Date of Award

Fall 12-2015

Degree Type

Honors College Thesis


Biological Sciences

First Advisor

Shiao Wang

Advisor Department

Biological Sciences


Gut microbiota is a community of bacteria that live in the digestive track of a host. These microbes assist in the breakdown of indigestible materials as food passes through the alimentary canal. Metabolites from bacteria may play a role cell to cell communication with their host and thus gut microbiota may affect the diet preference of the animal host. Southern Leopard frogs (Rana sphenocephala) and Green Tree frogs (Hyla cinerea) were used as focal species to test whether gut microbiota affect their diet preference. Three groups of tadpoles were tested. The control group was fed a commercial diet called Frog Brittle which contains essential vitamins and nutrients for the tadpole. The second diet contained Frog Brittle with the addition of Timothy grass which has high cellulose content. The third diet contained Frog Brittle with the addition of chitin. Both cellulose and chitin are generally considered indigestible by animals. Therefore, my hypothesis is that gut microbes that benefit from cellulose or chitin would produce chemical cues that influence diet choice among tadpoles with gut microbiota adapted to diets containing either Timothy grass or chitin.

The gut microbiota was analyzed by amplifying the V3 region of the 16S rDNA using DNA extracted from tadpole feces. The amplified DNA was analyzed using Denaturing Gradient Gel Electrophoresis (DGGE) and/or High Resolution Melt (HRM) Analysis. Diet preference tests were conducted using diets containing fluorescent microspheres as a tracer.

My results using both DGGE and HRM showed that diet composition affected the gut microbiota in tadpoles with certain groups of bacteria being more dominant in a diet dependent manner. However, diet preferences ranged from 0.6443-0.8888 and were insufficient to support the hypothesis that gut microbiota effects diet preference.

Included in

Biology Commons