Malnutrition through excessive food consumption is a worldwide pandemic. Changes in lifestyle, diet and physical activity have resulted in an exponential increase in the number of obese people around the world. Multiple factors influence the development of this disease, and recently it has been suggested that gut microbiota (GM) plays an important role in nutrient absorption and energy regulation of individuals, thus affecting their nutritional status. It has been proven that gut microbiota is different in individuals with a normal nutritional status compared to those who are obese. Therefore, to study bacterial populations that make up the microbiota and to understand how prebiotics and probiotics affect the increase of these bacteria has become a promising alternative to treat obesity. This chapter looks at defining the established relationship between probiotics, prebiotics and gut microbiota that develop in obese people and people of normal weight, with the aim of providing future dietary recommendations to treat this medical condition.