Segmented Filamentous Bacteria (SFB) are commensal gut microbes that can modulate Th17 and Treg balance in the gut and are well known in disease states such as Irritable Bowel Syndrome (IBS). In studies led by Dr. Griggs, as part of our continued efforts to uncover the role for microflora and metabolite influence on cognition and behavior, we utilized a cohort of SFB positive and SFB negative mice in a series of behavioral tests where we found that SFB can increase anxiety and depressive behaviors. We then probed mouse cortex tissue and found that the IL-17 pathway, involved in regulation of Th17/Treg cells is upregulated due to SFB presence within the gut.