Table 2.

Summary of studies showing role of bacterial metabolites on nervous health and behavior

Bacterial metabolite	Class	Study Model	Host response	Reference
CDCA and DCA	Bile Acid	BA injection in Sprague Dawley rats	Increased BBB permeability	(Quinn et al. 2014)
Obeticholic acid (OCA)	Bile Acid	Oral gavage of BA in HFHS (high fat, high sugar) fed mice	Improve metabolic disorder driven Anxiety	(Wu et al. 2021)
Sodium propionate, sodium butyrate and sodium acetate	SCFA	Added to drinking water in mice	Increased microglial maturation and function	(Erny et al. 2015)
Sodium butyrate	SCFA	BTBR autism mouse model	Attenuates social behavior deficits	(Kratsman et al. 2016)
Sodium butyrate	SCFA	Chronic mild stress model in Wistar rats	Anti-depressant and anti-manic properties	(Resende et al. 2013)
Propionate	SCFA	Experimental autoimmune encephalomyelitis	Ameliorate experimental autoimmune encephalomyelitis (EAE) disease course	(Haghikia et al. 2015)
P-cresol	Aromatic acid metabolite	BTBR autism mouse model	Triggers anxiety and hyperactivity at lower doses and exacerbate autism like behavior at higher dose	(Pascucci et al. 2020)
TMAO	Amine oxide	C57Bl/6 mice on low-choline diet supplemented with TMAO	Induced neuroinflammation and decline in cognitive function	(Brunt et al. 2021)
Tryptophan	Amino acid	EAE mouse model of multiple sclerosis	Decreased neuroinflammation and decreased EAE score	(Rothhammer et al. 2016)