As calorie-consciousness becomes a worldwide phenomenon, demand for low-calorie sweeteners is increasing. Compared to other sugars, the reduced calorific value of mannitol (1.6 kilocalories per gram) finds its application as a sweetener in low-calorie foods. The present study was conducted to develop low-calorie yoghurt by adding lactic acid bacteria (LAB) having significant mannitol production potential. Leuconostoc pseudomesenteroides IMAU:11666 was incorporated to standard yoghurt culture as adjunct culture. As mannitol is a food-grade sweetener with Food and Drug Administration (FDA) endorsement, the newly identified LAB strain can be used to develop low-calorie dairy products with beneficial effects. Side effects of other artificial sweeteners can also be reduced. Significantly high (p≤0.05) mannitol content was observed in functional yoghurt samples T1 (12.27 ± 0.18 g/l) and T2 (14.13 ± 0.30 g/l) with Leuconostoc pseudomesenteroides when compared to control samples. The calorific value obtained for yoghurt samples viz., C1, C2, T1, and T2 (86, 95, 98, and 92 kcal/100g, respectively) was less than control yoghurt C (99 kcal/100 gm). Microbial and chemical quality parameters of the functional yoghurt were in the safe and acceptable zone. On sensory evaluation of yoghurt samples, significantly higher overall and flavor scores were observed for sample T2 with Leuconostoc pseudomesenteroides.