Table 2.

Preclinical studies exploring gut microbial alteration and its role in genetic-associated behavioral changes.

Genetic variant	Behavioral phenotype	Microbial changes	Functional validation method	Role of microbial remodeling	Refs
Chd8+/−	ASD-like anxiety, impaired social interaction, learning and memory deficits	Bacteroides uniformis ↓	Co-housing, mono-colonization	Increased excitory/Inhibitory (E/I) ratio	34
Shank3B−/−	ASD-like social deficits	Lactobacillus reuteri ↓	Mono-colonization	Increased level of oxytocin	35
Shank3−/−	ASD-like social deficits, repetitive behaviors	Lactobacillus reuteri ↓	Mono-colonization	GABA receptor subunits, oxytocin signaling	36
Cntnap2−/−	ASD-like social deficits	Lactobacillus reuteri ↓	Co-housing, fecal microbiota transplantation，mono-colonization	Increased tetrahydrobiopterin (BH4) metabolism pathway	21
EphB6−/−	Stereotyped behavior and social deficits, accompanied by anxiety-like behavior	Mucispirillum ↓	Fecal microbiota transplantation	Vitamin B6 homeostasis, decrease in dopamine	37
Nlrp3−/−	Depression and anxiety-like behavior	uncharacterized	Fecal microbiota transplantation	Astrocyte dysfunction, expression of circHIPK2	38
Ephx2−/−	Depressive-resilient phenotypes	Faecalibaculum rodentium ↓	Fecal microbiota transplantation, mono-colonization	Systemic inflammation, and synaptic proteins in the prefrontal cortex	39
Chrna7−/−	Depression-like behavior	uncharacterized	Fecal microbiota transplantation	synaptic proteins in the prefrontal cortex	40