In conclusion, this study demonstrated that 60-day S. boulardii and SOD supplementation in obese subjects determined a significant reduction in BMI, with weight loss due to the decrease in fat mass, with preservation of fat free mass, HOMA index and uric acid, suggesting an interesting and promising role of the supplementation with S. boulardii in association with SOD in treating obesity. Here, SOD1 is linked to obesity due to melanocortin 4 receptor deficiency.