Table 3.

The microbiome: cancer friend or foe.

Function	Microorganism	Type of Cancer	Mechanism	References
Cancer Therapy	Mycobacterium bovis BCG	Bladder	Stimulating the immune system and increasing the proinflammatory cytokines activation of cancer cells phagocytosis	[154,155,156,157,158]
	Streptococcus pyogenes OK-432	Lymphangioma Intraoral Ranula	Immune activation by increasing cytokine levels	[159,160,161,162]
	Clostridium novyi	Leiomyoma	Targeting and destroying tumor cells	[154,163,164,165]
	Salmonella Typhimurium VNP20009	Melanoma, Pancreatic	Helping antitumor drugs target cancer	[166,167]
	Magnetococcus marinus	-	Targeted transport vector	[168,169]
	Bifidobacterium Longum	Colorectal	Enhancing the body’s immune function and regulating the expression of tumor-related genes and cytokines	[170,171,172,173,174]
	Listeria Monocytogenes LADD strain	Cervical, Oropharyngeal, Pancreatic, Lung and Mesothelioma	Targeted transport vector	[175,176,177]
	Escherichia Coli	-	Targeted transport vector	[178,179]
Tumor Promoters	Gram-Negative Bacteria	Liver Colorectal	TLR2 and TLR4 mediated upregulation of Innate inflammation; Induction of IL-17/23 pathway cytokines	[180,181,182]
	Helicobacter Pylori	Gastric	Inducing inflammation	[149,183,184]
	Clostridium species	HCC	Production of deoxycholic acid from bile and inducing inflammation	[185]
	Enterotoxigenic Bacteroides Fragilis	Colon	Inducing inflammation	[186]
	Fusobacterium	Colorectal	Inducing inflammation and protecting tumors from an immune cell attack	[187,188,189]
	Escherichia Coli	Colorectal	PKS inducing DNA breaks	[190]
	Chlamydia Pneumoniae	Lung	C. pneumoniae protein interfering with host cell behavior	[191]
	Chlamydia Trachomatis	Cervical, Ovarian	Promotes host cell DNA double-strand breaks, induces host cell genome instability and even transformation	[192]