Two Lactobacillus spp. harvested separately from caecum and jejunum of Assam indigenous chickens. India were characterized both as Lactobacillus reuteri and registered under GenBank, NCBI, India as Lactobacillus reuteri PIA16. Treating as individual entity, their effect on the productive performance of broiler chickens were evaluated when supplemented singly and with prebiotic, mannan oligosaccharide to the broiler diet and noted for variations between the strains. Daily broiler ration (20%) fermented daily with 20% of L. reuteri PIA16 culture at a dose of 108cfu/ml when fed to the birds, significantly (P<0.05) improved body weight gain, feed consumption and FCR were observed. The effect was further improved with addition of prebiotic (MOS). Despite the higher production cost per broiler in all the L. reuteri PIA16 fed groups, the gross profit was high when compared to control group and higher still in prebiotic added groups. It can, thus, be considered as potential probiotic agent.