Probiotics reduce depression, suggest clinical studies

Posted on Thu, 15 Sep 16

There is increasing interest in the use of probiotics for mental health. For the first time a review of relevant clinical studies has suggested probiotics help to reduce symptoms of depression. 

A vast number of bacteria in your digestive system make up what is referred to as the microbiome, which is known to influence brain health via a bi-directional communication network called the gut-brain-axis. 

Better microbial balance in your gut may help “keep the peace” in your brain, which is why therapeutics that can influence this balance and subsequent mental health, such as probiotics, are of interest scientifically [1].

Recently there have been studies looking specifically at the anti-stress and mood stabilizing effects of probiotics, but until now they have not been rigorously reviewed in their entirety. A systematic review and meta-analysis identified 5 relevant clinical studies and collated the data to identify if there was any benefit [2]. 

Overall the analysis found that probiotics significantly decreased symptoms of depression in non-clinically depressed subjects (4 studies) and patients with major depressive disorder (1 study). 

“The ongoing exploration of the human microbiome promises to clarify the link between the gut and the brain,” said the study investigators. “Scientists are increasingly recognizing that the gut microbiome might influence neuropsychiatric symptoms and might be a tractable target for novel treatment options.”

“The findings suggest an important role for probiotics in reducing the risk of depression in non-depressed individuals.”

References: 

1. Mu C, Yang Y, Zhu W. Gut Microbiota: The Brain Peacekeeper. Front Microbiol. 2016 Mar 17;7:345.
2. Huang R, Wang K, Hu J. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients. 2016 Aug 6;8(8).