Table 2.

Various bacteria abundance in patients with CRC

Bacteria	Detection method	Sample (n)	Positive percentage	Sample type	Affiliation	Refs.
H. pylori	Multiplex serology	4063	41%	Serum	USA	[20]
H. pylori	ELISA	1712	46.1%	Serum	Germany	[21]
H. pylori	Multiplex serology	1488	90%	Serum	Spain	[22]
F. nucleatum	qPCR	160	66.9%	FFPE tissue	Korea	[23]
F. nucleatum	qPCR	100	75%	Frozen tissue	Japan	[24]
F. nucleatum	qPCR	39	82.1%	Tissue	Korea	[25]
E. coli	PCR	31	90%	Tissue	Germany	[26]
E. coli	PCR	48	16.7%	Tissue	Malaysia	[27]
E. coli	PCR	48	83%	Tissue	Iran	[28]
B. fragilis	PCR	49	88.5%	Mucosal tissue	USA	[29]
B. fragilis	PCpR	60	58.3%	Stool	Iran	[30]
P. anaerobius	qPCR	154	NA	Mucosa/Stool	China	[31]
P. gingivalis	qPCR	31	32.2%	Tissue	China	[32]
P. gingivalis	PCR	71	76%	Saliva	Turkey	[33]
E. faecalis	PCR	20	NA	Stool	India	[34]
E. faecalis	qPCR	9	22.2%	Stool	Italy	[35]
S. gallolyticus	qPCR	148	74%	Tissue	USA	[36]
S. gallolyticus	qPCR	190	3.2%	Tissue	Spain	[37]

ELISA enzyme-linked immunosorbent assay, qPCR quantitative real‐time polymerase chain reaction, FFPE formalin‐fixed paraffin‐embedded