Gut Biome: Happiness and Sadness from the Gut

On the topic of happiness, it’s worth exploring the biological side of how we experience different states of elation or depression. More specifically, is there a possible link between gut biome and depression?

A study published in Nature Microbiology posits that clinical depression may be associated with certain bacteria found in the gut.

The initial theory about the relationship between gut biome and depression stemmed from the fact that our intestine is host to an entire ecosystem of bacteria, archaea, fungi, and viruses. These organisms have the capacity to influence the way our body functions, including neurological processes.

Microbiologist, Jeroen Raes of the Catholic University of Leuven in Belgium, found that a majority of our gut bacteria are able to produce neurotransmitters, which are chemicals similar to dopamine and serotonin that connect to brain neurons. By acting as chemical messengers, gut bacteria travel to our brain receptors, therefore, directly affecting mood.1

Key points from Raes research:

  • The gut bacteria of over 2,000 European participants were examined.
  • 532 strains of bacteria were studied to find out if the bacteria could produce neurotransmitters.
  • More than 90% of the bacteria in the study showed the ability to produce one or more chemical transmitters.
  • The vagus nerve, the longest nerve that stretches from the brainstem to the lowest part of the intestines, was identified as the pathway for the transmitters.
  • A common factor among depressed participants was low levels of Coprococcus and Dialister bacteria in the gut.2

A Multi-Perspective Approach to Wellness

Approaching health and mental wellness from multiple disciplines – similar to our discussion about autoimmune disorder and depression – provides affected people with more options for interventions. The complexity of how our body responds to treatments suggests that a single formula does not exist and that a multi-perspective approach to wellness is beneficial for everyone.

Here are a few more research-supported studies that suggest how to naturally achieve emotional and physical balance.

Probiotics and Fermented Food

Fermented food produces natural probiotics. Adding this food category to our diet reduces gut inflammation and intestinal issues. Sauerkraut, kimchi, miso, and kombucha are highly recommended by naturopaths and nutritionists.

Read the full study here.

Less Sugar and Sweeteners = Better Mood

Excessive amounts of sugar or artificial sweeteners may cause gut dysbiosis – an imbalance of gut bacteria. This imbalance causes our cognition to be less adaptive to external stimuli – a symptom evident among people with depression and mood disorders. 

Research led by the College of Veterinary Medicine at Oregon State University examined the sucrose-based (sugar-rich) diet of mice. Results have shown that anxiety levels, memory and spatial bias are impaired with the said diet due to sugar’s effect on the gut microbiome.

Read the study summary here.

Exercise and Happiness

Professional athletes from an international rugby union squad were examined to determine the relationship between exercise and gut biome. Compositional investigation of the two team’s gut biome was explored. In addition, each participant completed a detailed food frequency questionnaire.3

The results provided evidence that people who engaged in regular physical activity had a greater diversity of bacteria in their gut (22 distinct phyla). Such diversity positively impacts protein consumption which is a vital process for the brain when regulating mood.

Read the summary of the research here.

There is so much more research on the link between gut biome, depression, and other mood disorders. New discoveries emerge every day about the contribution of holistic health practices to a variety of known mental health concerns.

Let’s encourage openness and curiosity. There is more than one way to thread a needle.

If you have any interesting research you’d like to share, please comment below.




1. Scientists Find Possible Link Between Gut Bacteria and Depression

2. Specific Gut Microbes Linked with Depression Study

3. Effects of probiotics on gut microbiota