The gut microflora and its variety of roles in health and disease

Abstract

The intestinal microbiota is a complex community of microorganisms that colonizes the gastrointestinal tract. The composition of the intestinal microbiota and the number of microorganisms differ in dependency of the local environmental conditions. The intestinal microbiota has an important impact on the development of the intestinal architecture and function, it influences the development of the gut-associated immune system, and epithelial cell functions. One of the most important functions of the intestinal microbiota is the prevention of bacterial overgrowth and susceptibility to infection with enteropathogenic organisms. Additionally, the intestinale microbiota plays a crucial role in the development of the systemic immunity and has an important influence on the host nutrition and metabolism. However, in genetically predisposed hosts, the intestinal microbiota is involved in the pathophysiology of inflammatory bowel diseases and pouchitis. Additionally, recent studies suggest that there might be an inflammation triggering effect of the intestinal microbiota in necrotizing enterocolitis. Here, we give an overview of the intestinal microbiota and its variety of roles in health and disease.