Introduction to the Human Microbiota

The human body hosts a vast number of microbes, primarily bacteria, that inhabit many regions of the body, including the skin, mouth, gut, and urogenital tract.

Together, these microbes form the human microbiota, a community that supports key functions in the body.

A portion of these microbes makes up the resident microbiota which are long-term, stable populations, while transient microbiota are present only for short durations.

Microbial colonization begins at birth. As a person grows, factors such as diet, age, environment, and antibiotic use influence the diversity and stability of microbial communities.

Also, temperature, pH, oxygen levels, and body secretions affect microbial growth.

Through a process known as microbial antagonism, the normal microbiota can protect the host by physically occupying binding sites and consuming nutrients, so they outcompete invading pathogens.

For example, microorganisms in the gut promote health by synthesizing vitamins and suppressing pathogens through the production of bacteriocins.