The Gut-Brain Connection Explained

The Gut-Brain Connection Explained—Plus, Supplements to Support It

We go with our gut. Have gut reactions and experience gut-wrenching moments. But these idiomatic phrases aren’t just catchy ways to describe our feelings. They allude to the inextricable link between our stomach and that big, complex organ in our head. In fact, the two are so enmeshed that scientists have dubbed a part of the gut our “second brain,” or “little brain.”

So, it’s no surprise that recent studies have shown our brain significantly impacts our gut health and vice versa. In this article, we’ll explore the gut-brain connection, along with supplements that can help support both organs and nourish the intricate relationship between body and mind.* 

Brain and Gut Biology 101

Though our big brain and little brain share important similarities, there are certainly key differences between them.

Our big brain is part of our central nervous system (CNS), and it controls everything from thought, memory, and emotion to breathing, vision, and temperature. It’s the epicenter of the nervous system as a whole, which includes nerves that extend from the brain and spinal cord out to all parts of the body—including the gut.

Whereas our little brain is a hidden nervous system in the walls of our gastrointestinal tract, referred to as our enteric nervous system (ENS). Rather than help us solve problems or write love poems, it’s involved mostly in controlling digestion. It’s not capable of thinking per se, but it can send out signals and alert our big brain when something is wrong, and it uses the same chemicals and cells as the big brain to do so. It’s in part through these chemicals and cells, specifically neurotransmitters and neurons, that the gut and brain communicate.1,2

The Gut-Brain Axis: How the Two Organs Talk

Without getting too technical, this two-way conversation occurs through multiple pathways along a highly sophisticated network known as the gut-brain axis, which links the ENS and the CNS.3

For example, both our gut and brain contain an abundance of neurons, and these neurons in our stomach and our skull are connected by and communicate via those peripheral nerves. The vagus nerve, often called the modulator of the gut-brain axis, is one of the largest nerves joining the organs and represents a direct connection between them. It plays a major role in nervous system functions such as mood and energy level regulation, as well as the body’s reaction to occasional stress and the ability to concentrate.4

The gut and brain also talk through neurotransmitters such as serotonin, norepinephrine, and GABA. Some of these chemicals are produced in the brain and control our feelings and emotions—think the “fight or flight” response. But perhaps surprisingly, they can also be made by the cells and microbes in our gut and affect various aspects of digestion. A whopping 95% of the body’s serotonin is actually produced in the gut.5 Our gut bacteria also make other chemicals that affect how our brain works and may be involved in the formation of the blood-brain barrier. 6

And, the gut-brain axis includes yet another communication route and connection: the immune system. As you often see us share at Solaray, at least 70% of the immune system is located in the gut; the brain also has its own resident immune cells.7

How to Nourish the Gut-Brain Connection

This is a highly abridged explanation of what is an incredibly involved system. But the take-home message is quite simple: There is a clear physiological link between the brain and the gut. Thus, it’s in our best interest to support that connection so we can keep feeling our best emotionally, mentally, and physically.

One way to do so is to eat a gut- and brain-friendly diet: Load up on fermented foods teeming with beneficial bacteria, such as yogurt, sauerkraut, tempeh, miso, and kefir; foods like oily fish that are high in omega-3 fats (found in high quantities in the brain); as well as tryptophan-rich foods including turkey and eggs (this amino acid is converted into the neurotransmitter serotonin).

Another? Targeted nutrient supplementation. Solaray offers a variety of supplements to support gut health and brain health.* Of course, don’t forget other healthy habits, too, from staying hydrated to practicing good sleep hygiene for quality shuteye.

Mycrobiome Pre- & Probiotics

As we’ve established above, the gut and its microbiome (aka community of microorganisms including “good bacteria,” or probiotics) plays a role in digestion, immunity, mood and brain health, and beyond. Prebiotic and probiotic supplements can help support healthy microbial balance.* Our Mycrobiome® collection offers both types for your comprehensive digestive and overall wellness routine.

Prebiotics act as a source of food for probiotics; these specialized plant compounds help the body’s good bacteria thrive so they can keep doing their work of helping you stay well.* Our Mycrobiome Prebiotic Powders are crafted with scientifically backed ingredients and deliver innovative prebiotic blends. They are non-gritty and enjoyable, mixing easily into your beverage of choice.

Probiotic supplements, on the other hand, provide the beneficial bacterial strains themselves, which are needed to help maintain a healthy gut and a healthy gut-brain connection.* Solaray Mycrobiome Probiotics are expertly designed with Enteric Shield for optimal protection of fragile probiotic cultures.* Each formula features an efficacious mix of unique strains at clinically researched potencies to deliver support you can count on.*

SharpMind Nootropics

Anchored by nootropic ingredients targeted at cognitive health, our SharpMind products take into account the mind-body connection and are specially formulated to offer nutritive support for the nervous system and gut-brain axis.* In addition to clinically supported nootropic nutrients, they also contain nourishing adaptogens and fermented organic mushrooms for synergistic support. Depending on your specific needs, try our EnergyFocusStressMood, and Sleep formulas to help promote mental and emotional well-being.* 

Shop our full digestive support and brain health categories.*

A Healthy Gut-Brain Connection for Overall Health

The nervous system is our body’s command center, controlling almost everything we do. Our brain is its epicenter; from this central hub, nerves branch out and reach all parts of our body, including the gut. Through these nerves and other pathways, the two organs are in constant communication, sending signals back and forth and influencing one another’s health and our health.

Though the science is complex, it underscores a clear and important message: To stay feeling our best, it’s critical to support both our brain and gut. Because of their influential relationship with one another, when things are off in either organ, we can notice changes in digestion, immunity, mood, and more.

By eating a healthy, balance diet and getting additional, targeted nutritive support from prebiotic supplements, probiotic supplements, and nootropic supplements, we can nourish the gut-brain connection for overall well-being.* 


  1. “The Brain-Gut Connection,” Johns Hopkins Medicine,
  2. Debra Bradley Ruder, “The Gut and the Brain,” On the Brain, Harvard Medical School (2017),
  3. Jeremy Appleton, ND, “The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health,” Integrative Medicine 17, no. 4 (2018),
  4. Breit, Sigrid et al. Frontiers in Psychiatry. (2018): 44.
  1. Natalie Terry and Kara Gross Margolis, “Serotonergic Mechanisms Regulating the GI Tract,” Gastrointestinal Pharmacology (2016),
  2. Gerard Clarke et al. “Minireview: Gut Microbiota: The Neglected Endocrine Organ,” Journal of Molecular Endocrinology 28, no. 8 (2014),
  3. Selma Wiertsema et al. “The Interplay Between the Gut Microbiome and the Immune System,” Nutrients 13, no. 3 (2021),

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