Probiotics are the live microbial food supplements which improves the microbial balance and enhanced rapid cellular growth and development. Commercial probiotics viz., Lactobacillus rhamnosus, Saccharomyces boulardii and Bifidobacterium longum with six different concentrations (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 %) were used to fortify the mulberry leaves, fed to silkworm and studied its impact on gut population, enzymatic activity and economic parameters. Among the different concentrations, 3 % recorded maximum bacterial population, amylase activity and improved economic parameters in all the probiotics treated CSR 2 larvae. Among the three probiotics, Bifidobacterium longum @ 3 % recorded highest gut population of 3.11 x 107 cfu/ml and 3.56 x 107 cfu/ml in fourth and fifth instar larvae. amylase activity (64.79 mg/g) and economic parameters like cocoon weight (1.52 g), Pupal weight (1.20g), shell weight (0.32 g) cocoon weight and shell ratio (21.05 %) respectively. The present findings of the study strongly suggested that fortification of probiotics to silkworm through mulberry feed enhances gut microbes, enzyme activity thereby economic parameters of silkworm.