Without a doubt: 70-80% of your immune cells reside in the gut. The microbiome is the "trainer" of your defenses.
From the moment we are born, bacteria teach the immune system to differentiate between what is a threat (viruses, pathogenic bacteria) and what is harmless (food, your own cells). A healthy microbiome keeps the immune cells in a state of "calm alert". If the microbiome is damaged, the immune system can become hyperreactive (causing allergies or autoimmune diseases) or too weak (leaving you vulnerable to infections). Understanding your microbial balance with Vivabioma is, in essence, understanding the state of your protective shield.