Scope The objective of the present study is to evaluate the effects of milk powder co-supplemented with inulin and resistant dextrin (MPCIR) on elderly patients with type 2 diabetes mellitus (T2DM). Methods and results A randomized, double-blind, placebo-controlled clinical trial is carried out among elderly T2DM patients. The subjects recruited from the community are randomly assigned to either the MPCIR group or placebo group for 12 weeks intervention. Each group receives 45 g milk powder with or without inulin and resistant dextrin. Anthropometric and metabolic variables are measured. For the MPCIR group, systolic blood pressure (BP) and diastolic BP are reduced significantly by 5.45 and 4.56 mm Hg (p < 0.001, vs placebo group), respectively. Compared with the placebo group, the fasting and 2-h postprandial plasma glucose levels, glycosylated serum protein, and insulin resistance index of the MPCIR group are significantly decreased by 0.96 mmol L-1, 1.47 mmol L-1, 16.33 mu mol L-1, and 0.65 respectively (p < 0.001). The MPCIR group shows an increase by 7.09 mu IU mL(-1) and 20.43 in 2-h postprandial insulin (p = 0.016) and beta-cell function index (p < 0.001), respectively. Conclusion MPCIR supplementation helps to improve glycemic control, insulin resistance, and blood pressure.