Notes:
- Host-genetic-driven increases in Enterobacteriaceae family and Enterobacteriales order were potentially related to a higher risk of SCZ, while Gammaproteobacteria class was related to a lower risk of SCZ
- Gut production of serotonin was potentially associated with a higher risk of SCZ.
- There is a strong relationship of lower platelet serotonin concentrations with depressive symptoms of SCZ.
- According to the principle of brain plasticity, glutamate signals are destroyed by serotonergic overdrive, leading to neuronal hypometabolism, synaptic atrophy, and gray matter loss in the end.
- Enterobacteriaceae family and Enterobacteriales order can produce SCFAs (e.g., acetic acid and formic acid) in carbohydrate fermentation, thus inducing serotonin biosynthesis by enterochromaffin cells which are the major producers of serotonin, and ultimately increasing the risk of SCZ.
- Porphyromonadaceae were associated with poor cognitive performance.
- Gut inflammation can induce activation of microglia and the kynurenine pathway, which activate systemic inflammation-inducing depressive or schizophrenic symptoms (1)