The old adage goes, “If there’s a Netflix show about it, then it needs no introduction” (or something).
So yes, thanks to shows like Hack Your Health: The Secrets of Your Gut, the gut microbiome has solidified its way into the mainstream. As you read this, you’re most likely aware that trillions of microorganisms — a good mix of bacteria, viruses, and fungi, among others — live inside your gastrointestinal tract. You probably also know that these species aren’t sitting there idly in your gut. They’re taking up nutrients, producing their own, and influencing your health in more ways than you could imagine.
For example, the show goes into mesmerizing detail about how our gut microbiome shapes our relationship with food, from digestive patterns to different cravings. These microorganisms also bear the most responsibility for the person-to-person variations in how we metabolize certain foods. Indeed, differences in microbiome composition can explain the difference in blood sugar responses between you and a friend after eating from the same crop of apples.
Today, we’re covering a topic the show briefly probed into: the gut microbiome’s impact on our brain health. Brain health comprises cognitive function, motor and sensory ability, emotional regulation, stress management, and overall mental well-being in the absence of neurological disorders [1].
The microbiome affects all these facets through the increasingly researched gut-brain axis.
What’s the Gut-Brain Axis?
In recent years, scientific discoveries have begun to shed light on the dynamic interplay between our gut microbiome and central nervous system. Research reveals the microbiome’s active involvement in fundamental neurological processes, including the development of the blood-brain barrier, the generation of new neurons, and the maturation of different types of cells in the nervous system [2].
So, how are all these processes possible? Through the gut-brain axis.
That’s a complex network of neurons, proteins, and neurotransmitters facilitating communication between the gut and the brain through different modes. For instance, compounds synthesized by gut bacteria can enter the bloodstream similarly to how nutrients are absorbed from food. Plus, there are special nerves, such as the vagus nerve, that act as channels, shuttling signals between the gut and the brain. Immune cells — a staggering 70% of which are located in the gut — can also be activated by gut microbes and relay messages to the brain through these nerves [3].
Notably, interest in the gut-brain axis originates from the observation that people with different neurological and psychiatric conditions also often report gastrointestinal issues, such as diarrhea and constipation. This correlation prompted the question: which system is influencing the other?
In reality, it’s a two-way street. The brain impacts the gut, the gut impacts the brain, and the microbiome is a key player in between. Disruptions to the gut microbiome, whether due to infection or changes in diet, can set off a chain reaction in the body that reverberates psychologically, behaviorally, and neurologically [3].
Consider this: certain gut bacteria can produce oxytocin, commonly known as the “love hormone,” which promotes social bonding. On the other hand, some bacterial byproducts have been linked to symptoms of depression and anxiety, such as elevated inflammatory mediators. Still, certain bacterial strains produce compounds that aid in stress resilience and emotional balance [4].
Moreover, emerging evidence suggests that the gut microbiome plays a pivotal role in predisposing individuals to neurodegenerative conditions like Alzheimer’s and Parkinson’s diseases, as well as neurodevelopmental disorders such as autism. Interestingly, substances like synuclein, implicated in Parkinson’s disease pathology, are synthesized by gut bacteria and can traverse nerve pathways from the gut to the brain, potentially influencing disease progression [5].
How to Nourish Your Gut Microbiome for Brain Health
Across a person’s lifespan, the gut microbiome tends to undergo certain changes. It undergoes rapid shifts from infancy to around age three, remains relatively stable until middle age, and then experiences increased variability from late adulthood onward [6].
Like our genomes, each person’s microbiome is unique, but there’s a crucial difference between the two that offers significant potential for enhancing health.
“Unlike your genome, which you can’t do much about except blame your parents and grandparents, your microbiome is potentially modifiable.” [7] Professor John Cryan Principal Investigator at the APC Microbiome Institute
To paraphrase Professor Cryan, your gut microbiome isn’t a life sentence. It’s dynamic and responsive to various factors, providing opportunities for positive change throughout your life. Scientists have been studying several strategies to improve the health of our gut microbiome and, by extension, our brain health.
Below, we’ll explore the five most important and straightforward strategies you can immediately adopt:
1- Diversify Your Diet
A diverse diet is like a feast for your gut microbiome. Each type of food you consume can foster different types of beneficial bacteria, promoting a rich and varied gut ecosystem. This diversity, particularly in plant intake, is good for both your gut and brain.
The “American Gut: an Open Platform for Citizen Science Microbiome Research” landmark study provides compelling evidence for this strategy. The study involved 10,000 participants from the US, UK, and Australia, who provided stool samples for researchers to compare their different microbiome compositions.
Remarkably, the study found that participants who ate 30 or more different plants per week were more likely to have certain beneficial gut microbes than those who ate just 10 [8].
What could be behind this fascinating discovery? The wealth of dietary fiber we get from plants. Dietary fiber is the primary energy source of our gut microbiome. As a reward for feeding them fiber, gut microbes produce short-chain fatty acids (SCFAs). These byproducts of fiber fermentation nourish our bodies in different ways, including boosting brain health [9].
Supporting this theory, a two-decade study of over 3700 adults found a direct correlation between fiber intake and dementia rates. Those consuming the most fiber (18–65g daily) had a 26% lower risk of dementia compared to those consuming the least (2–10g daily) []. The SCFAs produced by the gut microbiome could be the reason behind this [10].
2- Cut down on Sugar
Excessive sugar consumption can disrupt the gut microbiome, leading to a decrease in bacterial diversity and altered metabolism.
A study conducted at Columbia University Irving Medical Center found that dietary sugar alters the gut microbiome, setting off a chain of events that leads to metabolic disease, pre-diabetes, and weight gain. The study revealed that sugar was responsible for eliminating certain beneficial bacteria and immune cells in the gut, which are crucial for maintaining gut health [11].
Cutting down on sugar, particularly added sugar, can help restore balance in the gut microbiome. Moreover, reducing sugar intake can help reduce inflammation, a common effect of excessive sugar consumption. Chronic inflammation can negatively impact brain function and has been linked to various neurological conditions [12].
3- Avoid Ultra-Processed Foods
Ultra-processed foods, characterized by their high content of artificial additives, unhealthy fats, and sugars, are common features of the Western diet. These foods are not only nutritionally poor but also can wreak havoc on the gut microbiome, which in turn can influence brain health.
Researchers found that ultra-processed foods alter the gut microbiome, leading to disruptions in its composition and functions. This disruption is associated with an increased risk of chronic metabolic diseases and neurodegenerative diseases [13].
Moreover, the study emphasizes the need for stricter public health strategies regarding access to and development of ultra-processed foods. Avoiding ultra-processed foods can lead to many benefits such as increased concentration and focus, and decreased inflammation. This is a call to action for us all to reconsider our dietary choices and opt for natural, fiber-rich foods over ultra-processed ones.
4- Stay Hydrated
Hydration is often overlooked when discussing gut health and brain function, yet it plays a crucial role in both. Water is essential for the proper functioning of every cell, tissue, and organ in our bodies.
Staying hydrated helps maintain the integrity of our intestinal lining, which is crucial for preventing leaky gut, a condition that can lead to inflammation and disrupt the gut microbiome [14].
Interestingly, a study involving participants from the US and UK found that the source and intake of drinking water are associated with distinct gut microbiome signatures. The researchers discovered that the source of drinking water, whether it be bottled, tap, filtered, or well water, ranked among the key contributing factors explaining the gut microbiome variation.
In particular, individuals who primarily drank well water exhibited distinct gut microbiome signatures, including higher beneficial gut bacteria. Conversely, these individuals had lower levels of harmful bacteria often associated with a Western diet and various health issues.
Moreover, the study found that low water drinkers also showed differences in gut microbiome compared to high water drinkers, with a higher abundance of a species associated with foodborne illnesses that can negatively impact gut health [15].
5- Consider Probiotics
Probiotics, often referred to as “good bacteria,” are live microorganisms that, when consumed in adequate amounts, confer health benefits. These benefits extend beyond the gut, influencing brain health through the gut-brain axis.
One way to incorporate probiotics into your diet is through fermented foods. These foods, such as yogurt, kefir, and kimchi, are rich in probiotics and have been associated with improved gut health. A study at Stanford School of Medicine found that a diet high in fermented foods enhances the diversity of gut microbes and decreases molecular signs of inflammation [16].
Clinical trials have also shown promising results for the use of probiotics in brain health. For instance, a randomized double-blind placebo-controlled trial found that 12-week probiotic supplementation improved the cognition status of Alzheimer’s patients compared to placebo [17].
Another interesting development in this field is the emergence of “psychobiotics.” These are a special class of probiotics that can affect our mental state due to their interaction with our gut microbiome. Psychobiotics stimulate the production of compounds, such as the aforementioned SCFAs, that play crucial roles in brain function, including mood regulation and cognitive processes [18].
Conclusion
As we’ve explored, the world of the microbiome is vast, and its relationship with brain health is intricate and delicate. But don’t be overwhelmed. Remember, if it can be measured, it can be managed. And indeed, there are ways to measure your microbiome’s characteristics and performance.
That’s where platforms like Viome come in. Viome that uses advanced RNA-based testing to provide insights into your gut microbiome. Viome tests help you discover the best foods, supplements, and probiotics for your health, addressing root causes and supporting overall wellness and longevity.
In a pre-print study, Viome’s precision nutritional recommendations resulted in improvements in clinical outcomes by 36% in severe cases of depression and 40% in severe cases of anxiety [19]. This supports the integration of precision food and supplements into the standard of care for these chronic conditions.
We’re proud to have Viome as a part of our extended wellness ecosystem. They’re offering Rejuve.AI community members an exclusive discount on all Viome orders. So why wait? Start your journey towards a healthier gut and a healthier brain today through this link.
References
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