Combination of 10 selected bacterial strains A healthy immune system plays a vital role in health and well-being. This includes maintaining healthy mucous membranes, such as the intestinal lining. With a surface area of ​​approximately 400 m², the intestine is the largest organ in the human body. The intestinal flora of the digestive tract comprises billions of microorganisms. The gastrointestinal tract has a mucous membrane with a very large surface area, which is essential for nutrient absorption. The vitamin B2 contained in the Doppelherz system contributes to the maintenance of mucous membranes, such as the intestinal lining. Vitamin B2 also contributes to maintaining normal energy metabolism and reducing tiredness and fatigue. Vitamin C supports the normal function of the immune system and helps protect cells from oxidative stress.