Table 2.
Summary of probiotic studies on anxiety and/or depressive symptoms in humans. ↑ increase, ↓ decrease.
| Paradigm | Probiotic (Dose) | Duration of Treatment | Effects | Reference |
|---|---|---|---|---|
| Adult males and females (healthy) | L. helveticus R0052 and B. longum R0175 (3 × 109 CFU, daily) | 30 days | ↓ anxiety and depression HAD scores No effect on BDI or BAI scores |
[111] |
| Adult males (healthy) |
L. rhamnosus JB-1 (1 × 109 CFU, daily) |
4 weeks | No differences between probiotic and placebo for BDI, BDAI, or serum cytokine levels | [112] |
| Adult males and females (mild to moderate depression: PHQ9 score 5–19) | Bacillus subtilis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus delbrueckii ssp. Bulgaricus, Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactobacillus helveticus, Lactobacillus salivarius, Lactococcus lactis ssp. Lactis, Streptococcus thermophilus. (2 × 109 CFU, daily) | 4 weeks | No effect of probiotic on salivary cortisol or serum CRP Probiotic ↓ PHQ9 scores |
[113] |
| Adult males and females (moderate or severe depression: ≥11 QIDS-SR16 or ≥14 DASS-42) | L. helveticus R0052 and B. longum R0175 (3 × 109 CFU, daily) | 8 weeks | No effects of probiotic treatment on self-reported depression or anxiety scales, and no effect on serum CRP, IL-1B, IL-6, TNF, BDNF, or vitamin D | [114] |
| Adult males and females (MDD diagnosis, moderate-severe symptoms) | L. acidophilus, L. casei, and B. bifidum (6 × 109 CFU, daily) | 8 weeks | Probiotic ↓ BDI score compared to placebo Probiotic ↓ serum CRP level compared to placebo |
[115] |
| Adult males and females (MDD diagnosis, mild-moderate symptoms) | L. helveticus R0052 and B. longum R0175 (1 × 1010 CFU, daily) | 8 weeks | Probiotic ↓ BDI score compared to placebo Probiotic ↓ serum kynurenine/tryptophan ratio compared to placebo |
[109] |
| Adult pregnant women (at least mild anxiety or depression: ≥10 EPDS or ≥40 STAI) | B. bifidum W23, B. lactis W52, L. acidophilus W37, L. brevis W63, L. casei W56, L. salivarius W24, Lc. Lactis W19, Lc. Lactis W58 (5 × 109 CFU, daily) | From 26 to 30 weeks gestation until delivery | No effect of probiotic on perinatal maternal depression (EPDS) or anxiety (STAI) scores | [116] |
| Adult pregnant women (healthy) | L. rhamnosus HN001 (6 × 109 CFU, daily) | From 14 to 16 weeks gestation until 6 months postpartum | Probiotic significantly ↓ depression (EPDS) and anxiety (STAI) scores compared to placebo | [117] |
| Adult pregnant women (obese: BMI ≥ 30 kg/m2) | L. rhamnosus GG and B. lactis BB12 (6.5 × 109 CFU, daily) | From 12 to 18 weeks gestation until 36 weeks gestation | No effect of probiotic on depression (EPDS) or anxiety (STAI-6) scores compared to placebo | [118] |