Probiotics could help treat depression

by Wiley

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In a pilot clinical trial published in the Journal of the American Geriatrics Society that included older adults with depression receiving standard care, adding probiotic therapy produced modest but meaningful reductions in depressive and anxiety symptoms compared with adding a placebo. However, both groups demonstrated substantial overall improvements during follow-up.

For the trial, 58 participants in India aged 60 and older with moderate depression were randomly assigned 1:1 to receive daily probiotics or a placebo for 12 weeks, alongside standard antidepressant care. They were followed for another 12 weeks.

Based on validated psychological scores, a biomarker (serum brain-derived neurotrophic factor level) and fecal microbiota profiling, investigators found that probiotics helped improve patients' symptoms but did not confer clear additional gains in quality of life compared with placebo. The findings support probiotics as a safe, biologically plausible adjunct to standard care, but larger trials are needed.

"The results of our study are novel, and we are now planning a follow-up, larger-scale clinical trial due to the encouraging findings," said co-corresponding author Dr. Saibal Das, MBBS, MD, DM, Ph.D., of the Indian Council of Medical Research-National Institute for Research in Bacterial Infections, Kolkata.

"My vision is to develop affordable health care solutions and make them available to the larger population for meaningful public health impact," added co-corresponding author Abhinaba Ghosh, MBBS, MSc, Ph.D., a physician-neuroscientist from Tata Medical Center, Kolkata.

Publication details

Efficacy of Adjunct PRObiotics in Moderate Unipolar Depression in Geriatric Patients: A Randomized Double-Blind Multicentric Trial (PRODG), Journal of the American Geriatrics Society (2026). DOI: 10.1111/jgs.70530

Journal information: Journal of the American Geriatrics Society

Key medical concepts

Major Depressive DisorderBrain-Derived Neurotrophic Factor

Clinical categories

PsychiatryPsychology & Mental healthHealthy aging Provided by Wiley Who's behind this story?

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