In this study, the effect of bile acid concentration on the gut microbiome of squirrel ceca was studied. During the periods of hibernation in which an animal is fasting and has decreased metabolic activity, bile acid concentration changes significantly. Gut microbiome composition can change due to various factors, and changes in bile acid concentration may be one of those influencing factors. Agar plates were made with a variety of different concentrations of bile acids. Cecal content samples from squirrels before and during torpor were inoculated onto the plates. The results of the fall samples showed significant growth inhibition with increased bile acid concentration. The results for the torpor samples were inconclusive. The relationship between the gut microbiome and bile acids can be further explored by continued testing with more samples and identification of the microbial species.