WHAT ORGANISMS INHABIT THE HUMAN BODY? - ANATOMY AND PHYSIOLOGY - 2025

The organisms that inhabit the human body are bacteria, fungi, viruses and protozoa. In total, the microbiome that exists in the human body is home to more than 100 trillion microorganisms.

Both on the surface and on the inside, the human body is mined with various microscopic forms of life. In one centimeter of the epidermis, for example, there are more than 10,000 bacteria.

To these must be added the microorganisms that make life in the humid areas of the body, in the upper respiratory tract, in the digestive tract and in the intestines.

Four microorganisms that inhabit the human body

The coexistence between bacteria, fungi, parasites and viruses in the human body takes place in a symbiotic and balanced way, since some of these microorganisms complement biochemical processes within the human body.

Below is a brief description of the microorganisms that inhabit the human body:

1- Bacteria

Humans are mined by bacteria, mainly in the epidermis and in the digestive system.

Several species of staphylococci usually live on the superficial layer of the skin, given the exposure of the skin to pollutants from the outside environment.

Similarly, the body has thousands of bacteria in the gastrointestinal tract, including the mouth and throat.

These microorganisms fulfill healthy functions in the body, since they help in the breakdown, transformation and synthesis of nutrients: the body alone would not be able to absorb these nutrients.

However, under normal conditions the internal organs, the blood and the lower respiratory tract of the lungs should not contain any type of microorganism, since this would imply the presence of infections.

2- Parasites

There are three types of parasites that can live within the human body:

- Protozoa

They reproduce easily inside humans. The transmission of protozoa that live in the human intestine is carried out by the fecal-oral route, due to unsanitary conditions and / or the consumption of contaminated water or food.

Instead, protozoa that develop in the blood or soft tissues are transmitted through a transmitting agent, such as mosquitoes.

- Helminths

They are small worms that make life inside the human intestines, absorbing most of the nutrients. They do not reproduce within the human body.

- Ectoparasites

Refers to lice, mites, fleas and ticks. These organisms are transmitters of a wide variety of infectious agents.

3- Mushrooms

Fungi are also part of the human microbiome. They are present on the skin, especially the scalp and feet, including the heels and nails.

There is also a moderate amount of fungus on the hands, as well as on the nose and in the section just behind the ear.

4- Viruses

Viruses do not usually disappear from the human body; they generally attack once and remain incubating in the body for several years, or even permanently.

Some of the most common viruses that affect humans are: the influenza virus (flu), cold sores, chickenpox and hepatitis, among others.

References

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