[Structure and function of intestinal microbiota in health and disease--130 years after Theodor Escherich].

Since early life we are colonized by developing communities of microbes that dominate our body in great numbers. In the intestinal tract they constitute the largest microbial ecosystem close to our heart: our microbes inside. Recent studies have shown that these microbes, collectively termed microbiota, are essential for our health through interacting with our gut, gut-liver and gut-brain axis, and our immune system. Hence this contribution deals with these aspects and provides an overview of the structure and function of the microbiota as well as the impact on future therapies ranging from fecal transplantations to the use of a synthetic microbiome.