Background: Obesity, the most common health problem, can result in the incidence of many chronic diseases. genetic and environmental factors can affect its incidence. Differences in the population of gut microbiota in lean and obese subjects and interaction between them, has led to a field of investigation about the effects of intestinal microbiota in the obesity occurrence. In the other hand, the use of functional foods has been shown positive effects in the prevention of obesity. This study was aimed to assess the differences between gut microbiota in obese and normal people, their roles in energy homeostasis and the mechanisms of probiotics and prebiotics in the management of obesity.

Materials and Methods: All articles indexed in the valid scientific data bases published between 2000 And 2014 were Searched and reviewed using probiotics, prebiotics, obesity and gut microbiota as key words and results were examined.

Results: A group of gut microbiota facilitates energy extraction from the diet that results in fat storage in adipose tissues. bacteroidetes as a residing bacterial in the gut is in fewer amount, inversely, firmicutes as another residing bacterial is in higher amount in obese people, and it changed in lean individuals, inversely. Differences in the extraction of energy in subjects were attributed to differences in the composition in gut microbiota. archaea ‌species that resident in the gut involved in energy homeostasis through increasing the ability of fermentation, electron production and removing the energy. In addition to, the probiotic and prebiotic supplements have roles in the prevention of obesity via stimulating the growth of beneficial bacteria, production of short chain fatty acids, modulating the secretion of hormones involved in energy homeostasis.

Conclusion: Further studies are needed to identify the specific probiotic bacteria and other effective functional foods in management of obesity.