The 4 drinks i.e. sweetened plain milk (SPM), functional drink (FD), rose flavored drink (RFD) and marigold flavored drink (MFD) were cultured with three activated probiotic cultures i.e. Lactobacillus acidophilus NCDC14 (1%), L. rhamnosus NCDC347 (5%) and L. casei NCDC297 (5%). The cultured samples were incubated at 37 °C for 3, 6, 9 and 12 h, respectively. The incubation time was optimized on the basis of total soluble solids, pH, acidity, probiotic count (log CFU/mL) and sensory parameters. Results revealed that RFD cultured with L. acidophilus, incubated for 6 h had the most desirable sensory properties. The final selected drink had an acidity of 0.65%, pH of 4.37 and probiotic count of 6.38 log CFU/mL. Dietary fiber and β-glucan had non-significant effect of fermentation while the cholesterol content was reduced below detection limit. A decrease in total phenols and increase in antioxidant activity was also observed. The synbiotic drink had a mean sensory score of 87.71/100 on a composite sensory scale. The product showed best before life of 15 days on refrigerated storage. This product has all the goodness of probiotics, millets, oat, milk and flowers and hence has potential to be marketed as health food. © 2020 Elsevier Ltd