Probiotics Improve Major Depressive Disorder 

Probiotics could also be called “Psycho-biotics” because of the significant influence that they have on brain and mood.

Many studies have looked at the connection between the gut microbiome and mood. Chen et al.,2018 analyzed differences in the composition of the gut microbiota in both men and women with major depressive disorder (MDD) and compared them to healthy controls without MDD.

Fecal samples were taken from all subjects and were then analyzed. Various tests showed significant differences in microbial composition between both men and women with MDD and the healthy group.

This supports the notion that an altered microbiome plays a role in psychological disorders such as major depressive disorder.

Kazemi et al., 2018 conducted an 8 week study to see the effect that probiotics (strains Lactobacillus helveticus and Bifidobacterium longum) , prebiotics and placebo had on 110 people with MDD.

Scientists measured the kynurenine/tryptophan ratio and tryptophan/branch chain amino acids ratio as secondary outcomes. They also had patients use the Beck Depression Inventory Score to keep an account of the severity of their symptoms/mood.

Once again, supplementing for 8 weeks with probiotics had a significant improvement in BDI score & secondary outcomes when compared to placebo group. No significant improvement was noted in the prebiotic group.

Conclusion: Probiotic supplementation can help improve major depressive disorder. 

I recommend Therbiotic Complete by Klaire Labs.

Other Things To Do: 

Avoid foods that contain wheat/gluten and Dairy which can inflame the brain and worsen any neurological conditions, mood disorders and gut issues.

Have your doctor test your Homocysteine levels. If your homocysteine is >7.0 your body is requiring more folate (not folic acid) and this can be a cause of depression. I recommend Methyl Protect by Xymogen.

White bottle of B vitamins










Chen, J., Zheng, P., Liu, Y., Zhong, X., Wang, H., Guo, Y., & Xie, P. (2018). Sex differences in gut microbiota in patients with major depressive disorder. Neuropsychiatric Disease and Treatment, 14, 647-655.

Kazemi, A., Noorbala, A. A., Azam, K., Eskandari, M. H., & Djafarian, K. (2018). Effect of probiotic and prebiotic vs placebo on psychological outcomes in patients with major depressive disorder: A randomized clinical trial. Clinical Nutrition.

Author: Melissa Mullin