The gut is home to trillions of microbes, including bacteria, fungi, and viruses, collectively known as the gut microbiome. These microorganisms play essential roles in digestion, metabolism, and overall health. But perhaps their most critical function lies in how they interact with the immune system.
Around 70% of the body’s immune cells are located in the gut-associated lymphoid tissue (GALT), where immune responses are initiated and regulated. The microbiome acts as a constant trainer for these immune cells, teaching them how to distinguish between harmful invaders and beneficial or neutral substances. This helps prevent autoimmune conditions, where the immune system mistakenly attacks the body, as well as hyperinflammation, a common feature of many chronic diseases.