Probiotics and the microbiome: Clinical intervention for anxiety and depression
LE3 .A278 2013
Bachelor of Science
The effects of probiotics on anxiety, depression, anxiety sensitivity, and associated physiological factors were examined. Forty-six participants consumed probiotics or placebo for 10 weeks each. The Depression, Anxiety, and Stress Scale (DASS) and the Anxiety Sensitivity Index (ASI) were completed by participants at the beginning and end of each phase, and additional health questions were answered biweekly. At the time of writing, all 46 participants had completed Phase 1 but only 11 had completed Phase 2. Contrary to the hypotheses, DASS and ASI scores decreased in both the probiotic and placebo groups, with DASS scores decreasing more with placebo than probiotic. Participant expectancies, higher initial DASS and ASI scores, catastrophizing, and allegiance bias may have contributed to the large placebo effect. Interestingly, the probiotic group lost an average of five pounds, whereas the placebo group maintained their body weight.
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