A small randomized, double-blind pilot trial in India found that seniors receiving standard antidepressant care reported slightly greater improvements in depression and anxiety symptoms when a daily probiotic was added for 12 weeks, compared with a placebo.
The pilot study enrolled 58 adults in India who were at least 60 years old and had moderate depression. Participants continued standard antidepressant treatment and were randomly assigned 1:1 to receive either a daily probiotic supplement or an identical placebo for 12 weeks, followed by an additional 12 weeks of monitoring.
Both groups improved substantially over the course of the study. However, those given probiotics showed somewhat larger reductions in depression and anxiety symptoms based on validated psychological rating scales. Researchers also assessed serum brain-derived neurotrophic factor (BDNF) and profiled gut microbes using fecal microbiota analysis.
The study did not find clear additional improvements in overall quality of life for the probiotic group compared with placebo.
The findings were published in the Journal of the American Geriatrics Society.
"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 of the Indian Council of Medical Research — National Institute for Research in Bacterial Infections, Kolkata.
