The gut microbiota or gut flora is the set of different bacteria that live in your digestive tract. Research has shown that, in addition to contributing to the digestive and defence functions of the digestive tract, it plays a major role in the nutritional status and health of people. Health problems, whether digestive or extradigestive, such as obesity or type II diabetes, lead to significant changes in the gut flora, which is known as dysbiosis. Obesity is influenced by the interaction of various factors: genetic, environmental (diet and physical activity), cultural and social. Nowadays, the gut microbiota is considered one more factor among those that have an effect on obesity and metabolic disorders. It has been seen that the microbiota of obese people is different from that of healthy people and behaves differently, making it easier for obesity to continue.