More Than a Gut Feeling: How Gut Microbiome Influences Mental Health

Science reveals the invisible world inside us, the microbiome, profoundly affects mental health, immunity, and much more

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Can our tiny internal world of bacteria, fungi, viruses, and other microorganisms hold greater significance than we think when it comes to mental health?

Current researchers think so, and so did Hippocrates, who famously said about 2,500 years ago that “all disease begins in the gut.”

The idea that the gut is closely connected to overall health, including mental health, has become an important area of research as scientists uncover unexpected and important influences of the gut microbiome—the community of microbes living in our gut.

Mindful Microbiome: The Scientific Consensus

Current research, including a 2019 study published in the American Physiological Society Journal, reveals a complex, captivating relationship between the gut microbiome and the intricate network called the gut–brain axis.

In a 2016 Cell article, scientists highlighted that the past two decades have seen a surge of studies uncovering the significant influence of microbiota on the physiology and metabolism of multicellular organisms, with implications for health and disease.

The gut microbiome affects mental health by producing neurotransmitters, influencing the immune system, and affecting emotional resilience. This sophisticated communication system is like a superhighway that involves biochemical and nervous system pathways, running in two directions and connecting the brain and gut.

“The science behind this is solid,” Shawn Talbott, who holds a doctorate in nutritional biochemistry, told The Epoch Times. Mr. Talbott has studied stress resilience and the microbiome for the past 20 years.

“We’ve known for over 100 years that there are bacteria in the gut, but the reason this is exploding is now is we can measure the microbiome at a level of sensitivity that we couldn’t 10 years ago,” he said.

At one point, scientists even thought that bacterial cells in the body outnumbered human cells 10-fold, but newer research has suggested the ratio might be closer to 1-to-1.

What Makes the Gut Your ‘Second Brain’?

While the gut does produce a considerable amount of serotonin, dopamine, and gamma-aminobutyric acid, key neurotransmitters involved in feelings of happiness, motivation, and relaxation, respectively, the topic remains an active area of investigation.

Serotonin, in particular, has been a neurotransmitter of focus for some time. A 2020 study published in the Advances in Nutrition journal showed that more than 90 percent of serotonin is located in the gastrointestinal tract.

“How you feel is not just in your head; it’s also in your gut,” Mr. Talbott said.

Emerging science suggests the microbiome profoundly influences the immune system, with significant implications for mental health.

Imbalances in the microbiome, also known as dysbiosis, can trigger inflammation, linked to various psychiatric disorders, including bipolar disorder and schizophrenia.

The relationship among the microbiome, gut, and brain also plays a crucial role in regulating emotions and responding to stress.

Recent studies have shown that mice raised in a sterile environment with no bacteria exposure exhibited altered stress responses and anxious behaviors. These findings indicate that exposure to diverse beneficial bacteria may establish a strong foundation for emotional resilience throughout life.

Microbiome Diversity: The More, the Merrier

Studies reveal that greater microbial diversity is associated with improved mental health. Conversely, a limited variety of gut microbes has been linked to an increase in symptoms of anxiety and depression. Moreover, individuals with conditions such as post-traumatic stress disorder and autism spectrum disorder tend to exhibit lower gut microbe diversity.

The Best Foods for a Healthy Gut

It’s very important to eat a whole-food diet to provide the microbiome with the healthy nutrients and fiber that bacteria need to thrive, according to Mr. Talbott. The Mediterranean diet, renowned for its nutritional value, including abundant fiber and antioxidants, can significantly contribute to mental wellness, he added.

A variety of foods such as vegetables, greens, fruits, chickpeas, basil, and garlic serve as excellent sources of prebiotics, nutrients that feed beneficial bacteria. These prebiotics act as the foundational building blocks for cultivating a robust and healthy microbiome. Also helpful are cultured foods such as Greek yogurt and sauerkraut, known as probiotics, because they provide live beneficial bacteria.

The Gut–Brain Axis: New Perspectives and Potential Treatments

Scientists are continually uncovering new information about the relationship between the microbiome and the brain. With each revelation, they gain fresh perspectives on mental illness prevention and treatment.

“We are still in the early days of understanding the microbiome and the gut–brain axis,“ Mr. Talbott said. ”We might learn so much more in the next five years of how gut–brain axis signaling happens,“ he added. ”We don’t know how the science is going to develop. We are at the forefront of it.”