Michael Siegel

Background: The gut microbiome communicates bidirectionally with the brain, linking the gut to psychological phenomena such as stress, depression and anxiety. Probiotics, or ingestible supplements containing billions of mutualistic bacteria, have demonstrated the mechanistic potential to influence mood. The present study hypothesized reductions in stress, anxiety and depression symptoms following an acute, one week dosing period of B. longum intake. Methods: The efficacy of a one-week period of orally administered B. longum was tested utilizing a double-blind experimental design. Two groups were randomly chosen and tasked with responding to the Perceived Stress Scale (PSS), the Center for Epidemiological Studies Depression scale (CES-D), and the State-trait Anxiety Inventory (STAI Y2 form) to assess for differences before and after one-week intervention. Results: No significant reduction in symptoms between groups over the one-week period was found. Conclusions: These findings suggest that 7-days of B. longum does not reduce perceived stress, depressive symptoms, and anxiety in generally healthy young adults.