How Your Gut & Your Brain Interact - And Why You Should Care

Find out more about why the gut has been referred to as the "second brain" and how it can influence your body's reactions, your moods, and more.

1 in 3 people suffer from bloating on a regular basis and yet, many of them don’t do anything about it. How come? The gut is currently the most underrated and neglected organ in our body. We carefully and meticulously work to take care of our skin, heart, lungs, kidneys, brain, and so on, but it wasn’t until very recently that anyone started really wondering what was going on with the gut, beyond the fact that it was helping us get food in and out.

Beyond its digestive functions, the gut is actually a key organ in the human body and it is often described as a “second brain” in your body by communicating with all its neighbors (heart, lungs, stomach, and so on) and reporting on everything back to the brain, which is cozily isolated in your skull. This communication pathway is called the gut-brain axis, and while research from the past decade have reported on its importance in maintaining our overall health, scientists and researchers continue to study it and learn more every day. Based on current evidence though, the gut-brain axis has linked gut-activity to mood, our nervous system, and even our sleep! 

The gut and the brain communicate - all the time.

You can think of the gut and the brain working together as a team to maintain and protect your health. They do as much for basic functions (e.g knowing when and what to eat) as well as in extreme circumstances. For example, in cases of exceptionally high stress and anguish or sadness, the gut will allocate as much energy as possible to the brain. To do so, it typically depletes itself of food to have more energy for its partner, which can result in stress vomiting. 

This type of interaction has resulted in some doctors describing stress as ‘unhygienic.’ This is because while the gut is sharing a significant portion of its energy with the brain, there is less energy left in the gut itself to monitor what types of bacteria are allowed to grow there. As a result, different bacteria - not necessarily good ones - are being allowed to survive in the gut during moments or periods of high stress.

The gut, however, seems to be able to do much more than simply respond to the demands of the brain. One experiment conducted in 2011 - when the idea of playing with the gut to alter behavior was relatively new - showed that a group of mice was able to swim longer, contained less blood stressors, and performed better in memory and learning tests after they were fed Lactobacillus rhamnosus, a bacteria known to be good for the gut (which is one of the probiotic strains included in Daily Digestive Essentials). 

Your gut is affecting your nervous system - and vice versa.

A healthy microbiome helps build a healthy brain. When you were a child and collected baseball cards or My Little Ponies, your body was collecting bacterial species that helped build your immunity and further your neurodevelopment. Which, if you ask us, retains its value far better than, say, Beanie Babies.

You probably remember from those high school science classes that your nervous system sends signs through electrical impulses that help your brain interpret its environment. But the bacteria living in your gut also send messages to the brain through the central nervous system (CNS). Indeed, the gut has been known to be sensitive to emotions and you’re probably familiar with expressions such as having “butterflies in your stomach” or being “gut-wrenched.” There is no denying that the gut and the brain are intimately linked. For example, the simple thought of eating releases juices in your stomach before you’ve had your first bite!

Although researchers are still teasing apart the complicated relationship between the gut and the brain, they’ve found connections between your gut bacteria and anxiety, stress, and depression. Conditions ranging from prenatal stress, to a high-fat diet, to maternal immune responses can all affect the CNS by changing the delicate composition of bacteria in the body. But more work needs to be done to tease apart the details of these connections.

What about mood?

The news cycle and your new job have a heavy effect on your mood, of course, but so does your gut health... Researchers are digging deeper into the gut-brain axis, or the intricate connection between your gut health and mental health and a lot of this seems to come down to serotonin — a neurotransmitter that communicates moods like happiness and sadness. Serotonin does more than just control mood, however, and in fact impacts every part of our body and helps with every key function including sleeping, eating, and digesting. 

Serotonin is also famous for being linked disorders such as anxiety and depression, when it is found in very low levels. That’s why selective-serotonin reuptake inhibitors, SSRIs for short, are commonly used to treat many of these psychological conditions.. SSRIs work to combat anxiety, depression and other mental illnesses by increasing overall levels of this “happy hormone” in the body. 

So how are the gut and depression or the gut and anxiety linked? A vast majority (a whopping 90%, for the record) of your body’s serotonin is produced in your gut! But this isn’t necessarily something genetic over which you have no control. Researchers in an emerging field called nutritional psychiatry suggest that the gut microbiome and mental health are connected, and that a healthy diet should be seen as one part of a robust treatment plan for conditions like depression and anxiety. 

Specifically, these researchers are examining how the foods we eat contribute to mental health by supplying different strains of bacteria with the nutrients they need to flourish. What they’ve found is that ultra processed foods, especially those with chemical additives, alter the gut environment, leading to inflammation and, potentially, disease. While diet should never be the only component of treatment, eating a diet rich in whole, unprocessed foods may help alleviate depression. In fact, a healthy dietary foundation can help improve your mood across the board. 

Could long-term brain health be influenced by your gut?

Degenerative brain diseases like Alzheimer’s dementia and Parkinson’s disease are devastating for the patients and their families. One of the hardest parts of these illnesses, is that there’s still so much we don’t know about them, especially concerning how and why certain people get them and not others. While research like that of Barbara Bendlin, PhD, and Frederico Rey, PhD at the Wisconsin Alzheimer’s Disease Research Center, who are looking  into gut health and how it affects the entire body, offer some hope of shining a new light on these conditions, there is still much to do.

As we deepen our understanding of the microbiome over the past decades, we’ve also deepened our understanding of degenerative brain diseases. In certain contexts, scientists have found that gut dysbiosis — an imbalance of good and bad bacteria — may explain how some of these diseases develop. For example, studying the microbiomes of patients with Alzheimer’s revealed differences in the diversity of their gut bacteria. Specifically, patients with Alzheimer’s suffered from low levels of Bifidobacterium, an important strain of bacteria found in the healthy gut. Bacteria levels were also linked to the severity of the disease, which was measured by the number of proteins found in patients’ spinal fluid. Altogether, these findings hint that restoring a healthy balance in the gut microbiome of high-risk populations may decrease these people’s chances of later developing Alzheimer’s.

Another brain disease affected by gut health may be Parkinson’s disease — especially for people with the SNCA gene, a known risk factor for Parkinson’s. In patients with this genotype, higher levels of the species Corynebacterium may contribute to Parkinson’s. Good gut bugs may predict why some patients with this gene develop Parkinson’s, while others do not. There’s still a lot we don’t know, but researchers see exploring the gut as a promising path forward.

How to take care of your gut

The gut is a fascinating organ whose role inside the human body we’re learning more about every day. What we do know is that better overall health begins with better gut + digestive health. At rmdy, our mission is to research, curate, and simplify the best ingredients and information so that you can take better control of your health- from the inside out. We partnered with leading doctors and researchers to identify and thoughtfully address the gaps in our digestive health in a comprehensive approach. The result? Daily Digestive Essentials: a research-backed blend of pre & probiotics, digestive enzymes, and herbal ingredients to prevent gas & bloating caused by everyday foods and to strengthen your gut health. Learn more about the importance of gut health here.