Abstract

This randomized controlled trial enrolled 312 patients with major depressive disorder initiating SSRI therapy. Metagenomics analysis at baseline, 8 weeks, and 24 weeks reveals that Lactobacillus rhamnosus abundance at baseline predicts treatment response (AUC 0.74). Dietary microbiome modulation augments antidepressant efficacy by 24% versus placebo in non-responders.