This section aims at getting to better know our microscopic life partners.

Thorough the vast scientific literature, books, websites, etc on this subject, the terms microbiota and microbiome are often used interchangeable. Here, for the shake of clarity, I will be using microbiota to refer to a community of microorganisms inhabiting a particular site in our bodies, and microbiome to the collection of all the genes possessed by the microbiota.

So, this section revises the seeding and establishment of the microbiota in early life, as well as its evolution through life.

It also describes what is known about “the holobiont ecosystem”: this is, the composition and distribution of the microbiota on and inside our human bodies.

For a starter, here are a few quick facts about the microbiota/microbiome:

  • You may have heard the saying that we are 90% microbe and only 10% human… Well, it seems that the human part of us has regained some ground in the holobiont ecosystem. According to new research, the microbe-human balance is about 50-50. Draw.
  • The microbiota is comprised of different types of microbes: bacteria, archaea, viruses, protists and fungi.
  • Of all these groups of microbes, bacteria is by far the most abundant.
  • You have different species of invisible inhabitants on different sites of your body.
  • The most populous site of your body is your gut, especially your colon.
  • You acquired the majority of your microbiota during birth and it matured during your first 3 years of life.
  • A newborn has similar microbial communities across all body sites.
  • Your microbiota changes with age regardless of other factors.