Probiotic bacteria play a critical and functional role in clinical and nutritional applications. In the present study, the ability of various probiotics and their metabolites in the prevention and treatment of different diseases, infections and disorders was reviewed. The issues that were noticed are included: Fibrocystic, diabetes, acne, colon cancer, cardiovascular, urinary tract infections, atopic eczema syndrome, food allergies and obesity. Enhancement in using drug treatment has led to the appearance of drug-resistance concern, thus probiotics can be a suitable choice. This review focuses on the effect of probiotic bacteria and their metabolites on immune-boosting, prevention and treatment of these diseases. For this purpose, after a s...