Berries, Bugs, and the Blues

This study is an ancillary project to a currently funded randomized, placebo-controlled 12-week intervention in older, sedentary adults with depressive symptoms (IRB# Pro00064749). This specific project proposes distinct aims to the trial by gathering preliminary data on the synergistic impact of dietary fiber and anthocyanins (via freeze-dried blueberry powder) on the gut-microbiota, gut-derived metabolites, and depressive symptoms in older adults. Participants will then be randomized to consume either 48 g of freeze-dried blueberry powder (\~600 mg of anthocyanins and \~8 g of fiber) or 48 g of a nutritionally matched placebo powder (devoid of anthocyanins and fiber) each day for a total of 12 weeks. At baseline, participants will be undergo assessments for depressive symptom severity and provide a fecal sample for gut microbiota and short chain fatty acid measurement. After 4, 8, and 12 weeks of consuming the powder there will be study visits that assess depressive symptom severity. Additionally, a final fecal sample will be taken after 12 weeks of the intervention.