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Hey Life Warriors! The gut microbiota is a fundamental part of our health. We hear a lot about it, also called intestinal flora, but not everyone fully understands its importance. We’re going to share a series of three articles in which we’ll explain what the gut microbiota is, what its functions are, what happens when something goes wrong with our microbiota, and what we should do to keep it in balance.
What is the gut microbiota and what are its main functions?
The gut microbiota refers to the set of microorganisms that inhabit our digestive tract, primarily the intestine. These are trillions of tiny beings—mostly bacteria, but also viruses, fungi, and archaea—that have evolved with us in a mutually beneficial relationship. In fact, they are estimated to outnumber our own cells and contribute a genetic content (microbiome) one hundred times greater than that of the human genome. In other words, we are a “superorganism” composed of the symbiosis between the human body and its microbiota.
This intestinal flora (as it is also known) begins to establish itself from birth and is shaped throughout the first years of life. In adulthood, microbiota is usually relatively stable, although unique to each individual, like a microbial fingerprint.
Key functions of the gut microbiota
Our intestinal microbiota acts as a truly forgotten organ that performs multiple essential functions :
- Aids in digestion and nutrition: Gut bacteria ferment foods that our bodies can’t digest on their own (e.g., fiber) into beneficial nutrients. They generate short-chain fatty acids like butyrate, which feed colon cells and reduce intestinal inflammation . They also synthesize important vitamins (such as vitamin K and some B vitamins) and help extract energy from food (1).
- Strengthens the intestinal barrier: The microbiota helps maintain the integrity of the intestinal mucosa. This means it helps keep the intestinal wall strong and prevents pathogens or toxins from passing into the bloodstream (1).
- Protection against pathogens: Beneficial microbes crowd out and control harmful bacteria by competing for space and nutrients. Under normal conditions, the microbiota acts as a shield that makes it difficult for disease-causing foreign microbes to colonize the gut. Therefore, a balanced microbiota helps us prevent gastrointestinal infections.
- Train and modulate the immune system: Approximately 70% of our immune system resides in the gut. Commensal bacteria “teach” our defenses to recognize dangerous microorganisms and tolerate harmless ones. This constant interaction is crucial for an adequate immune response.
- Communication with the brain (gut-brain axis): Surprisingly, the gut and brain are connected via nerves (vagus nerve) and chemicals. The microbiota produces neurotransmitters and other molecules that can influence mood and brain function. Therefore, its relationship with anxiety, depression, and other disorders is being investigated. Although much remains to be discovered, it is known that a healthy microbiota can contribute to improved mental well-being , while alterations in it have been associated with mood swings (2)
In short, the gut microbiota promotes digestion, strengthens immunity, protects us from infections, and helps keep us healthy in body and mind. It’s a key component of our biology, and when it’s functioning properly, we hardly realize it’s there, silently working for us.
We hope you find this info helpful. Next week we will explain what kind of problems can be derived from an inbalanced microbiota. Stay tuned!!