this book, the proceedings of falk symposium 100, `gut and the liver, held in freiburg, germany, 29-31 may 1997, comprehensively reviews the physiological and pathophysiological interactions between the intestine and the liver as well as between intestinal and hepatic diseases. apart from the basic aspects of the intestinal microflora and the immune system of the gut, gastrointestinal permeability and translocation as well as the contribution of the intestine and the intestinal bacteria to the metabolism of bile acids, amino acids and drugs are discussed. in addition, experimental as well as clinical data demonstrating the significance of gut-derived bacterial toxins for the development of liver diseases and the effect of liver diseases on gastrointestinal functions are discussed. the major aim of this book, therefore, is to highlight the interactions between gut and liver at the molecular level as well as in clinical disease.