Table 3 Probiotic effects on resting state functional connectivity
Study | Data analyses approach | Study design | Direction of effect | Localisation of effect |
|---|---|---|---|---|
Bagga et al.38 | ICA, GLM, whole-brain | Parallel groups, baseline and 4 weeks | Probiotic < placebo | default mode network (frontal pole, superior frontal gyrus and paracingulate gyrus) and in pre- and postcentral gyri. |
Rode et al.43 | SBC with several networks as seeds (default mode, salience, frontoparietal, language, cerebellar, dorsal attention, sensorimotor, visual) | Cross-over, 4 weeks, (no baseline) | Probiotic < placebo | Left supramarginal gyrus to left postcentral gyrus; |
Probiotic < placebo | Right supramarginal gyrus to precuneus cortex, bilateral intracalcarine cortex, bilateral supracalcarine cortex; Right cerebellum | |||
Probiotic < placebo | Left posterior parietal cortex to the left middle frontal gyrus, left precentral gyrus | |||
Probiotic > placebo | Medial prefrontal cortex to right postcentral gyrus, right superior parietal lobule | |||
Probiotic > placebo | Right inferior frontal gyrus to middle temporal gyrus (temporooccipital part right), inferior temporal gyrus (temporooccipital part right), lateral occipital cortex (inferior division right) | |||
Ascone et al.40 | SBC, flexible factorial design, seeds: bilateral, right, left hippocampus | Parallel groups, baseline, 4 weeks | No significant main effects, no time*group interactions | - |
Yamanbaeva et al.54 | SBC, 2×2 mixed ANOVA, combined seed of: subcallosal cortex/subgenual anterior cingulate cortex, hippocampus, amygdala, temporal pole, insula, orbitofrontal cortex. The resulting two clusters in the precuneus and the left superior parietal lobule/supramarginal gyrus were used for post hoc tests. | Parallel groups, baseline, 31 days significant time*group interactions | Probiotic < placebo | left superior parietal lobule/supramarginal gyrus to subcallosal cortex, right amygdala, left hippocampus |
Probiotic > placebo | left superior parietal lobule/supramarginal gyrus to left orbitofrontal cortex | |||
Probiotic > placebo | precuneus to subcallosal cortex*, right* & left amygdala, bilateral hippocampus, left temporal pole (*not significant after correction for baseline differences) | |||
Tillisch et al.31 ** | MVA, seeds periaqueductal grey, somatosensory cortex, insula) derived from emotional task-based activity | Parallel groups, baseline, 4 weeks | Correlations with task-induced regional brain activity and connectivity | Periaqueductal grey (part of midbrain region) to thalamus, insula, cingulate gyrus, amygdala, hippocampus, parahippocampal gyrus, basal ganglia, region BA40 |
