Obesity is defined as abnormal lipid accumulation and hypertrophy of adipose tissue. The main reason is due to the imbalance between consumed and spent calories. Therefore, obesity is an important risk factor for morbidity and mortality in many societies. In 2013, 36.9% of men and 29.8% of women among adults were considered overweight or obese. Additionally, obesity is known as the most common nutritional disorder in dogs and cats. The number of overweight or obese individuals worldwide continues to increase. Obesity generally occurs as a result of factors such as genetic factors, eating habits or lack of physical activity. However, in addition to these factors, it is reported that the intestinal microbiota is also effective. The gut microbiota is identified as a potential factor in the pathophysiology of obesity-related metabolic disorders. The term "probiotic" first appeared in 1974. Probiotics are defined as "live microorganisms that provide beneficial health effects on the host when administered in sufficient amounts." These functional properties include suppression of pathogenic infection, synthesis of essential vitamins, improvement of the immune system and regulation of the physiological process. Probiotics improve overall health, bowel function and digestion, being increasingly included in commercial dairy products to meet consumer demand for healthy food. Modulation of the intestinal microbiota and probiotic treatment may be important strategies in predictive, preventive and personalized medicine to prevent the development of obesity and metabolic syndrome. Probiotics are considered a potential treatment for obesity, as they help maintain balance in the composition of the gut microbiota. Probiotics can improve host metabolism, reduce uremic toxicity, reduce pro-inflammatory factor levels, by protecting intestinal epithelial barrier function, competing with pathogens for nutrients, and regulating the host immune response. In conclusion; It is well known that the intestinal microbiota plays an important role in regulating metabolism in the organism. The positive interaction of the intestinal microbiota with the host physiology through metabolite production may provide a new approach in the prevention and treatment of metabolic disorders. Probiotics as an adjunct to patient treatments should be the focus of future research.