[Interaction between humans and intestinal bacteria as a determinant for intestinal health : intestinal microbiome and inflammatory bowel diseases].

Recent scientific results underline the importance of the intestinal microbiome, the totality of all intestinal microbes and their genes, for the health of the host organism. The intestinal microbiome can therefore be considered as a kind of "external organ". It has been shown that the intestinal microbiota is a complex and dynamic ecosystem that influences host immunity and metabolism beyond the intestine. The composition and functionality of the intestinal microbiota is of major importance for the development and maintenance of intestinal functions. Inflammatory bowel diseases (IBD) are characterized by dysregulated interactions between the host and its microbiota.The present contribution summarizes current knowledge of the composition and development of the intestinal microbiome and gives an overview of the bidirectional interaction between host and microbiota. The contribution informs about insights regarding the role of the intestinal microbiota in IBD and finally discusses the protective potential of microbial therapies in the context of IBD.