The study was aimed at determining the effect of four different concentrations of lactic acid 0.002, 0.004, 0.006, and 0.008% on the survival rate of Lactobacillus acidophilus and Bacillus subtilis and the effect of their mixture as growth promoters in honeybee's nutrition. The best result of the survival rate of bacteria was 102.56 ± 3.21 % for the concentration 0.004%. Honeybee workers' feed consumption in the cages under study ranged from 2.17 ± 0.7 to 6.67 ± 1.53 cm3 during 17 hours. The statistical analysis of the mortality rate for workers in the cages showed no significant differences in any concentration. As for pH values of intestinal honeybee workers exhibited the highest result for the concentration 0.002% with pH 5.18 ± 0.1. It can be concluded from this study that, the mixture of Lactic acid with L. acidophilus and B. subtilis can be used as a growth promoter in bee's nutrition that causes a decrease in the intestinal pH of honeybee workers thus inhibiting the growth of pathogenic microbes.