Sulphate-bicarbonate-calcium Water, Body Weight and Gut Microbiota

Overweight and obese patients will be recruited and randomly assigned to two groups of intervention. To the first group \[sulphate-bicarbonate-calcium water and low-calorie diet (SW-D)\] will be administered "Acqua Santa di Chianciano"®, associated to a personalized low calorie diet, while the second group \[tap water and low-calorie diet (TW-D)\] will follow the personalized low calorie diet but will be asked to drink the same quantity of tap water, over a 4 week period. Stool samples will be collected and analyzed for changes in gut microbiota composition. Patients' body weight will be recorded at the beginning and at the end of the study.