Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Nutrition, Dietetics, and Food Sciences


Korry J. Hintze


Abby D. Benninghoff


Michael Lefevre


Prior work by our research group showed that the total Western diet (TWD), a rodent diet which models the typical American diet, promoted the development of colon tumors when fed to mice. Other researchers previously showed that vancomycin, an antibiotic that changes the gut microbiome composition, causes differential changes in the severity of colon inflammation and CRC. Our goal was to determine the combined effects of feeding the TWD and vancomycin treatment on colitis and CRC, and if these factors interact. We hypothesized that vancomycin treatment would mitigate colitis and CRC in mice fed the TWD. To this end, mice were fed either a healthy diet or the TWD. Mice were also given either vancomycin in their drinking water, or plain water. Colon inflammation and tumor development was induced in mice by treating them with a gut irritant and a chemical carcinogen. Contrary to our hypothesis, mice fed the TWD and treated with vancomycin experienced more severe intestinal inflammation and had greater tumor burden compared to mice fed a standard diet. Furthermore, vancomycin treatment decreased the number of bacteria l species present in the fecal microbiome and altered the relative abundance of the taxa that were present. Rather than the diet consumed, vancomycin was the driving force in determining the bacterial community composition. Overall, these results suggest that vancomycin-induced changes to the gut microbiome may be associated with increased development of colon tumors, particularly in the context of a Western dietary pattern.



Available for download on Wednesday, May 01, 2024