The gut microbiota is the entire collection of microorganisms—mainly bacteria, but also viruses (microbiota) and fungi (mycobiome)—living in our gut where they reproduce, communicate with each other, and with our own cells.
Microbiota and microbiome are often used interchangeably but indicate two different concepts. The term microbiota refers to the group of microorganisms that colonize human body tissues. The term microbiome, on the other hand, indicates the genetic heritage possessed by the microorganisms that make up the microbiota. Just like fingerprints, each person’s microbial “fingerprint” is unique and extremely personal. No individual has a microbiota that is the same as that of another.
This is the reason why the use of lactic acid bacteria food supplements should be custom tailored to one’s own microbiota and not just taken “blindly”.
It is estimated that the human gut microbiota can weigh up to 2 kg and that the number of bacterial cells in the body is from 2 to 10 times more than the number of human cells. The microbiota is a full-fledged organ and a life without it is, in fact, just as impossible as life without a heart, lungs, or a brain.
Diet, age and a whole series of environmental and genetic factors significantly change the quality and biodiversity index (alpha-diversity) of our microbial patrimony. On average, a person living in the western world hosts about 1,000 bacterial species. In aboriginal populations, on the other hand, there is such a wide bacterial diversity that this number can reach up to 5,000 species. Since the industrial revolution, despite its indisputable advantages, the abandonment of a true agricultural diet linked to the seasonality of the territory has resulted in a dramatic reduction in microbial diversity and the loss of nearly 4 of the 5 bacterial species that once resided in our gut.
Supporting the microbiota through a varied, balanced diet and a healthy lifestyle is essential for not wasting, but instead enriching this very important bacterial patrimony that is passed down from parents to their children.