The prevalence of T2DM continues to increase along the years. Probiotics and vitamin D have antidiabetic effects and a synergism between them is evident. Fermented milk such as dadih is a great source of probiotics, specifically lactic acid bacteria (LAB). Probiotics are involved in the formation of short-chainfattyacids (SCFA) which canincrease insulin production and improve Homeostasis Model Assessment-Insulin Resistance (HOMA-IR). The objective of this study was to investigatethe effect of vitamin D-3-fortified dadih on caecum SCFA concentration and HOMA-IR of T2DM-induced \Nistarrats. A total of thirty rats were randomly split into five-groups:four diabetic groups (C2, T1, T2, and T-3) and one healthy control group (C1). Intervention groups were either given vitamin D-3 (T1), unfortified dadih (T2), or vitamin D-3-enriched dadih (T-3). Concentration of SCFA, glucose, and insulin were measured by gas chromatography, GOD-POD, and ELISA, respectively. T-3 group showed significantly lower fasting blood glucose and higher insulin than T1 or T2 at post-intervention. The HOMA-IR index at the end of intervention indicated that T-3 was significantly different from T1. Total caecum SCFA and butyrate concentrations were significantly higher in T-3 than T1 or T2. The HOMA-IR had an inverse correlation with totalcaecum SCFA (r=-0.600, p=0.001) and butyrate concentration (r= -0.692, p=0.000). The decreased insulin resistance might be partially attributed to totalcaecum SCFA and butyrate concentrations. In conclusion, vitamin D-3-fortified dadih had better efficacy in improving glycemicstatus, insulin, and SCFAconcentration, leading to improved insulin resistance in T2DM rats.