This study investigated the effect of three carrier agents, viz. maltodextrin (MD), gum acacia (GA), and xanthan gum (XG), on three synbiotic legume-based beverages subjected to optimized spray-drying conditions. Several characteristics of the encapsulated synbiotic powders were evaluated, including moisture content, bulk, and tapped density, dissolution encapsulation efficiency, flow properties, particle density, porosity, color, and powder yield. The survivability of probiotic bacteria Lacticaseibacillus casei ATCC 335 was also observed under gastric acid, bile salts, and simulated gastrointestinal tract. The results showed that while the higher powder yield (11–23%) was shown by MD-coated beverage powders, GA-coated beverage powders showed better encapsulation efficiency (79.9–89.3%) as well as lower moisture content values (<5%). Moreover, among all the samples, GA-coated kidney bean beverage (KB) powder showed the maximum probiotic survivability (>7 log CFU/mL) in the case of gastrointestinal simulation and under gastric acid and bile juice. The scanning electron microscopy also showed the desirable particle morphology and formation of microcapsules preserving the probiotic activity. The thermal properties of GA-coated KB powder showed the peak degradation temperature as 143.44 °C, which suggested the use of appropriate drying temperatures for making stable encapsulated synbiotic powders. Thus, GA-coated KB powder holds the potential to be used as a functional food with synbiotic properties along with acceptable powder characteristics and maximum probiotic survivability.