We’re all familiar with that rush of deep pleasure we feel when something decadent slides across our taste buds. Chocolate. Rich cheese. A moist slice of cake. A salty handful of our favorite snack.
In other words, we’ve all had the experience of a moment of euphoria after eating something indulgent. Aside from the obvious great taste, science explains this as happening due to the release of feel-good hormones, namely serotonin, that results from certain flavor and macronutrient combinations.
However, the link between our mood, gut, and the foods we eat goes much, much deeper than these simple pleasure hormones. In fact, your gut health could be influencing your mood over the long term, and unless you’re aware of the gut-brain connection, you may believe moodiness and even mood disorders are “all in your head.”
Here, we go over why that may be true … but also why your second head could be playing a much larger role in your mood than you know.
How Your Gut Acts As A Second Brain
Now, when we say your gut is your “second brain,” we don’t mean it’s down there making mathematical calculations, pondering its existence, or writing poetry - those are functions unique to your brain. However, this doesn’t mean that your gut isn’t having a significant effect on your nervous system, which is directly linked to your brain … and consequently, your emotions and mood.
To illustrate how this is possible, let’s first debunk the idea that your gut is made up of nothing more than a network of intestines, undigested food, and bacteria. In reality, it contains a sheath of roughly 100 million neurons (more than either your spinal cord or peripheral nervous system!) referred to as your enteric nervous system (ENS), and runs along the walls of your gut from top to bottom. It contains the largest number of neurons outside of your brain, hence the nickname.
Interestingly, the ENS also contains virtually every neurotransmitter found in our central nervous system (CNS), which is the main control seat of our brain and spinal cord, thoughts, interpretations from our environment, and even our physical movements. This means that, essentially, our gut is capable of communicating with our bodies using the same neurotransmitters as those found in our mind’s “control center,” creating a profound link between the two.
Within this network also lies the vagus nerve, a large cranial nerve that scientists have found uses 90 percent of its fibers to carry information to the brain from your gut, not the other way around. This is one of the reasons why some successful treatments for depression involve stimulating the vagus nerve in certain ways, since this can theoretically cause different neurotransmitters and signals to be released and sent to the brain, altering mood.
Other research illustrates this, showing that stimulating the vagus nerve can be helpful in treating post-traumatic stress disorder and anxiety disorders.
As if that weren’t enough to make you question who’s really running the show, scientists have also found that the bacteria in our guts (good or bad) interact directly with our enteric nervous system, which can result in their own messages being relayed to your brain. Again, this is another reason why we see studies that show participants’ moods improve when supplementing with probiotics, or good bacteria.
How Your Gut Health (And The Foods You Eat) Affect Your Mood
So what does all of this mean on a day-to-day level? If we consider the study mentioned above where participants who supplemented with probiotics had an improvement in their mood due to the interaction of bacteria with their ENS, we can take actionable steps to possibly improve our own mood by supplementing with probiotics and consuming more fermented foods, like sauerkraut, non-dairy yogurt, and kimchi. And this is just one avenue.
Once we understand that the ENS and vagus nerve are constantly sending neurotransmitters as signals back to our brain, we can easily see why what we eat and the health of the gut sending those signals is so important.
The role food plays in this delicate interaction between our ENS and brain is a pretty big one. If you’re eating, frankly, a terrible diet filled with processed foods that are harming your gut by creating inflammation, or by feeding bad bacteria, you may be setting yourself up for a bad mood, or even depression. This is because the signal your brain is getting from a hurting, unhealthy gut is very different from that of a healthy, well-functioning gut.
We can see this in studies on individuals who have lactose malabsorption: those who were unable to digest lactose and experienced bloating, cramping, diarrhea, etc … also experienced higher rates of depression.
Eating processed, high-sugar foods can also lead to bad bacteria overgrowth, which is bad news for serotonin, the feel-good hormone that helps stave off depression. 95% of serotonin is manufactured by the good bugs in our gut, so if we don’t have very many of them, we may be unable to properly produce a crucial mood-balancing neurotransmitter.
Improving Your Mood By Improving Your Gut
Now that we know moods and possibly many mental disorders have roots not only in the brain, but in the gut as well, we can begin to work on the health of our guts to improve the health of our moods and mental state.
One of the first steps you should take in clearing up your gut health is to clear out the processed foods and excess sugars. Yep, that means getting rid of most boxed and pre-prepared meals and ingredients in favor of whole, natural foods.
The next step would be to either do an elimination diet by eliminating dairy or other suspect foods like eggs and gluten from your diet and noting how you feel. Do these one at a time so you don’t have to wonder which one had the effect. Another option with this is to get a food sensitivity test done to rule out any odd food sensitivities (for instance, some people are sensitive to nightshades like tomatoes), which is key if you’ve been experiencing digestive issues from seemingly unknown causes.
Dropping all sugar and adding in probiotics is a wonderful, immediate start to improved gut health as well. We’d recommend a high-dose probiotic of at least 50 billion strains to start with, as well as adding in sauerkraut, kimchi, and non-dairy, unsweetened yogurt.
Once you eliminate foods and start adding them back in, you’ll start to notice those that make you feel “off.” Try not to judge this feeling just because a food is “healthy”; some people don’t feel well after eating mushrooms, regardless of how healthy they are considered a health food. Consider also keeping a mood-food journal, noting your mood after consuming certain foods and meals.
While the interplay between our gut, food, and mood is intricate, it’s also extremely valuable information to be aware of, especially if you’re suffering from mood issues. “We are what we eat” just became a more realistic statement than we ever thought possible.