Table 1.

Dysbiosis of gut microbiota in ALS.

	Experimental subject		Conclusion	Ref.
	Animal model	Human volunteer
Ning et al	_	20,806 cases with ALS and 59,804 controls (GWAS summary statistics from IALSC); 18,340 participants (GWAS summary statistics from the MiBioGen); 7824 participants (GWAS summary statistics from TwinsUK and KORA)	Decreased abundance of Fusicatenibacter and Catenibacterium; increased abundance of Lachnospira; these changes may be related to the higher risk of ALS	[44]
Zhang et al	_	20,806 cases with ALS and 59,804 controls (GWAS summary statistics from IALSC); 1812 sanples (GWAS summary statistics); 7824 adult individuals (GWAS summary statistics from 2 European cohorts)	Increased abundance of OTU4607 Soutella and Lactobacillales order; this change may be correlated with the genetically predicted increased susceptibility to ALS	[45]
Zeng et al	_	8 females and 12 females diagnosed with ALS; 8 females and 12 females matched controls	Up-regulation of Bacteroidetes, Kineothrix, Parabacteroides, Odoribacter, Sporobacter, and unclassified Porphyromonadaceae	[40]
Hertzberg et al	_	10 patients diagnosed with ALS (3 females and 7 males) and their opposite sex spouses (7 females and 3 males); 10 opposite sex couples' healthy controls	Compared with their spouses, down-regulation of Prevotella spp and P.timonensis; up-regulation of species richness and uniformity of gut microbiota.	[46]
Figueroa-Romero et al	SOD1(G93A) mice	_	Down-regulation of Akkermansia, Coriobacteriaceae and Adlercreutzia	[37]
Nicholson et al	_	26 females and 40 males diagnosed with ALS; 36 females and 25 males' healthy controls; 7 females and 5 males' Neurodegenerative controls	Decreased abundance of Roseburia intestinalis and Eubacterium rectale (two major butyrate-producing bacteria); decreased abundance of eight major butyrate-producing bacteria	[47]
Fang et al	_	6 patients diagnosed with ALS; 5 healthy controls	Decreased abundance of Anaerostipes, Lachnospiraceae (two butyrate-producing bacteria) and Oscillabacter; Increased abundance of Dorea	[41]
Zhai et al	_	4 females and 4 males diagnosed with ALS; 4 females and 4 males' healthy controls	Decreased abundance of Faecalibacterium (one butyrate-producing bacteria)	[43]
Zhang et al	SOD1(G93A) mice	_	Decreased abundance of Lachnospiraceae (one butyrate-producing bacteria) occurred at the early stage of ALS disease	[48]
Wu et al	SOD1(G93A) mice	_	Decreased abundance of Butyrivibrio Fibrisolvens (one butyrate-producing bacteria)	[49]