Table 1.

Colorectal cancer–associated microbes

Organism	Natural reservoir	Evidence of association with CRC^a			Mechanisms identified in models^b	Effectors^b
Organism	Natural reservoir	Epidemiology	Microbial enrichment	Immune responses	Mechanisms identified in models^b	Effectors^b
Streptococcus gallolyticus	GI tract	+	−	+	Unknown	Unknown
Enterococcus faecalis	GI tract	−	−	−	ROS-mediated DNA damage	Unknown
Colibactin-producing Escherichia coli	GI tract	+	+	−	Toxin-mediated DNA damage	Colibactin (Pks)
Enterotoxigenic Bacteroides fragilis	GI tract	+	+	−	Inflammation and immune-cell infiltration	Bft toxin
Fusobacterium nucleatum	Oral cavity	+	+	−	Inflammation and immune-cell infiltration; disruption of antitumor immunity	FadA, Fap2

Abbreviations: CRC, colorectal cancer; GI, gastrointestinal; ROS, reactive oxygen species.

Evidence of association with CRC is based on microbial enrichment as described in the main text and epidemiological and human immune responses as described and classified in Reference 74.

As reported in References 2, 39, 48, 72, 92, 93, and 96.