Plasma samples will be collected from all blood samples from OGTTs and week 6 blood sample. Plasma glucose and lipid profiles (total cholesterol, HDL, LDL and triglycerides) will be measured by KONI analysis at the University of Aberdeen. Insulin will be measured by ELISA by researchers. All the plasma samples which are taken before and after taking the prebiotic supplement also be analysed for GLP-1, GIP, c-peptide and glucagon analysis by luminex assay.