fluttering butterly, or leaves rustling in the wind). This means that the brain’s other attention network – the one that supports effortful, directed attention – gets to rest. According to Berman’s attention restoration theory: “Urban settings aren’t as restful because they require more vigilance to avoid cars, buses or other hazards. Television, movies and computer games may be too absorbing to allow the circuitry involved in paying attention to recharge.” So far, the data have provided clear support for “attention restoration theory:” students that spend time in nature consistently score better on attention and memory tasks (and may even be more creative). Research us currently under way to understand how much nature is needed and how all of this plays out in the brain.

So what are the implications for Mindfulness practice? Is it time to give Mindwanderness another chance? Well, that depends on what you mean by Mindfulness. Many beginners tend to think that Mindfulness involves having a completely clear and relaxed mind; that with practice and discipline, they will get better at suppressing distraction and staying focused. While it’s true that Mindfulness can help cultivate better focus, it is about more than that. It is about being awake in life – being aware of the impact the quality of our attention has on our experience. The study by Killingsworth and Gilbert supports the ancient principle that attention in the present moment is a key to happiness. Our ability to think about things other than the present means that we can waste all kinds of time ruminating on the past or worrying about the future. Meanwhile, life is passing us by. But staying present in the moment doesn’t necessarily mean keeping a sustained, narrow focus on one object of attention. Letting our attention be guided by the flow of stimuli in nature – what Mindfulness people called “choiceless awareness” – is another excellent way to be present in the moment. In fact, the research reviewed here suggests that cultivating that choiceless awareness may actually help us to concentrate and remember things at work later in the day. Ultimately, the practice of Mindfulness helps you become more aware of how you are paying attention right now. From there, it’s up to you to decide what to do about it. Do I still have enough mental juice to finish reading that memo? Or is it time to take a break and let the mind wander for a bit? Either way, you’re awake and aware of the options so that you can make optimal decisions for yourself. I’m feeling pretty drained at the moment, so it’s time for me to go for a run on the mountain.