The conversation between your gut and brain is fascinating!
KEY POINTS
Your gut and brain are in constant communication
The health of your gut is strongly linked to your brain health
Your gut communicates with your brain through nutrients, microbiome products and other signals
Keeping your gut healthy with specific dietary strategies is a great way to prioritize brain health
Your Gut Brain Connection (part 1)
These days, it’s hard to talk about health without someone bringing up the importance of gut health. And now many of these conversations bring in the added idea of the “gut-brain” axis or connection. In fact, there is fascinating science that connects what happens in your gut with what happens in your brain –a conversation that also involves the gut microbiome. In this article (part 1 of a gut-brain series) we’ll define some key science and explore what it may mean for your health.
What is the gut exactly?
When people talk about “gut health,” what are they really referencing? Technically, the gut is a 30-foot-long tube that runs from your mouth to the end of your large intestine. Though it has a lot of important tasks, one of the most significant is that it converts the nutrients from your food into energy and building blocks for your body.
Every time you take a bite of food, this food is broken down by enzymes and physical processes in your gut that allow nutrients to be extracted and absorbed. These later become signals for your cells as well as the physical building blocks for your cells. In order to manage this complex task, the gut has a number of specialized cells tasked with breaking down, extracting and signaling the rest of the body about what you are eating. At the same time, the gut is tasked with keeping out microbes and toxins that could damage our health. It’s no surprise then, that poor gut health has been linked to a wide range of diseases, including brain conditions like Alzheimer’s, anxiety and depression.
What about the microbiome?
Technically speaking, the microbiome is the collection of all the microbes that live on and in us, along with all their genetic information. Most of the microbiome is located in the gut, although we have a microbiome on our skin, in our lungs and several other places on our bodies! Within the gut, the majority of our microbiome is concentrated in the large intestine, where there are trillions of bacteria living at this very moment.
How do the gut and the microbiome relate to our brain health?
1. The gut is the portal for building blocks for the brain
When our bodies absorb and break down food through the gut, this food turns into physical building blocks for our bodies. This is especially true as it relates to fats and proteins, but we also know that carbohydrates can play a role in the functional structure of our cells in something called the glycome (a mesmerizing new area of science I’ll cover in future posts). At a basic level, the food we eat and especially certain nutrients like B vitamins, magnesium and omega-3 fatty acids are key to a healthy brain by altering the structure and function of our brains. A healthy gut is necessary for optimal nutrient absorption, and the microbiome itself may help us to capture certain brain nutrients from our food that we’d otherwise have trouble absorbing.
2. The gut sends constant signals to the brain
Our gut, including the microbes that live in it, creates a wide range of signals, many of which reach and affect the brain. These signals can range from short-chain fatty acids (which are made by our microbes when we eat fiber) to immune signals (like inflammation) to hormones like ghrelin and leptin which alter our level of hunger. Signals from the gut can reach the brain by way of the bloodstream, or they can bind to and alter signaling from the vagus nerve which runs from the gut to the brain. Importantly, the signals from our gut to our brains can be helpful or harmful. Too much inflammation in our bloodstream from the gut, or bacterial toxins that enter our blood through a leaky gut may damage brain health, just as signals like SCFAs may benefit our brains.
How do we help maintain a healthy gut-brain connection?
There are a couple key steps that may help to promote a healthier link between our gut and brain and our health. In a future article, I’ll go deeper into additional strategies for gut-brain health and what to avoid, but here are two key steps to get the conversation started.
1. Eat more plants
I know this is a bold statement in an age where people are advocating for “carnivore” and other minimal plant diets. And while there are no universally perfect diets (and you should work with your health practitioner to find what’s best for you), the research seems pretty clear that for most people and most of the time, the gut likes us to eat plants. Why is this? Plants provide fiber, which turns into fuel for our gut microbiome. It provides other plant nutrients like polyphenols, which may have a beneficial effect on our bodies as well as our gut microbiome. As a basic tip, try including one colorful (green counts!) plant in every meal. Some especially notable gut-healthy foods may be dandelion greens, garlic, onions, leeks and bananas.
2. Consider eating some fermented food
Foods like kimchi, sauerkraut, yogurt, tempeh and pickled vegetables are called “fermented foods,” and generally contain live bacteria that may be good for our gut health. In the process of breaking down the carbohydrates in foods, the live bacteria may also generate a number of new molecules that may also benefit health. It’s also thought that fermentation may lower the levels of “anti-nutrients” in foods. For example, fermentation may decrease phytic acid in soybeans in the process of forming tempeh, and adding lactobacillus to sourdough led to a decrease in FODMAP content, which lowered IBS symptoms in people eating the fermented bread.
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