Key functions of the gut microbiota:

Humans have a long history of symbiotic interactions with bacteria. We have coevolved with our microbiota over thousands of years, to form a complex and mutually beneficial relationship. Indeed, the gut microbiota performs functions that our human cells are not able to.

Defence:

Protection against pathogens by:
  • inhibiting their growth;
  • competing with pathogens: the gut microbiota consumes available nutrients and inhabits the available niches, leaving less nutrients and space for pathogens;
  • producing bacteriocins, compounds that inhibit the growth of potentially pathogenic microbes.
Removal of toxic compounds.

Nutrition:

Fermentation of food components that are not digested by human enzymes. This fermentation leads to the production of compounds such as short-chain fatty acids (SCFAs). These SCFAs are beneficial compounds, as they are the main source of nutrients of our intestinal cells. SCFAs, by interacting with human cell receptors, are also a key regulator of human physiology and metabolism.
Synthesis of essential vitamins (vitamin K and B).
Modification of bile acids into metabolites that are able to influence human physiology and metabolism.
Increase of the absorption of dietary minerals (magnesium, calcium and iron).

Structure:

Strengthening of the intestinal barrier.
Training and modulation of the immune system.