Comparing the Effects of Artificial Sweeteners and Sugar on the Growth Rate of Lactobacillus Acidophilus

Artificial sweeteners have become a popular dieting aid, but their possible side effects are not fully understood. Artificial sweeteners have recently been linked to increased populations of Firmicutes, gut bacteria that increase fat absorption. An in vitro study was conducted to determine if artificial sweeteners directly affect the growth of Lactobacillus acidophilus, a type of Firmicutes. Two artificial sweeteners were tested, sucralose (Splenda) and aspartame (Equal), against traditional sugar. These treatments were added to tomato juice agar. A milk broth was inoculated with Lactobacillus and grown for 24 hours at 37 degrees Celsius. Each dish, prepped with agar, was then inoculated with 0.5 ml of the broth and incubated for 24 hours. Both positive and negative controls were included in the experiment. Percent coverage for each dish was determined. An ANOVA was utilized to analyze the data and returned a P-value of 0.004. Because this value of below the alpha level 0.05, two sample t-tests were also run. Sugar and Splenda as well as Equal and Splenda were found to have significantly different means. The average percent coverage for the artificial sweeteners was similar to that of sugar and greater than the average for the positive control. This suggests that artificial sweeteners increase the growth of Lactobacillus similarly to sugar, resulting in increased fat absorption and likely contributing to obesity and its associated health risks.

Research Conducted By:

Bailey Abney
Fraser High School

Brendan Kelley
Fraser High School