It has been shown that dysbiosis might have a role in developing of chronic inflammation and depression. In this study, we are interested in exploring of anti-inflammatory and anti-depressant effects of Lactobacillus Rhamnosus G (LGG), a probiotic strain, alone or in combination with a prebiotic, Inulin, in patients with coronary artery disease (CAD).

This randomized, double-blind clinical trial was held on 96 patients with CAD. Patients were randomly allocated into four different groups: LGG [a capsule/day, contained 1.9 × 10⁹ colony-forming unit of Lactobacillus Rhamnosus G], inulin (15 g/day), co-supplemented (LGG and inulin), and placebo. Participants consumed the supplements for two months. Beck Depression Inventory (BDI), MacNew questionnaire and Spielberger state-trait anxiety inventory (STAI-Y) were used to assess depression, quality of life and anxiety, respectively. Serum levels of C-reactive protein (hs-CRP), lipopolysaccharide (LPS), tumor necrosis factor (TNF)-α, and Interleukin (IL)-10 were also measured.

Probiotic-Inulin Co-supplementation significantly decreased BDI (−11.52 ± 0+3.20 vs. +2.97 ± 0.39, P = 0.001), STAI-state (−17.63 ± 3.22 vs. −0.60 ± 0.33, P = 0.021), and STAI-trait (−24.31 ± 7.41 vs. −1.45 ± 0.66, P = 0.020) scores, hs-CRP (−1.69 ± 0+66 vs. +0.82 ± 0.39 mg/dL, P = 0.020), LPS (−22.02 ± 5.40 vs. +0.31 ± 0.18 (EU/L), P = 0.047), and TNF-α (−25.05 ± 7.41 vs. +0.79 ± 0.71 (ng/L), P = 0.032) in comparison to placebo.

Co-supplementation of probiotics and inulin in CAD subjects for eight weeks had beneficial effects on depression, anxiety, and inflammatory biomarkers. Adding inulin to probiotic supplements improved psychological outcomes and inflammatory biomarkers more effectively than two supplements separately.

Trial registration: Iranian Registry of Clinical Trials identifier: IRCT20180712040438N4..