Effect of saccharin on growth and acid production of glucose-grown pathogenic and oral bacteria.

Growth and acid production of glucose-grown Gram-positive and Gram-negative rods as well as cocci from the human oral cavity were studied in the presence of 0.02 to 20.00 mg/ml sodium saccharin. All Gram-positive rods, i.e. Actinomyces viscosus, Lactobacillus acidophilus, Bacillus subtilis and Corynebacterium diphtheriae, and Gram-positive cocci, i.e. Streptococcus spp, Staphylococcus aureus and Micrococcus luteus, were significantly inhibited by saccharin, especially at the higher concentrations. While Gram-negative cocci, i.e. Veillonella sp and Neisseria sicca were strongly inhibited by all tested saccharin concentrations, Gram-negative rods, i.e. the enterics and Acinetobacter sp, exhibited little if any inhibition. Saccharin caused a significant reduction in fermentative acid production congruent with observed growth.