How Your Gut Flora Affects Your Health

Flora is a scientific term for a group of plants or bacteria that are characteristic of a particular area. It is often contrasted with the term "fauna", which is used to describe the life of animals in the same particular area. In the field of health care and medicine, the term flora is used to describe microorganisms that exist on or within the human body, such as intestinal flora or skin flora. When we talk about flora in the context of the human body, this term refers to bacteria, yeast, and other fungi.

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The intestinal flora belongs to the world of microorganisms, mainly bacteria, that inhabit our intestines. Research is increasingly focused on trying to understand the role that gut flora plays in terms of human health. Several names are used to refer to this internal population of microorganisms:

  • Intestinal bacteria
  • Intestinal flora
  • Microbiota
  • Microbiome
  • Microflora

It has become very clear that the intestinal flora plays an important role in both our health and our vulnerability to disease.

Development of

Babies are born with intestines that are considered completely or mostly sterile. As they pass through their mother's birth canal, they are exposed to microorganisms in her vagina, which are the source of the microbiome population. The microbiome is further colonized by environmental influences and the consumption of breast milk, formula, and ultimately food. These are factors that affect the microbiome of babies who are delivered by cesarean section and who do not pass through the birth canal. The composition of the intestinal flora continues to evolve throughout our lives .


Substances released during digestion affect the spread of intestinal bacteria. Stomach acid, bile acids, and pancreatic enzymes generally prevent bacteria from colonizing the stomach or early part of the small intestine. ( Bacteria overgrowth in the small intestine is a health problem in which there is an excess of bacteria in the small intestine.)

Therefore, intestinal bacteria are found to some extent in the last part of the small intestine, but in the vast majority of cases in the large intestine. It is estimated that there are more than a thousand types of germs in your body ( a 2015 study found that these microbes make up 25% to 54% of your stool). This microbial world is internally separated from your body by a single layer of colon cells, cells known as epithelial cells .


As stated above, your gut flora plays a key role in your health. The two most important functions are related to the protection of the immune system and metabolism. To carry out these important functions, an optimal prevalence of "friendly" bacteria is required. Let's take a look at each of these functions in turn:

Immune system support

Gut bacteria seem to support our immune systems in two ways. First, beneficial bacteria provide direct protection to the lining of the colon, trapping substances that are harmful to us. When this system is compromised, a leaky gut condition (leaky gut syndrome) can occur. Second, good gut bacteria work with the immune system at the lining of our intestines to fight harmful bacteria or other substances .

Beneficial metabolic effects

Our intestinal flora plays an important role in providing us with the vitamins and other nutrients that we need for our health. The microbiome also interacts with carbohydrates that have not been digested in the small intestine (such as resistant starch and FODMAPs ). This interaction provides additional nutrients, stimulates epithelial cell growth, and regulates fat storage .

Related health problems

It is now recognized that a less than optimal gut flora can contribute to health problems, both digestive and non-digestive. Health problems that currently have a direct link to an unhealthy balance of gut flora, a condition known as dysbiosis , include:

Gut flora care

Reducing stress, minimizing the use of antibiotics, and a balanced and nutritious diet (including foods that are considered prebiotics ) can improve your gut flora. Also, while its benefits are far from proven, probiotics can help and generally don't make things worse. The procedure, known as a fecal microbiota transplant , promises to improve the health of the intestinal flora in extreme cases .

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