Synbiotics are a mixture of probiotics (live microbes) and prebiotics (nutrients for intestinal microbiota: soluble fibers, polyphenols and polyunsaturated fatty acids) that are now being considered important tools to help in maintaining animals in good health. Achieving adequate efficiency of the synbiotic products depends on maintaining probiotic survival and prebiotic stability against processing, storage and gastrointestinal conditions. The development of encapsulation technique facilitates the protection of live microorganism as well as the controlled and sustained release of bioactive molecules. In this study, a synbiotic consists of Saccharomyces cerevisiae yeast (SCY) and Moringa oleifera leaf extract (MOLE) encapsulated or not with alginate was fabricated to be used as a dietary supplement for growing rabbits. Sixty-four, 40 days old, growing rabbits were equally allocated into four groups and receiving per each kg diet: non-capsulated 11×10¹² SCY + 0.15g MOLE (NCS), encapsulated 5.5×10¹² SCY + 0.075g MOLE (LCS) encapsulated 11×10¹² SCY + 0.15g MOLE (HCS), or not (control). The treatments continued for six conductive weeks, from day 40 of age to day 82 of age. During the experimental period, growth performance variables including body weight (BW), feed consumption, BW gain, and feed conversion ratio were weekly recorded. At the end of the treatment, day 82 of age, blood samples and intestinal and cecal samples were individually collected from six randomly selected rabbits. Also, in vitro gastrointestinal system simulation was used to test the survival of the yeast cells through the gastrointestinal tract. Results revealed that the encapsulation process significantly improved yeast survival against gastric and intestinal digestion. Compared to the control, NCS and LCS treatments, the HCS treatment increased numbers of intestinal and cecal yeast cells (P<0.05) and lactobacillus bacteria (P=0.062) and decreased number of salmonella (P<0.05) and coliform (P=0.08) bacteria. Rabbits treated with HCS had the highest (P<0.05) phagocytic activity, lysosomal activity, and serum concentrations of IgE, and lowest malondialdehyde compared to the control, NCS and LCS treatments. The HCS treatment improved significantly body weight gain, feed conversion compared to control treatment, while the NCS and LCS treatments showed intermediate values. In conclusion, the encapsulation process improved the efficiency of innovative synbiotic. The high dose of encapsulated synbiotic adjusted gut microflora constitutes and posted immunity and growth performance of rabbits during fattening period.