Faculty Mentor(s)

Dr. Gerald Griffin, Biology and Psychology

Document Type


Event Date



The composition of gut microbiota has direct impacts on neural structure, neurochemistry, and behavior. Specifically, the gut microbiota has been shown to modulate anxiety-like behaviors. In addition, administering prebiotics, compounds that promote the growth of commensal bacteria, has been demonstrated to reduce anxiety and anxiety-related behaviors. However, this effect has yet to be tested in older animals despite anxiety being implicated as a most common disorder in adult populations. Therefore, this study seeks to fill this knowledge gap by investigating the link between prebiotic interventions and anxiety-like behaviors in aged populations. It was hypothesized that older rats treated with the prebiotic fructooligosaccharide (FOS) would display an increase in exploratory behaviors, correlating to a decrease in anxiety, compared to the controls. Behavioral assays such as the open field test (OFT), elevated plus maze (EPM), and a social anxiety (SA) test were conducted. Results demonstrate moderate evidence that rats administered FOS had increased exploration in the center zone of the OFT. This finding suggests that FOS helps to modulate behavior in aged animals. With moderate evidence for increased exploration as evidence for decreased anxiety in FOS treated animals, this study provides a platform for further investigation of the role of modulating gut microbiota in older animals. Investigating the effects of senescence versus prebiotic treatment of the rats in this cohort was dampened by the limitations of the precedent of behavioral assays utilized on smaller, younger animals. As a result, this study calls for a widening of behavioral assay parameters to allow for effective data collection in an aging population.