Written by Chrystal Moulton, Staff Writer. Patients assigned to probiotic treatment had significant decrease in depression score at the end of treatment [p< 0.05] and at follow-up (8-weeks later) [p< 0.01].
Although research indicates gut microbiota may affect depressive behavior and brain function1, few studies examine the effect of probiotics on symptoms of major depressive disorder2-4. In a randomized placebo-controlled trial5, researchers examined the effect of probiotic supplementation plus conventional treatment on symptoms of major depressive disorder. They also explored the effects of probiotic supplementation on gut microbiota, brain structure, and neural activity.
Sixty eligible patients were recruited from an inpatient psychiatric clinic. Patients were 18years and older, already taking medication for their depression, and had scores >7 on the Hamilton Rating Scale for Depression (HAM-D). Each patient was randomly assigned to the intervention (probiotic supplementation) or placebo for 4 weeks. Brain imaging, stool sampling, and clinical measures were done at baseline and at the end of 4weeks. A follow-up assessment was then conducted 4 weeks after completion of the intervention (week 8) at which point only stool sample and clinical measurements were conducted. Patients in the intervention group were given Vivomixx®, a probiotic supplement containing 8 different strains of mainly Bifidobateria and Lactobacilli. The primary clinical measure was the Hamilton Rating Scale for Depression (HAM-D). Other clinical measures include Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory-1, and the Gastrointestinal Symptom Rating Scale (GSRS). Gut microbiota was assessed through stool sampling. Computational Anatomy toolbox scans and functional MRI were done to reveal structural and neural activation changes in the brain. These images were compared to healthy controls (individuals without depression) for statistical analysis.
After 4 weeks, 47 patients completed the trial (probiotics group= 21, placebo= 26). No clinical differences were observed at baseline. Researchers observed a decrease in HAM-D scores over time in both groups. A significant main effect of time was observed in both the intent-to-treat (assessing data from all patients) and modified intent-to-treat model (assessing data from compliant patients) [p< 0.001]. However, a significant time by group effect was observed only in the modified intent-to-treat model (assessing data from compliant patients) [p< 0.05]. A significantly greater decrease in HAM-D scores was found in the probiotics group from baseline to week 4 (p< 0.05) and baseline to follow-up (p< 0.01). No significant difference was observed in microbial diversity following probiotic therapy. Patients in the probiotic group had a significant increase in the Lactobacilli strain while patients in the placebo group had an increase in the Rumminococcus strain. Additional analysis showed that Lactobacillus was negatively associated with HAM-D scores (p< 0.05) and positively associated with GSRS scores (p< 0.01). Rumminococcus ASV was also associated with decrease in HAM-D scores in the placebo group (p< 0.05). Furthermore, gray matter volume significantly increased in the probiotic group compared to placebo (area: calcarine sulcus extending in the lingual gyrus; p< 0.027). There was also a significant decrease in activation of the right and left putamen among participants in the probiotics group (p< 0.001). However, this was not significant when compared to the placebo. No significant relationships were observed for clinical measures and functional or structural brain changes.
In this study, probiotic supplementation improved depressive symptoms in patients with major depressive disorder. The researchers noted this effect was observed in patients who were compliant to the treatment. They saw a 55% remission in the probiotics versus 40% remission in the placebo group at follow-up (week 8). A larger study will be needed to verify these results.
Source: Schaub, Anna-Chiara, Else Schneider, Jorge F. Vazquez-Castellanos, Nina Schweinfurth, Cedric Kettelhack, Jessica PK Doll, Gulnara Yamanbaeva et al. “Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial.” Translational Psychiatry 12, no. 1 (2022): 1-10.
© The Author(s) 2022
Click here to read the full text study.
Posted August 17, 2022.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
- Cryan JF, Dinan TG. Mind-altering microorganisms: the impact of the gut microbiota on brain and behaviour. Nature reviews neuroscience. 2012;13(10):701.
- Majeed M, Nagabhushanam K, Arumugam S, Majeed S, Ali F. Bacillus coagulans MTCC 5856 for the management of major depression with irritable bowel syndrome: a randomised, double-blind, placebo controlled, multi-centre, pilot clinical study. Food Nutr Res. 2018;62doi:10.29219/fnr.v62.1218
- Kazemi A, Noorbala AA, Azam K, Eskandari MH, Djafarian K. Effect of probiotic and prebiotic vs placebo on psychological outcomes in patients with major depressive disorder: A randomized clinical trial. Clinical nutrition (Edinburgh, Scotland). Apr 2019;38(2):522-528. doi:10.1016/j.clnu.2018.04.010
- Akkasheh G, Kashani-Poor Z, Tajabadi-Ebrahimi M, et al. Clinical and metabolic response to probiotic administration in patients with major depressive disorder: A randomized, double-blind, placebo-controlled trial. Nutrition. 2016;32(3):315-320.
- Schaub AC, Schneider E, Vazquez-Castellanos JF, et al. Clinical, gut microbial and neural effects of a probiotic add-on therapy in depressed patients: a randomized controlled trial. Transl Psychiatry. Jun 3 2022;12(1):227. doi:10.1038/s41398-022-01977-z
