ETH Zurich Apr 4 2025 The issue of intestinal bacteria is a complex one. On the one hand, we are dependent on the microorganisms because they are the ones that digest the food in our intestine. On the other hand, there are also numerous pathogens present among the bacteria. Some of these pathogens can cause diarrhoea, while with others it depends on the circumstances: they can live unnoticed in the intestine for a long time, but they become dangerous if the immune system is weakened, the