In recent years, the importance of the microflora has inspired a great deal of research based on the tools of modern molecular biology, microbiology and medicine. Moreover, the old idea of positively modulating an unbalanced microflora or inducing beneficial effects by administering selected, live microorganisms has seen a resurgence of interest with the development of the concept of 'probiotic' microorganisms. The purpose of this profoundly multidisciplinary volume is to provide a comprehensive up-to-date review of what is known about the gut microflora and its impact on disgestive physiology and pathology for all those interested in this fascinating subject.