Author(s): Jessica Oram, Tom Vo
Mentor(s): Lauren Brooks
Institution UVU
The composition of gut and oral microbiomes has been demonstrated to have significant impacts on an individual’s overall health. Understanding what influences these microbial communities can help inform strategies for treatment in individuals who do not have a healthy microbiome. Observational studies have determined that consuming artificial sweeteners influences the abundance of numerous organisms. However, to date, no studies have examined how these sweeteners affect the growth rate of individual species. This study investigates the effects of various sweeteners on the growth rates of selected oral and gut bacteria. Bacteria were selected based on relevance for oral and gut health, their ability to be readily cultured in the lab, and ready access through BEI resources (a subset of the American Type Culture Collection, or ATCC). The selected bacteria were cultured in their media recommended from ATCC to confirm viability as determined by Optical Density (OD600) readings after 24-48 hours. Positive bacteria were tested for growth in minimal culture media containing glucose as its primary sugar source (E3 media). Bacteria were then grown in the E3 media containing artificial sweeteners in place of glucose in a 24-well plate and monitored using a plate reader set to take OD600 readings every 5 minutes for 24 hours. The time period of exponential growth was assessed visually for each well, and the growth rate was calculated based on the slope of the line during this time period. Statistical analyses were conducted to compare the bacterial growth in E3 containing artificial sweeteners to negative controls (i.e., determine if any growth occurred) and to their growth in E3 containing glucose. Many bacteria strains were able to grow in a variety of artificial sweeteners. However, we typically observed lower growth rates for bacterial strains cultured with artificial sweeteners as compared to those cultured with glucose. The severity of these impacts differed between sugars and the bacterial strain being examined Differences observed in oral, and gut microbial communities are likely to be caused by altered growth rates of at least some strains of bacteria. These results reflect multiple health applications of artificial sugars which could compromise a healthy gut microbiome. However, a positive benefit for controlling unwanted plaque causing bacteria in the oral environment. Future work needs to be done to expand the strains tested and complete this work in more realistic model systems that incorporate multiple species and environmental conditions that better reflect the system of interest.