The Effect of Probiotic Supplementation on Depressive Symptoms and Quality of Life in Patients After Myocardial Infarction: Results of a Preliminary Double-Blind Clinical Trial.

OBJECTIVE:Evidence indicates that probiotic supplements may improve or prevent depression. Little is known about the effects of probiotic supplementation on symptoms of depression and quality of life (QOL) in patients with myocardial infarction (MI). METHODS:This randomized, double-blind, and placebo-controlled clinical trial was performed in 44 patients with a recent diagnosis of MI who underwent percutaneous coronary intervention. Patients were randomly assigned to receive either capsules containing 1.6 × 10 colony-forming units of Lactobacillus rhamnosus capsules with their lunch (the active intervention group) or capsules that contained maltodextrin (the placebo control group) for 12 weeks. The Beck Depression Inventory, QOL, and biomarkers of oxidative stress (serum total antioxidant capacity), and malondialdehyde), and high-sensitivity C-reactive protein (hs-CRP) as inflammation marker were assessed. These measures were obtained at baseline and at 12 weeks' follow-up. RESULTS:The total Beck Depression Inventory score decreased significantly in patients who received probiotic supplements compared with the placebo group (-5.57 [6.1] versus -0.51 [2.8], p = .045). Improvements in the mean QOL score were also stronger in the probiotic versus the placebo group (23.6 [39.1] versus 0.44 [42.6], p = .023). In addition, increases in total antioxidant capacity (93.7 [88.4] versus 27.54 [64.7] mmol/l, p = .009) and decreases in malondialdehyde (-40.7 [63.73] versus -4.2 [67.6] nmol/ml, p = .033) and high-sensitivity C-reactive protein (-1.74 [0.70] versus 0.67 [1.27] mg/l, p = .040) levels were stronger in patients receiving probiotic supplementation than the placebo group. CONCLUSION:These data provide preliminary evidence that probiotic supplementation in patients with percutaneous coronary intervention post-MI has beneficial effects on depressive symptoms and markers of oxidative stress and inflammation. Multicenter studies with larger sample sizes are needed to replicate these findings and identify patient subgroups with the most benefit from probiotic supplementation. TRIAL REGISTRATION:www.irct.ir identifier: IRCT20121028011288N15.