Table 2.

Comparison of gut microbiota between patients with colorectal cancer and healthy individuals.

	Country (Author & Year)	Sample size	Sample type	Sequencing method	Changes of gut microbiota after cholecystectomy
1	China (Wang et al., 2012) (19)	102	Stool	16S rRNA	The diversity of microbiome is basically stable. Phylum Firmicutes, Proteobacteria, Actinomycetes↑ Bacteroides, Fusobacteria↓ Genus Porphyromonas, Escherichia, Shigella, Enterococcus, Streptococcus, Peptostreptococcus↑ Bacteroides, Rossella, Alternaria, Eubacteria, Trichospirillum↓
2	China (Wu et al., 2013) (50)	39	Stool	16S rRNA	The diversity of microbiome is basically stable. Phylum Fusobacterium↑ Family Eubacteriaceae, Clostridiaceae, Staphylococcus, Enterococcus, Fusobacteria, Campylobacter, Porphyridaceae↑ Genus Bacteroides, Alternaria, Blautella, Dallella, Fusobacterium, Campylobacter, Escherichia, Shigella, Odorbacterium, Oscillatoria, Testa Lactobacillus, Rumenococcus↑ Rossella, Faecalibacterium↓
3	America (Ahn et al., 2013) (49)	151	Stool	16S rRNA	The diversity of microbiome declined. Phylum Bacteroides↑ Firmicutes↓ Genus Porphyromonas, Fusobacterium, Mirabilis↑ Faecococcus, Trichospirillum↓
4	America (Zackular et al., 2014) (51)	60	Stool	16S rRNA	Family Porphyridaceae, Enterobacteriaceae↑ Lacetospiraceae↓ Genus Porphyromonas, Fusobacterium↑ Bacteroides↓
5	France (Zeller et al., 2014) (52)	114	Stool	Metagenomic sequencing	The diversity of microbiome is basically stable. Phylum Bacteroides, Fusobacteria, Proteobacteria↑ Actinomycetes, Firmicutes↓ Species Saccharolytic Porphyromonas, Oral Peptostreptococcus, Fusobacterium nucleatum↑
6	Australia (Feng et al., 2015) (53)	109	Stool	Metagenomic sequencing	The diversity of microbiome declined. Genus Bacteroides, Alternaria, Bileophilus, Trichospira, Escherichia, Micromonas, Fusobacterium↑ Bifidobacterium, Streptococcus, Rumenococcus↓
7	China (Nakatsu et al., 2015) (46)	113	Tissue	16S rRNA	Genus Fusobacterium, Gemini, Peptostreptococcus, Micromonas, Streptococcus granulosus↑ Species Bacteroides fragilis↑
8	America (Baxter et al., 2016) (54)	292	Stool	16S rRNA	Genus Porphyria, Peptostreptococcus, Fusobacterium, Micromonas, Prevotella, Gemini↑ Species Saccharolytic Porphyromonas, Fusobacterium nucleatum, Micromonas parvum, Oral Peptostreptococcus↑
9	Ireland (Flemer et al., 2017) (55)	115	Stool/ Tissue	16S rRNA	Genus Bacteroides, Rossella, Rumenococcus, Oscillatoria, Porphyromonas, Peptostreptococcus, Micromonas, Fusobacterium↑
10	China (Yu et al., 2017) (47)	128	Stool	Metagenomic sequencing	The diversity of microbiome declined. Phylum Fusobacteria, Basidiomycota↑ Species Micromonas parvum, Oral Peptostreptococcus, Fusobacterium nucleatum, Bacteroides fragilis, Solobacterium moorei↑
11	Saudi Arabia (Alomair et al., 2018) (56)	58	Tissue	Metagenomic sequencing	The diversity of microbiome is basically stable. Genus Peptostreptococcus, Porphyromonas, Listeria, Atopobium, Burkholderia, Collins, Comamonas, Fusobacterium↑
12	Japan (Yachida et al., 2019) (58)	616	Stool	Metagenomic sequencing	The diversity of microbiome increased. Phylum Firmicutes, Fusobacteria, Bacteroides↑ Genus Bacteroides, Peptostreptococcus↑ Prevotella, Bifidobacterium↓ Species Fusobacterium nucleatum, Micromonas parvum, Streptococcus oralis, Solobacterium moorei↑ Phascolarctobacterium succinatutens, Desulfovibrio longreachensis, Atopobium parvulum↓
13	Italy (Thomas et al., 2019) (57)	826	Stool	Metagenomic sequencing	The diversity of microbiome increased. Genus Peptostreptococcus, Clostridium, Porphyromonas, Escherichia coli↑ Bifidobacterium, Trichospirillum, Alternative Mycobacterium↓ Species Fusobacterium nucleatum, Porphyromonas saccharolyticus, Micromonas parvum, Oral Peptostreptococcus, Escherichia coli↑