Table 1.

Intratumoural microbiota in different cancer tissues and their role in cancer tumorigenesis, progression and prognosis

Cancer	Status	Intratumoural microbiota	Mechanism	References
Breast cancer	Higher content	Fusobacterium nucleatum	1. Causes cancer 2. leads to poor prognosis by suppressing the immune response	[11]
	Reduction	Anaerococcus, Streptococcus, Propionibacterium	1. negatively correlated with carcinogenic immune characteristics 2. Positively correlated with T-cell activation-related genes	[12]
Ovarian cancer	Content increasing	Brucella, Chlamydia, Mycoplasma	Progressive chromosome loss and translocations cause chromosomal changes and in vitro cell transformation, promoting tumor formation	[13]
Prostate cancer	Higher content	Pseudomonas, Escherichia, Immunobacterium, Propionibacterium spp.	Induces prostatitis, enhances differentiation of prostate basal cells into ductal cells and promotes tumor formation	[14]
		Bacillus deformans	Induces prostatitis and promotes tumor formation	[15]
		Propionibacterium acnes spp.	By forming inflammation of the prostate tissue, which in turn leads to the formation of tumors	[16]
	Content increasing	Staphylococcus	Induce inflammation of the prostate tissue and promotes tumor formation	[15]
Colorectal cancer	Higher content	F. nucleic acids	1. F. nucleatum adhesion molecules bind to cell surface motifs on cancer or immune cells, resulting in downstream oncogenic or immunosuppressive signaling 2. Activation of beta-linked protein signaling; 3. resulting in low CD3 T cell density; 4. causes NK and T cell inactivation	[9] [17]
		E.coli expressing genomic island polyketide synthase (pks + E.coli)	pks + E.coli-derived alkylation of DNA by E.coli and production of DNA adducts that lead to DNA damage in colonic epithelial cells and ultimately promote cancer development	[18]
		Enterotoxin-producing Bacteroides fragilis (ETBF)	ETBF promotes cancer development by recruiting other bacteria and immune cells to the tumor site and promoting IL-17-mediated inflammation	[19]
		Fusobacterium	1. Enhances tumor cell adhesion and invasion 2. regulation of host immune response 3. Activates Toll-like receptor 4 pathway	[17]
	Presence	Bifidobacterium	Local delivery of bifidobacteria effectively stimulates STING signaling and increases crossover initiation of dendritic cells following anti-CD47 treatment, thereby influencing treatment	[20]
Pancreatic cancer	Higher content	Enterobacteriaceae, Pseudomonas spp.	Regulates metabolism of chemotherapeutic drugs, leading to chemoresistance and ultimately affecting the efficacy of treatment	[21] [22]
		Mycobacterium avium	Influences tumor progression by regulating M1 macrophage/Th1 differentiation that affects CD8 + T cell function	[22]
		Pseudoxanthomonas, Streptomyces, sucrose polyspora, Bacillus cereus	Elevates CD8 T-cell infiltration and activation, affecting prognosis	[22]
		Malassezia globosa	Promotes tumorigenesis, tumor growth and gemcitabine resistance through the mannose-binding lectin C3 axis, thereby influencing tumor formation, progression, and prognosis	[23]
Lung Cancer	Higher content	Acidovorax spp.	Associated with TP53 mutations	[24]
		Legionella	Affects metastasis of cancer	[25]
Esophageal cancer	Higher content	Lactobacillus fermentum	Can be used for cancer screening	[26]
		Campylobacter spp.	Causes inflammation and affects the prognosis of the tumor	[27]
		F. nucleic acids	As a prognostic biomarker	[28]
		Porphyromonas gingivalis	1. Promotes immune evasion of tumor cells 2. Inhibits apoptosis of epithelial cells	[29]
		Fusobacterium nucleatum	Promote tumor invasion of Treg lymphocytes in a chemokine (especially CCL20) dependent manner, promote aggressive tumor behavior, and affect tumor progression	[30]
	Ecological disorders	Fusobacterium nucleatum, Streptococcus oligosporus	Confer chemoresistance to ESCC cells through modulation of autophagy	[30]
Stomach Cancer	Higher content	Helicobacter pylori	Enhance tumor formation by promoting p53 degradation and immune escape	[31]
Bladder Cancer	Higher content	E.coli, butyrate-producing bacteria, oscillating bacilli	Associates with EMT-related genes, leading to poor prognosis	[32]
Oral cancer	Higher content	Fusobacterium nucleatum	Facilitates EMT transition and can be used to predict	[33]
		Fusobacterium nucleatum, Prevotella	Causes different types of pulp infections and promotes tumor formation	[33]
		Streptococcus peptidis	Enhances anti-tumor immune response and promotes tumor prognosis	[34]
	Ecological disorders	Mucor (especially Streptococcus), Actinomyces (especially Rhodococcus)	Promotes cancer and progression	[35]
Cervical cancer	Higher content	Fusobacterium spp.	FadA gene overexpression promotes tumor formation	[36]
		L. crispatus, L. iners	Promotes tumor formation	[36]
	Ecological disorders	Lactobacillus lactis, Serratia marcescens	Raising vaginal pH and promoting tumor formation	[37]
Endometrial cancer	Higher content	Atopobium, Porphyromonas Dialister, Peptoniphilus Ruminococcus, Anaerotruncus Anaerostipes, Treponema Bacteroides, Arthrospira	Regulates vaginal pH and promotes tumor formation	[37]
Liver cancer	Higher content	Helicobacter bifidus	Induces chronic hepatitis and promotes tumor formation	[38]
Extrahepatic bile duct cancer	Content increasing	Methanobacterium, Fusobacterium, Prevotella, Actinomyces, Neosynovia, H. pylori H	Increases cagA and vacA gene abundance and promotes tumor formation	[39]
	Reduction	Helicobacter bilis	Induces inflammation and promotes tumor formation	[40]
Bile duct cancer	Higher content	Bifidobacteriaceae, Enterobacteriaceae, Enterococcaceae	Metabolic activities can lead to the formation of carcinogens, such as ammonia and bile acids, which promote tumor formation	[41]
Gallbladder cancer	Higher content	Fusobacterium nucleatum, Escherichia coli, Enterobacter spp.	Promotes the development of gallstones and chronic cholecystitis, which in turn promotes the formation of tumors	[42]