Human gut microbiota/microbiome in health and diseases: a review

The human gut microbiota has received considerable interest in the recent years and our knowledge of the inhabitant species and their potential applications is increased particularly after the development of metagenomic studies. Gut microbiota is highly diverse and harboring trillions of microorganisms in human digestive system. The shaping and multiplication of gut microbiome starts at birth, while the modification of their composition depends mainly on various genetic, nutritional and environmental factors. The modification in the composition and function of the gut microbiota can change intestinal permeability, digestion and metabolism as well as immune responses. The pro inflammatory state caused by alternation of gut microbiota balance lead to the onset of many diseases ranging from gastrointestinal and metabolic conditions to immunological and neuropsychiatric diseases. In this context, the present review clarifies the role of gut microbiota in maintaining host health and investigates how nutritional and environmental factors affect the gut microbial structure and function. In addition, many therapeutic strategies of gut microbiota aimed at modulating and restoring of the intestinal ecosystem balance have been surveyed.