Gut Bacteria Could Help with Depression

Major depressive disorder (MDD) is one of the most prevalent and burdensome psychiatric disorders but current treatment options are still unsatisfying. Two-thirds of depressed patients do not respond adequately to initial antidepressant medication and up to 30% of treatment-resistant patients experience residual symptoms when receiving optimized treatments.

That is why more efficient treatment approaches are urgently needed. A recent meta-analysis demonstrated the potential of probiotic treatments for ameliorating mild and moderate depressive symptoms in patients suffering from several illnesses. 

Recently, a group of researchers studied the use of probiotics in the treatment of depression. Their study appears in the journal Translational Psychiatry. 

More Lactobacilli, Less Depressive Symptoms

For the study, the team performed a randomized controlled trial and divided patients into 2 groups, the first group received probiotics over four weeks while the other received a placebo. All patients had depression and were evaluated using the Hamilton Depression Rating Scale. 

The probiotic supplement was Vivomixx, a supplement containing eight different strains of bacteria, it included Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus delbrueckii. The daily dose contained 900 billion CFU/day. 

The team found that the participants who received the probiotics had a higher reduction in their depressive symptoms and also observed an increase in the bacteria called Lactobacillus in the gut flora of the participants in the treatment group. 

The researchers concluded that using the probiotic depressive symptoms ameliorated along with changes in the gut microbiota and brain, highlighting the role of the microbiota-gut-brain axis, and how important it is for multiple health conditions. 


Schaub, AC., Schneider, E., Vazquez-Castellanos, J.F. et al. Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial. Transl Psychiatry 12, 227 (2022). 

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