“We often refer to good bacteria called ‘lactic acid bacteria’ when talking about immunity,” says a fermentation expert. “With the immune system, the role of good bacteria is to attack harmful ones. So the presence of these good lactic acid bacteria in the intestinal tract helps ‘train’ the immune system to attack any bad bacteria as soon as they appear.” They add that a daily intake of good bacteria is necessary to regulate the immune system, so it’s always prepared to fight harmful bacteria. It just goes to show that our eating habits are genuinely essential.