What Does Your Gut Have to Do With Your Mood?

We’ve seen a dramatic rise in stress, anxiety, and depression in recent years (World Health Organization, 2023). Although the authoritative Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013) lists symptoms of anxiety and depression, it fails to address one key factor: the relationship between our brain and our gut—or specifically, our gut microbiome, the trillions of bacteria, fungi, protozoa, and viruses that live within our digestive system.

Yet research has found that our gastrointestinal tract contains over one hundred trillion microorganisms essential to our emotional and physical health (Rieder and colleagues 2017). The gut microbiome is connected to our brain function by the gut-brain axis, an internal, bidirectional pathway between the gut and the brain via the vagus nerve. Research has shown that this complex communication system not only influences intestinal activities like digestion and motility, but also helps regulate our immune and pain response system, metabolism, mood, social behavior, and cognition.

To find out more about the powerful connection between the microbiome and our mental health, I talked to Raja Dhir, co-founder of Seed Health, which brings together international researchers to find science-based microbial solutions for personal and planetary health. Dhir is deeply committed to conservation on many levels. He works to protect our marine environment and the vulnerable honeybee populations as well as to help us maintain our ecosystems, including the community of microbes that support the life within us.

Dhir explains that we have microbiomes in many areas of the body including the skin, mouth, and genitals. He works with scientists from major universities to study how these microorganisms affect our mood, weight, gastrointestinal function, immune system, and overall health. He’s now seeing many studies where “you find a very high correlation of people with psychological challenges and how that correlates with disrupted digestion and gastrointestinal function.”

What We Eat Can Affect Our Mental Health. I was amazed to find just how much what we eat affects our mental health. Research has revealed that highly processed foods that reduce microbiome diversity are associated with an increased risk of mental disorders (Dawson, Dash, and Jacka, 2016). In both animal and human models, randomized studies have revealed the beneficial effects of probiotics on mood (Lange and colleagues, 2020). Research has revealed the power of probiotics to treat and prevent anxiety and depression (Rieder and colleagues, 2017). A British study found that depressed people who consumed a probiotic yogurt drink for three weeks experienced a significant improvement in mood (Benton, Williams, and Brown, 2007), and a French study (Messaoudi and colleagues, 2011) found a significant decrease in anxiety and depression when people took a probiotic formulation of Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 for 30 days.

Helpful Microorganisms in Probiotics. Researchers have studied the many diverse microorganisms in probiotics and their health-promoting effects. They’ve found that in infants, a healthy microbiome trains the immune system, establishing a strong foundation for life. This process involves the Bifidobacterium microorganism, which primes the immune system through breastfeeding. In later life, Dhir says, if we have a sub-optimal microbiome, we can “tilt that in a positive direction through the microbial inoculum we consume.” Live bacteria occur naturally in yogurt, kombucha, and fermented foods such as pickles, sauerkraut, and miso. However, most “probiotic” food or beverages do not meet the scientific definition of a probiotic and have not been subjected to controlled studies in humans to demonstrate a health benefit beyond the food or beverage itself. There are some clinically studied probiotic strains to promote whole-body benefits, including regularity, ease of bloating, gut-immune function, gut-barrier integrity, glowing skin, and heart health.

How to Build a Healthier Microbiome. We can begin cultivating a healthier microbiome by living a more balanced life. Dhir recommends “good sleep, stress management, and exercise” as well as avoiding “unnecessary or gratuitous medication like antibiotics and other microbiome-disrupting drugs.” We need to stay away from “what’s referred to in the scientific literature as processed and ultra-processed foods: refined grain, industrially processed meat, packaged foods, and caloric beverages.” Instead, we should choose foods rich in flavonoids, fermentable fibers, and polyphenols. Foods high in fiber include seeds, nuts, oats, beans, peas, berries, whole grains, and vegetables such as broccoli, Brussels sprouts, beets, carrots, and squash. To those of us less familiar with scientific terminology, polyphenols have powerful antioxidant, anti-inflammatory, anti-viral, and anti-cancer properties, and flavonoids are the largest group of naturally occurring polyphenols. To help us choose these health-promoting foods, Dhir offers “a simple rule of thumb. If it’s colorful, it’s probably rich in flavonoids. Green, orange, red, blue, purple.” It's a rainbow of possibilities to improve our health. He encourages us to add more of these foods to our daily meals, “You can start by adding a different one each day and work your way up.”

By maintaining a more balanced life and becoming more aware of the food we eat, especially helpful probiotics, we can maintain a healthier microbiome, and feel better both emotionally and physically.

Source: Raja Dhir, used with permission

This post is for informational purposes and should not substitute for psychotherapy with a qualified professional.

© 2024 Diane Dreher, All Rights Reserved.