It’s estimated that almost 20 million adults in the United States have experienced depression at some point in their life. 1 Although feeling sadness and grief are normal human emotions, experiencing depression can be a life-threatening disorder - including putting your own life at risk. It can feel like living in a tower of solitude, isolated by an overwhelming ocean in a storm with no end in sight. For families, having a loved one suffering from this disease can feel like drowning, without hope in sight for what seems like an impenetrable condition. The economic burden associated with depression each year costs America over 210 billion dollars. 2 That includes lost income at work, to the cost of medication, down to the costs associated with hospital visits. Ultimately, the greatest cost of mental health disorders are the number of lives that are taken each year, too soon.
Many who suffer from this condition find it impossible to do normal tasks, often exhausting their only energy just to finish the day. This is a truth that is all too common and can affect anyone at any time. Despite the prevalence of mental conditions like depression, the cause of these mood disorders is not well understood. Many neuroscientists have sorted out what exactly is occurring in the brain, but why it’s happening has proven elusive. With the budding knowledge of the gut-brain axis, neuroscientists are finding that the connection between our gut microbiome and our mental health may be more interlinked than we thought - which shouldn’t be so surprising. The more we learn about the individualized activity of each person’s gut microbiome, the more Viome understands how personalized nutrition could be used as therapy one day to cure and prevent disease.
A Short Intro Into Brain Function
As you can imagine, the brain is the most complex organ in the human body, containing over 100 billion neurons connecting and sending chemical messages that control just about every process in our body. 3 To work properly, these neurons must work perfectly in sync with each other and maintaining their cellular health means operations can continue to run smoothly.
The best way they can achieve this communication is by releasing certain chemical messengers called neurotransmitters – like dopamine, epinephrine, and serotonin – between neurons at what is called the synaptic cleft. Think of two electrical wires, a positive and a negative, that emit a spark of electricity when connected. This electrical current is not unlike what occurs in our brain. In fact, our brain actually produces its own electricity!
During these “sparks,” a flood of neurotransmitters is transferred from the end of one neuron to the next. 4 When an imbalance of these chemical messengers occurs (as in a flood, or a trickle, where there should be a steady stream), the message being sent can get jumbled or faded. This imbalance can have severe consequences with our mood and mental health, making us feel overwhelmed and depressed. When our neurons get less than the expected level of neurotransmitters, they begin to degrade and we end up with unhealthy, dying brain cells. When this happens, it makes the symptoms of depression much worse, heightening the level of chemical imbalance within our brain. 5 This is another reason why depression medications also try to increase the level of available neurotransmitters, however, they fail to fix the problem and create only a temporary relief.
Imbalance of the Brain, An Imbalance of the Gut Microbiome
Scientists have had many theories as to why this imbalance occurs, including lapses in communications between different structures in the brain. However, it has proven a little more difficult than expected to pinpoint.
If you or someone you love has suffered from depression, it can be pretty clear it doesn’t just affect our brain. There are many other real symptoms associated with mood disorders, such as chronic pain and upset GI. When it comes to the gut, depression patients often suffer from appetite disturbances, metabolic changes, gastrointestinal disorders, and odd changes in their gut microbiome. 6 In general, you can view major depression as not just a simple mental disorder, but a systemic disease.
Once scientists began looking at depression through this view, they started to compare symptoms and noticed a trend – there were a lot of patients that suffered these gastrointestinal issues. Could it be that the changes in the gut were influencing the brain?
Which brings us back to the gut-brain axis.
Our Second Brain
Our actual brain controls most of the functions in our body by sending direct messages via our central nervous system (CNS) to many of our organs and limbs. 7 The CNS is made of an intricate system of nerves that travel down our spine and branch out through our entire body. Feel that paper cut? That’s the CNS. Foot fall asleep? That’s the CNS. See that bird? That’s the CNS sending messages through your ocular nerves to your brain.
But your gut has a mind of its own, made of up of its very own nervous system called the enteric nervous system (ENS). 8 Scientists often refer to this as our “second brain.” This system is in constant communication with our CNS, sending messages back and forth like your favorite childhood set of walkie-talkies (I’m, of course, talking about the two plastic cups connected by a random string found in a once-forgotten craft drawer). Many of these conversations consist of cognitive and emotional messages being transmitted back and forth. That’s why when you’ve misplaced your wallet or your keys, you might feel a sense of anxiety that branches straight down into your gut. It’s also why many detectives refer to their “gut feeling” when they have a hunch about something.
This cross-talk is typically what we refer to as the gut-brain axis : and it has close ties with your gut microbes.
We know that our gut microbes are very active creatures that work to make their ecosystem ( you) stable and comfortable. Scientists have mounting evidence that microbial activity can affect our hormone signaling, alter our intestinal permeability (i.e. cause leaky gut syndrome), produce many metabolites helpful – or harmful – to our body, and affect our immune system. 9 In fact, our immune system is essentially housed in our gut. You could even imagine your digestive tract as an immune organ.
Direct changes in gut health, like microbiota abnormalities, can influence our behavior [and vice versa, as well], and cause changes in our mood.
Gut Dysbiosis: The Trigger of Systemic Inflammation
When we experience a wave of inflammation in our gut, most health specialists immediately think of one thing: gut dysbiosis. Gut dysbiosis has been shown to produce a significant immune response, causing high levels of inflammation that often overflow into other areas of the body.
Despite the fact that most of our gut microbes work in sync to stabilize and balance their gut ecosystem, issues of imbalance can occur. Just like in depression, the imbalance of activity can result in a change that affects our health - in this case by allowing beneficial bacteria to be taken over by pathogenic or “opportunistic” bacteria (the ones that play quietly on the sidelines until the main players gets hurt. When their time to shine comes up, they often mess up the whole play). This creates an imbalance among our gut microbiome, termed gut dysbiosis, which doesn’t translate well for the whole system and can result in harmful bacteria running rampant. They can even disrupt the activity of beneficial microbes that have genes that help regulate neurotransmitter activity. Moreover, gut dysbiosis has been shown to produce a daunting level of inflammation from our immune system, surpassing the boundaries of our digestive tract.
As inflammation levels reach the central nervous system, they can interfere with signals being sent to the brain and induce psychological distress. 10 Reducing the inflammation being produced in the gut can improve its hold over our CNS, all by stabilizing your gut ecosystem. Many scientists believe this may be what’s happening in those who suffer from depression. Their gut microbiome showed imbalance, and the diversity of the microbes present was harmed. 11
To determine if gut microbes were actually causing these symptoms, some studies using mice with a sterile gut found a fecal transplant from humans with depression caused depressive behavior in mice. 12 These patients with symptoms of depression were found to have less biodiversity in the gut microbiome and suffer from gut dysbiosis. In patients taking antibiotics – which can harm many microbial populations and not just the pathogenic bacteria - symptoms of depression were more prevalent, further heightening the evidence of how gut dysbiosis influences neurological conditions. 13
Thus, focusing on methods to recalibrate and bring back diversity and balance to the gut have been helpful targets for the treatment of mood conditions. Scientists have found that four main methods have shown promise as therapies. Studies examining gut strategies and symptoms of depression have found that in some cases 1.) probiotics, 2.) prebiotics, 3.) a healthy diet, and 4.) fecal microbiota transplantation (FMT) have been effective, though these studies fail to integrate a comprehensive approach that includes individualized analysis over time. With Viome, you receive an in-depth analysis that examines you as a whole to provide personalized recommendations to improve your overall health. As you retest, you can see the changes in your gut microbiome that has been influenced by the nutrition plan we provide for you to follow.
Viome: Personalized Nutrition Recommendations for Your Gut Microbiome
If dysbiosis in your gut is caused by poor diet, enacting a change in diet with foods specific to your gut’s current state could reduce your symptoms of depression. And in truth, studies have shown just that.
Many popular diets– including many foods in the American diet – are high in refined sugars and processed foods that can destroy normal gut microbiota and increase your risk for mood disorders. 14 In many cases, though, just reducing your intake of these foods can seem to help but isn’t enough. If your gut microbiome is susceptible to otherwise “healthy” foods, you may also not find any resolution to your symptoms. Even foods like spinach, cale, or fermented foods that are often associated with a healthy gut may not be good for your gut right now. With Viome’s Gut Intelligent Test , you can get deep insight into how your microbes interact with the food you eat and how to improve the diversity of your microbial activity. It is now possible to channel a healthier gut by focusing on how unique your responses are, instead of resorting to “fad” dietary habits that won’t do you or your gut justice long term.
Viome’s focus to eliminate the words “chronic disease” from our vocabulary has included clinical and efficacy trials that connect personalized analysis of your gut microbiome to provide you with distinct food recommendations based on your needs. In an effort to lower symptoms of depression, Viome has found that certain foods and supplements can be used to decrease inflammation and improve gut health associate with the disease. These foods include supplements like fish oil, a natural anti-inflammatory, and foods like blueberries, rich in antioxidants. However, only Viome’s personalized intervention platform can accurately determine if your gut microbiome can actually obtain the benefits of these foods, without contributing to other negative effects based on the limitations of your microbial activity. For example, you may not benefit from a fish oil supplement if you reported being on blood-thinner medications. Similarly, blueberries may spike your blood sugar but cause little or no response in someone else. Your personal microbe activity could suggest you benefit from fruits rich in ellagic acid while your sister may not. This might mean she would benefit instead from other natural antioxidant sources like strawberries or raspberries.
In short, it is not just the food an individual eats but the individual characteristics including what the gut microbiome does with the food that matters when determining what foods are "healthy" for them. Optimizing the gut microbiome with personalized recommendations based on an individual's unique gut biochemistry can play an essential role in preventing and reversing chronic diseases.
Already Viome has heard from thousands of users who reported positive changes in their mood and symptoms. Customers who suffer from mood disorders are among those who seem to report the most improvement mentally and overall after following the Viome plan for several months. Additionally, we have identified biological signatures within the gut microbiome associated with these mental conditions that inform more precise food and personalized supplement recommendations to help combat this growing disease. We’re already working to expand this data to get more actionable recommendations that redefine strategies to improve mental health status. Be prepared to see big changes in the way we approach psychological disorders. By combining brain and gut microbiome research, targeting changes in our gut microbes could be the cure for many mental disorders and neurological diseases.
Ultimately, remember: depression does not define you. You are stronger than the sum of your gut microbes. You are a complex system of biological miracles, working together to function as a superorganism. Take control of your health - starting from the inside - and watch as your symptoms melt away and reveal your true superhuman self. We’ll be here along the way to cheer you on!
In honor of Race to 2 Million, over the next two weeks through September 2nd we’ll be donating 5% of total sales to the Never Alone movement, a cause that aims to help young adults support each other during difficult times of mental health. By tearing down the stigma behind mental health, we can begin to rebuild the mental wellbeing so essential to living a healthy and fulfilling life by providing these young adults the tools to work through it.
Resources:
https://www.healthline.com/health/depression/facts-statistics-infographic#1
Chiu M, Lebenbaum M, Cheng J, de Oliveira C, Kurdyak P. The direct healthcare costs associated with psychological distress and major depression: A population-based cohort study in Ontario, Canada. PLoS One. 2017;12:e0184268.
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Sudhof TC, Malenka RC. Understanding synapses: past, present, and future. Neuron. 2008;60:469-476.
Chaudhury D, Liu H, Han MH. Neuronal correlates of depression. Cell Mol Life Sci. 2015;72:4825-4848.
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Ludwig PE, Varacallo M. Neuroanatomy, central nervous system (CNS). StatPearls. Treasure Island (FL)2019.
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Shi N, Li N, Duan X, Niu H. Interaction between the gut microbiome and mucosal immune system. Mil Med Res. 2017;4:14.
Schiepers OJ, Wichers MC, Maes M. Cytokines and major depression. Prog Neuropsychopharmacol Biol Psychiatry. 2005;29:201-217.
Jiang H, Ling Z, Zhang Y, et al. Altered fecal microbiota composition in patients with major depressive disorder. Brain Behav Immun. 2015;48:186-194.
Zheng P, Zeng B, Zhou C, et al. Gut microbiome remodeling induces depressive-like behaviors through a pathway mediated by the host's metabolism. Mol Psychiatry. 2016;21:786-796.
Wang T, Hu X, Liang S, et al. Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats. Benef Microbes. 2015;6:707-717.
Slyepchenko A, Maes M, Jacka FN, et al. Gut microbiota, bacterial translocation, and interactions with diet: pathophysiological links between major depressive disorder and non-communicable medical comorbidities. Psychother Psychosom. 2017;86:31-46.
