Results of cognitive measurements
| Test | Measure | CS* baseline to post-intervention | Random intercept model | Correlation with BDNF (including age) |
|---|---|---|---|---|
| Verbal Learning Memory Test | Immediate recall (Dg1–5) | t37.86 = −2.16, p = 0.037 | F2, 76.12 = 2.55, p = 0.084 | Probiotics: r = 0.26, p = 0.33 Placebo: r = −0.01, p = 0.97 |
| Intermediate recall (Dg5–Dg6) | t37.24 = 0.24, p = 0.82 | F2, 68.32 = 1.29, p = 0.28 | Probiotics: r = 0.04, p = 0.88 Placebo: r = −0.05, p = 0.86 | |
| Long-term recall (Dg5–Dg7) | t35.47 = −1.79, p = 0.082 | F2, 77.57 = 1.74, p = 0.18 | Probiotics: r = 0.10, p = 0.72 Placebo: r = 0.18, p = 0.52 | |
| Corsi block tapping test | Correct sequence forward | t35.15 = −0.55, p = 0.59 | F2, 79.51 = 0.09, p = 0.91 | – |
| Correct sequence backward | t37.08 = −1.43, p = 0.16 | F2, 79.92 = 1.44, p = 0.24 | – | |
| Trail Making Test | TMT A time | t29.95 = 0.081, p = 0.94 | F2, 71.57 = 0.06, p = 0.94 | – |
| TMT B time | t28.44 = −1.68, p = 0.10 | F2, 70.92 = 1.02, p = 0.36 | – | |
| 2-back task | Reaction time | t26.97 = 1.037, p = 0.31 | – | Probiotics: r = −0.29, p = 0.34 Placebo: = 0.50, p = 0.08 |
| Accuracy | t22.20 = 0.098, p = 0.92 | – | Probiotics: r = −0.44, p = 0.13 Placebo: r = 0.19, p = 0.53 |
BDNF = brain-derived neurotrophic factor; CS = Change Score; TMT = Trail Making Test.
↵* Calculated by subtracting the post-intervention score from the baseline score.