Just think. A huge number of microorganisms live inside our body, without which life itself would be impossible. Our intestines alone contain about 50 trillion (!!!) bacteria. This is about 1.3 times more than all the cells in our own body. The mass of human intestinal microorganisms reaches 3 kg. Bacteria live in almost all of our organs and are involved in a number of different processes.
And how our microorganism works depends not only on digestion, but also on the immune system, metabolism, skin condition and even mood.