Role of multi-strain probiotic formulations in the management of type 2 diabetes mellitus (T2DM) has rarely been reported. In the present study, the effects of the probiotic formulation, UB0316 (L. salivarius UBLS22, L. casei UBLC42, L. plantarum UBLP40, L. acidophilus UBLA34, B. breve UBBr01, B. coagulans Unique IS2, 5 billion CFU each and fructo-oligosaccharides, 100 mg) in patients with T2DM were assessed.A total of 79 eligible subjects (18-65 years, on stable metformin therapy) were randomly assigned to receive UB0316 or placebo, twice-a-day for 12 weeks. The primary endpoint was change in glycated hemoglobin (HbA1c), secondary were assessment of blood glucose levels, HOMA-IR (homeostatic model assessment of insulin resistance), insulin, body weight, and blood lipids. Quality of life, vital signs, physical investigations, safety and Physician/Subject's Global assessment were also evaluated.Twelve week multi-strain probiotic (UB0316) supplementation significantly reduced HbA1c (7.70 ± 0.79%; p = 0.0023) and weight (67.00 ± 8.82 kg; p < 0.001) as compared to placebo (HbA1c: 8.30 ± 1.35%; weight: 67.60 ± 9.46 kg). The changes recorded in fasting blood glucose (FBG), HOMA-IR, insulin, TC, TG, HDL, and LDL levels were however not significantly altered as compared to placebo. No severe adverse events, abnormal vital and physical signs were reported. The quality of life of T2DM was significantly improved.UB0316 significantly improved glycemic control as indicated by the decrease in HbA1c levels. There was also a significant decrease in weight in the probiotic treated subjects as compared to placebo.