Can Probiotics Help Depression?

Here at Healthpath, we’re proud to offer evidence-based advice. However, we’re aware that science can seem a bit impenetrable and dry. Boring, even.

We also believe that education is the first step to regain control. We read a lot of scientific papers, so we thought it would be a good idea to create a digest (no pun intended) of some of the key research.

We hope these plain-English versions bring the science to life and—even more importantly—help you address your symptoms for good.


“Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials”


What’s the title in plain English?

A report looking at several studies to work out whether probiotics can improve depression


What did they do?

Researchers combined the data from five studies. They then analysed this data to create a ‘pooled estimate’ of the evidence, allowing them to assess the overall effect of probiotics in both depressed and non-depressed people.

Free gut health consultation with an expert


What are the take-home points from the study?

1. Compared to taking a placebo (a sugar pill), the results showed that probiotics significantly decreased depression scores in those who were diagnosed as having major depressive disorder. The effect of probiotics on non-depressed individuals was small but positive, indicating there could be a preventive role for probiotics in healthy people.

2. The researchers then looked at how age was impacted, finding that probiotics were more effective at reducing depressive symptoms in those aged under 60 compared to older people.

3. This type of study (meta-analysis) draws similar scientific studies together in order to present a weighted estimate of results. However, this comes with a certain degree of error. The researchers attempted to limit this by considering the comparability between the studies by selecting ‘high-quality’ trials that were all deemed to have a low risk of bias. However, there were several limitations between individual studies, including differences in probiotic strains, dose and the length of treatment.


The Healthpath view

Several studies have suggested that our gut bacteria can affect our mood. Probiotics could be a suitable option but, based on the limitations of meta-analysis, it’s difficult to draw any strong conclusions from this study. Additional research in well-controlled studies is needed.

Read the full published study here.

Tegan Philp BA PgDip MSc is a Registered Nutritional Therapist. Passionate about all things gut-related, her master’s dissertation was on the role of the microbiome in cardiovascular outcomes. Tegan has over eight years’ experience working for leading nutrition colleges in both Australia and the UK. You can learn more about Tegan on her practitioner page or connect with her via LinkedIn.


Ref: Huang, R., Wang, K., & Hu, J. 2016. Effect of Probiotics on Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients, 8(8), 483.

Other articles you might like