Table 4.

The impact of titanium dioxide nanoparticles on gut microbiota.

Reference	[17]	[58]	[151]	[78]	[79]	[52]	[53]	[54]	[59]	[152]	[56]	[57]	[155]	[55]	[159]	[77]	Total
																	↑	↓
α-diversity
Richness	-	N	-	↓	-	-	-	↓	-	↓	N	N	↓	-	N	-	0	4
Diversity	-	N	-	N	-	-	-	↓	-	↓	N	N	-	-	N	-	0	2
β-diversity	S	-	-	N	-	-	-	S	S	S	N	N	S	-	N	-	S = 5
Phylum
Bacteroidetes		↑				↓	↓	↓					↑			↑	3	3
Verrucomicrobia								↓					↑				1	1
Firmicutes						↑	↑	↑					↑	↑		↑	6	0
Proteobacteria															↑	↓	1	1
Actinomycetes		↑								↑							2	0
Cyanobacteria										↑							1
Deferribacteres										↑							1
Genus
Bifidobacterium		↓				↓											0	2
Bacteroides								↓							↑		1	1
Parabacteroides												↑					1	0
Lactobacillu		↓	↑			↓						↑					2	2
Prevotella															↓		0	1
Turicibacter											↑						1	0
Akkermansia								↓									0	1
Adlercreutzia												↓					0	1
Barnesiella								↓									0	1
Rhodococcus															↑		1	0
Lawsonia													↑				1	0
Allobaculum												↑					1	0
Enterobacteria			↑														1	0
Acetobacteria			↑														1	0
Species
Clostridium leptum	↓																0	1
Clostridium cocleatum					↑												1	0
Bacteroides ovatus					↓												0	1

Abbreviations: “↑”—higher α-diversity or bacteria are more abundant; “↓”—Lower α-diversity or bacteria are less abundant; S—significant difference found in β-diversity.