The Effect of Sucralose on the Inhibition of Three Bacteria Species that Inhabit the Human Gut

The Effect of Sucralose on the Inhibition of Three Bacteria Species that Inhabit the Human Gut

The purpose of this experiment is to examine the proposed bacteriostatic (growth-inhibition) effect of sucralose, a minimally metabolized, non-nutritive, and non-caloric sweetener on three species of bacteria commonly found in the human gut. Sucralose has been shown to inhibit the growth of environmental bacteria likely due to the inhibition of the invertase enzyme, which is involved in the breakdown of sucrose. This study attempts to replicate this finding with bacterial species associated with the human gut microbiome and to test if the bacteria are still susceptible to growth inhibition by sucralose while in a monosaccharide rich environment, such as with the addition of dextrose (D-glucose). These results can be relevant to the study of human gut microbiota because sucralose has been suggested to cause changes in the bacterial species composition found in intestines, a monosaccharide rich environment. Three species were used as test organisms (Escherichia coli, Enterobacter aerogenes, and Lactobacillus acidophilus). Initially, each species of bacteria was grown in LB broth with dextrose, sucrose with dextrose, sucralose with dextrose, and sucralose alone. Cultures were incubated for 48 hours and diluted to concentrations of 10-7 and 10-8 in distilled water via a serial dilution. The diluted samples were plated on TSA media and incubated for 24 hours. Bacterial growth on the plates was recorded by counting the number of colonies and ranking the amount of growth on each treatment using a 1 to 4 rank scale.