INS and metabolic syndrome: Moreover, a 12-week wholegrain-based diet (cereal fibre: 28.9 ± 1.1 g/day) has shown to increase plasma propionate concentration compared to a refined-cereal-based diet used as control (cereal fibre: 11.8 ± 0.4 g/day), and this increase correlated with an improved insulin postprandial response in individuals with Metabolic Syndrome [26].