Table 1.

Identification of significant differences in bacterial distribution between the nickel oxide nanoparticles (NiO NPs)-exposed (low- and high-dose groups) and control groups based on linear discriminant analysis effect size (LEfSe) analysis.

Day	Phylum	Class	Order	Family	Genus	Species
1 day	Proteobacteria	Alphaproteobacteria	Rhizobiales	Methylobacteriaceae	Methylorubrum	Methylorubrum_populi
		Betaproteobacteria †	Burkholderiales †
	Firmicutes	Bacilli	Lactobacillales	Enterococcaceae
4 weeks	Proteobacteria	Betaproteobacteria	Burkholderiales	Sutterellaceae	Sutterella

Order burkholderiales were enriched in the NiO NPs-exposed group compared with the control group at 1 day after instillation. The levels of terms in bold were statistically different between the NiO NPs-exposed and control groups by LEfSe. ^† Higher in the NiO NPs-exposed group than it was in the control group.