Background: A new sweetener with the commercial name of Lacritose has been recently produced, which is a combination of four simple sugars (lactose, fructose, sucrose, erythritol), with specific ingredients and percentages. This study aimed to assess glycemic response and short term gastrointestinal reactions in type 2 diabetic patients. Methods: In this triple-blind randomized clinical trial, 30 diabetic patients referred to Yazd Diabetes Research Center in 2018 were included. After collecting the primary data, they were assigned into three groups, including sucrose consumers as the control group, sucrose-lactose, and lacritose as the groups of consumers group. They were followed for two weeks, and fasting blood glucose (FBG), 2-hour postprandial test (2HPP), fructose amine, SGOT, SGPT, urea, creatinine, and insulin resistance index (HOMA-IR) were assessed. Results: In lacritose consumers, significant reductions were seen in FBG and 2HPP (P < 0.001 and P = 0.05, respectively), although changes among the groups were not significant. In sucrose-lacritose consumers, FBG and cholesterol levels decreased (P = 0.04 and P = 0.03, respectively). In sucrose consumers, no reduction was seen. HOMA-IR did not significantly decrease, but intergroup changes were obvious. Conclusion: The lacritose effects on FBG and 2HPP were significantly evident, but the other metabolic indices did not show any significant change.