With the New Year solidly underway, you’re likely being inundated with trendy health tips practically everywhere you turn. While we’re not ones to jump on bandwagons, one health trend that we want to see more discussion about is the idea of the gut-brain connection. While traditional holistic medicine systems, such as Ayurveda, have long touted the importance of digestive health, it wasn’t until more recently that conventional Western medicine caught on. In fact, we are now beginning to understand just how important having a healthy digestive system is, for all aspects of our health.

Over the last few years we’ve seen an increase in research specifically aimed at better understanding “the gut-brain connection.” Currently, most research around the gut-brain connection aims to explore the relationship between digestive and mental health.

What is the gut-brain connection?

Have you ever experienced the sensation of butterflies in your stomach before a big event? This is a perfect example of how your mental state can influence your digestive experience. In fact, we now know that this connection is bidirectional—meaning that your mental state can influence digestion and your digestive state can influence your mental status. It’s called the gut-brain axis and it’s facilitated by microbes in our digestive tract. So, how exactly does this work? Let’s take a closer look.

How does the gut-brain axis work?

Within our digestive system we have a community of microorganisms, including bacteria, viruses, yeasts, protozoans, and fungi, that we collectively refer to as the gut microbiota. Along with maintaining our intestinal mucosa and facilitating digestion, the gut microbiota can also communicate with the central nervous system via the vagus nerve.

The vagus nerve is a bidirectional communication channel that connects the gut to the brain and spinal cord. It uses neurotransmitters, such as serotonin, dopamine, and GABA, to send messages between the enteric nervous system (within our gut) and the central nervous system (our brain). Researchers have found that specific species of gut microbes can directly produce serotonin. In fact, it is estimated that more than 90% of serotonin in our bodies is made in the digestive tract. What does that mean? Serotonin produced by gut microbes can stimulate the vagus nerve and thus alter activity within the brain.

In addition to producing serotonin, gut microbes also produce compounds called short chain fatty acids (SCFAs), which have a beneficial effect on brain function. One SCFA called butyrate acts as our intestinal cells’ preferred fuel source, thus keeping the digestive system happy and healthy. Butyrate can also promote serotonin production. Propionate, another SCFA produced by the microbiota, appears to reduce inflammation and promote insulin sensitivity.

How the gut-brain connection can impact mental health

Gut microbes also appear to influence brain activity through both the immune and endocrine systems. While we won’t explore the exact mechanism here, we do want to point out that there’s an emerging relationship between chronic stress, the gut microbiota, and mental health. Chronic stress can suppress the immune and digestive systems, thereby lowering the body’s defense against pathogens. This can lead to inflammation and possibly promote intestinal permeability and leaky gut.

On top of that, certain pathogenic bacteria appear to have a preference for stress-related neuroendocrine hormones. Increased inflammation and reduced microbial diversity can both negatively impact mental health, from chronic stress to anxiety and depression. Just another reason why stress management is so important!

How to support the gut-brain connection for better health

Having a diverse microbial community is essential for supporting mental health and reducing depression and anxiety. To best support a diverse gut microbiome, we recommend including a variety of pre- and probiotic foods daily in your diet. In addition to effective stress management and anti-inflammatory strategies, eating colorful, plant-based foods will help support microbial diversity and optimize your gut-brain axis.

Prebiotic foods to add to your diet:

1. Sunchokes, artichokes, asparagus, onions, garlic, leeks, beets, broccoli, fennel
2. Bananas
3. Legumes—lentils and beans

Probiotic foods to add to your diet:

1. Sauerkraut, kimchi, raw pickled vegetables
2. Yogurt, kefir
3. Miso, tempeh

Interested in learning more about how your gut might be impacting your mood or other health concerns? Schedule a free, 15-minute consultation with us!

Dr. Cassie Wilder

Dr. Cassie Wilder is a registered Naturopathic Medical Doctor (NMD) and founder of MIMC. Her passion is empowering her patients through education, understanding, and support through their healing journey. After graduating from Iowa State University with a Bachelors of Science in Kinesiology and Health, Dr. Wilder earned her Doctorate of Naturopathic Medicine from Southwest College of Naturopathic Medicine & Health Sciences, a fully accredited and nationally recognized institution in Phoenix, AZ. During her clinical training, she received extensive hands-on training with many leading experts in the field of functional medicine and developed a passion for treating hormonal imbalances, thyroid disorders, cardiovascular concerns, and adrenal fatigue.