INS and obesity due to melanocortin 4 receptor deficiency: In addition, increased serum acetate levels produced by gut microbiota have reported to be associated with obesity and insulin resistance by stimulating insulin secretion with activating parasympathetic nervous system.(38) In the present study fructose intake increased visceral fat mass and insulin resistance with elevating serum acetate levels, indicating that high fructose in the diet increased production of acetate by gut microbiota.