With the rise of focus on gut health in the wellness and supplement industry, you’ve probably heard the term “gut-brain connection” or “gut-brain axis”. The digestive system is even colloquially referred to as a “second brain”.
Probiotics, greens powders, supplements, and other products promise to streamline digestive health, claiming it will positively affect your mood, cognitive function, and physical condition. But is it true?
Yes. But the gut-brain connection is more complex than the “second brain” nickname makes it sound.
What’s Going On in Your Gut?
Your gut is much more than a tube that moves food from one end to the other. It breaks food down, absorbs nutrients, houses trillions of microorganisms, and produces compounds that can influence processes throughout the body.
Here’s the quick tour:
Food Gets Broken Down
Digestion actually starts in your mouth, where chewing and enzymes begin breaking food apart. Your stomach continues the process with acid and digestive enzymes, turning what you ate into a semi-liquid mixture called chyme before it moves into the small intestine.
Nutrients Get Absorbed
The small intestine does most of the nutrient absorption. Its lining is covered in tiny finger-like structures called villi that dramatically increase its surface area, helping vitamins, minerals, amino acids, fats, and carbohydrates move into the bloodstream.
Your Microbiome Gets to Work
By the time food reaches the large intestine, some components, especially certain fibers, haven’t been fully digested. That’s where much of your gut microbiome gets involved.
Trillions of bacteria and other microorganisms ferment these compounds and produce substances that can affect the gut itself and other parts of the body.
Gut Bacteria Make Useful Compounds
One important result of that fermentation is the production of short-chain fatty acids, which help nourish cells in the colon and play roles in metabolism and immune function. Some gut bacteria also contribute to the production of certain vitamins.
This is one reason why what you eat can influence which microbes thrive in your gut and what they produce.
The Large Intestine Finishes the Job
Finally, the large intestine absorbs much of the remaining water and electrolytes. What the body doesn’t need is compacted and eventually eliminated.
And this is where the gut-brain connection is vital. All of that microbial activity, chemical signaling, and nutrient processing doesn’t stay isolated in your digestive tract. Your gut is constantly communicating with your brain.
How Does Digestive Function Affect the Brain?
Okay, now let’s bring the discussion of digestion all the way up and into the brain. What is the connection? Two things:
Diverse Bacteria Populations
As we said, there are trillions of little workers representing hundreds of bacterial species that make the digestive system work. But they also send signals to the brain, mainly through the vagus nerve, a major communication pathway, influencing our physical and mental state.
Diversity is key in a healthy microbiome. Good bacteria like Lactobacillus and Bifidobacterium help digest food, producing vitamins and supporting your immune system. Others, the bad ones, can contribute to inflammation and gut issues. But there's also a third group, the opportunists, who can swing one way or another depending on the environment.
An Autonomous Nervous System
No, not the autonomic nervous system. This is a fourth nervous system separate from the CNS, ANS, and PNS. The gut’s nervous system is called the enteric nervous system (ENS). It contains millions of neurons that create signals that mimic neurotransmitters. While connected to the central nervous system, the ENS has some autonomy, regulating digestion, gut motility, and even some immune responses.
This bidirectional communication network between the gut and brain allows them to influence each other, impacting everything from digestion and nutrient absorption to mood, stress levels, and even cognitive function.
What Does the Research Say About the Gut-Brain Connection?
A 2018 review of the literature on microbiome, mood, and mental health cited several compelling human studies, including:
- A 2002 study on adults suffering from stress-induced exhaustion found that L. acidophilus, B. bifidum, and B. longum supplements improved subjects’ general condition by 40.7% after 6 months.
- A 2007 study on the effects of probiotic yogurt found that subjects who started with a low mood reported mood improvements.
- A 2009 study on adults with chronic fatigue found that 2 months of supplementing with L. casei significantly improved Beck scores on an inventory used to evaluate stress and reactivity.
- A 2011 study on healthy human volunteers found that consuming L. helveticus and B. longum reduced negative sensations, low mood, irritability, and medical-related apprehension, as well as self-blame on a coping checklist and better focus on problem-solving.
- A 2015 study on a multi-strain supplement of B. bifidum, B. lactis, L. acidophilus, L. brevis, L. casei, L. salivarius, and L. lactis significantly reduced cognitive reactivity to aggressive thoughts, intrusive thoughts, and rumination.
A 2023 review of the gut’s ecosystem, cognition, and brain disorders cited several fascinating findings:
- “An altered quantitative and qualitative composition of the gut microbiome can induce the production of metabolites with cytotoxic effects, promote neuroinflammation, and disrupt immune cell function. This results in the inhibition of synaptic transmission and gamma oscillations in... a brain region that plays a crucial role in innate and cognitive behavior.”
- “Studies in GF mice document the importance of bacterial colonization of the gut after birth for the development of brain functions and expression of miRNAs and messenger RNAs in the hippocampus that cannot be reversed by colonization of gut microbiota in adolescent mice.”
- “Microbiota seem to be crucial for the formation of stress response-related brain circuits, while emotional and physiological stress affects the gut... Stress causes dysbiosis, which consecutively leads to altered synthesis of biologically active substances, including neurotransmitters...”
Is a “Gut Feeling” a Real Thing?
It’s clear the gut and the brain are intimately linked, each affecting the other, each unable to fully control the effects of the other. The next question that many of us have: If the gut-brain axis is real, does that mean gut feelings are real?
It certainly seems so.
Of the different pathways the gut uses to communicate with the brain, some signals are sent to crucial memory, learning, stress, and decision-making areas, such as the brain’s stress adaptation axis, where a healthy gut supports memory function in key regions of the brain. And while the CNS is the first player to receive most gut signals, evidence indicates these signals are passed on to those higher-order brain regions involved in complex and intuitive decision-making.
Keeping Both Your Brains on Track
Your gut is packed with such a diverse multitude of microorganisms that consistency is key when it comes to keeping your digestive system functioning well. The goals? Regular movement, effective nutrient absorption, balanced levels of good bacteria.
Here are a few ideas to help:
- Exercise. Is there anything exercise can’t fix? Physical activity keeps your digestive system active and can help regulate bowel movements. Aim for at least 30 minutes of moderate-intensity exercise most days of the week.
- Stay hydrated. Again – nature’s cure-all. After all, we’re, like, 70% water. Drinking plenty of water throughout the day keeps your digestive system moving smoothly and prevents constipation.
- Keep a balanced diet. Concentrate on nutrition and avoid stuff like chemical-laden energy drinks and sugary coffee. Chemicals, processed, sugary, and fatty foods can disrupt gut bacteria balance and contribute to digestive issues.
- Eat mindfully. Read: stop scarfing your dinner. Savor your food. Chew it completely and eat slowly to aid digestion.
- Increase fiber intake. Aim for 25-35 grams of fiber daily from whole grains, vegetables, fruits, and legumes. Fiber keeps you feeling full, promotes regularity, and nourishes all that good gut bacteria.
- Eat more fermented foods. Fermentation results in natural probiotics. Incorporate fermented foods like yogurt, kimchi, or kombucha into your diet for a natural source of probiotics.
Why Chicory Root Supports Brain & Body
Another habit that can help you in your endeavor to get your digestive system back in line is a well-being supplement with prebiotic fiber, namely, inulin. Found in high levels in chicory root, inulin supports gut health via:
- Antimicrobial actions: lessens adhesion of bad bacteria to cells.
- Antiallergenic actions: balances inflammatory and immune responses to disturbances.
- Antidiabetic actions: aids in blood sugar regulation.
- Microbiome support: encourages good bacteria to flourish.
- Immune support: has hepatoprotective, immunomodulatory, diuretic, and restorative effects on the liver.
The prebiotic fiber in MTE supports the brain-boosting nootropics in the formula. Coupled with adaptogens, a daily drink of MTE’s energy supplement powder can offer well-rounded support for your mind and body.
Order MTE and give your daily energy routine a little more support from the gut up.
