What Is the Gut Microbiome and Why Is it So Important?

Within the gastrointestinal (GI) tract lives a community of microorganisms called the gut microbiome, also called the gut flora and gut microbiota. The gut microbiome not only plays a crucial role in digestion and metabolism, but forms part of an important relationship between the gut and the rest of the body.  

The Gut Microbiome Helps Regulate Mood

The gut microbiota interacts with certain cells and neurons (nerve cells) within the gut to produce mood-regulating neurotransmitters (chemicals that relay signals between nerve cells), including serotonin, GABA, and dopamine. Scientists estimate that as much as 90 percent of serotonin is produced in the gut. Serotonin is well-known for its effect on happiness, feelings of well-being, and even regulating anxiety. 

The gut microbiota communicates with the gut-brain axis (a communication network between the enteric nervous system found in the GI tract and the central nervous system), forming a relationship between the emotional and cognitive functions of the brain with the intestines. For example, scientists have linked a specific bacteria in the gut, called Campylobacter jejuni, to the onset of symptoms of anxiety

The Gut Flora Maintains a Healthy Immune System

Researchers have discovered that roughly 70 percent of the body’s immune system and 80 percent of plasma cells (a type of immune cell) lies within the GI tract. The gut microbiota and the gastrointestinal immune system interact and have a beneficial relationship: the gastrointestinal immune system helps promote the growth of beneficial bacteria and maintain a balance among the various microorganisms of the gut flora, while the gut microbiota supports the development of immune cells. 

The Gut Microbiota Protects the Brain

A study published in the Journal of Experimental Biology observed the effects of gut microbiota on memory formation in mice. Researchers conducted memory tests, like object recognition and maze completion. Some mice were bred with gut flora and some mice were bred with no gut flora (germ-free). When none of the mice were placed under stress, results showed that germ-free mice had problems with memory, while mice with gut flora did not. This suggests that the gut microbiome may affect memory formation.

How Can You Maintain or Improve Gut Health?

The key to maintaining a healthy gut microbiome is to ensure diversity and balance between beneficial bacteria and potentially harmful bacteria. Some ways in which people can do this include:

  • Eating foods rich in prebiotics: Prebiotics are plant fibers found in vegetables and whole grains. Beneficial bacteria grow by fermenting prebiotics in the large intestine.
  • Eating foods rich in probiotics: Probiotics are live beneficial bacteria that are found inside the gut and also in supplements and certain foods, like yogurt, sauerkraut, and miso.
  • Eliminating processed foods: Processed foods can negatively affect the gut flora, leading to inflammation in the intestines and interrupting the proper interaction between the gut microbiota and the gut-brain axis.  

Finding ways to manage and reduce stress: Stress can cause gut flora to become imbalanced and even less diverse.