Overview
- A peer‑reviewed pilot randomized, double‑blind, placebo‑controlled trial published June 17, 2026, reported modest additional reductions in depressive and anxiety scores for seniors who took a daily probiotic alongside standard antidepressants.
- The PRODG trial enrolled 58 adults aged 60 and older in India who continued their usual antidepressant care and were randomized 1:1 to receive probiotics or placebo for 12 weeks with a further 12 weeks of follow‑up.
- Both the probiotic and placebo groups showed large overall clinical improvement during the study, but mixed‑effects analyses found lower average depression and anxiety scores in the probiotic arm while quality‑of‑life measures did not show extra benefit.
- Investigators measured serum BDNF, a blood protein tied to nerve growth and brain plasticity, and profiled stool microbes; the probiotic group had higher BDNF and more of the supplemented strains but causal mechanisms remain unproven and study drop‑out was high.
- Study authors characterize the results as encouraging yet preliminary and are planning a larger, multi‑center trial to test how big and lasting the benefit is and whether probiotics could be a safe, low‑cost adjunct for geriatric depression.