Table 1 Characterization of the intratumoural microbiota in various cancers

Lung cancer

Genus Modestobacter³⁶

Increase

—

Genus Propionibacterium,

genus Enterobacteriaceae³⁶

Dcrease

—

Genus Blastomyces¹¹

Increase

—

Class Agaricomycetes,

genus Aspergillus¹²

Increase

—

Genus Acidovorax³⁷

Increase

Related to tumours with high TP53 mutation;

Genus Klebsiella,

genus Anaerococcus³⁷

Increase

—

Genus Acinetobacter,

genus Brevundimonas,

genus Propionibacterium³⁸

Increase

—

Phylum Cyanobacteria³⁹

Increase

—

Genus Veillonella,

genus Megasphaera⁴⁰

Increase

As the diagnostic biomarker of tumour;

Family Coriobacteriaceae,

genus Pasteurella²⁰¹

—

Related to the number of CD8 + T cells and M2 macrophages;

Species Nontypeable Haemophilus influenzae¹⁸⁸

Increase

Released IL-17C and recruited the neutrophils;

Liver cancer

Hepatitis B virus^{43,130,179,203}

Increase

Integrated viral genome into the host chromosome;

induced m6A modification of RNA

Recruited Treg cells;

Hepatitis C virus^43,204

Increase

Recruited Treg cells;

Species Helicobacter pylori^48,49,50

Increase

—

Order Gammaproteobacteria⁵³

Increase

—

Family Streptococcaceae,

genus Lactococcus⁵³

Increase

As the hallmark groups of cirrhosis hepatocellular carcinoma;

Family Enterobacteriaceae⁵⁴

Increase

—

Family Caulobacteraceae,

family Rickettsiaceae⁵⁴

Decrease

—

Species Paraburkholderia fungorum⁵⁵

Decrease

Related to antitumor activity;

Colorectal cancer

Species Enterotoxigenic Bacteroides fragilis^56,140,186

Increase

Secreted carcinogenic toxins;

initiated pro-inflammatory signalling cascade;

Genus Fusobacterium^57,58,59,182

Increase

Promoted the polarization of M2-like macrophages;

Genus Lactococcus,

genus Bacteroides,

genus Prevotella,

genus Streptococcus⁵⁹

Increase

—

Genus Pseudomonas,

genus Escherichia-Shigella⁵⁹

Decrease

—

Species Fusobacterium nucleatum^{60,141,166,167,168,174,190,199,210,211,242,248}

Increase

Related to advanced-stage tumour;

induced histone modification;

upregulated DNA methyltransferases;

inhibited autophagic process;

activated β-catenin signalling;

aggregated tumour-infiltrating myeloid cells;

activated TIGIT and CEACAM1 receptors expressed on immune cells;

induced EMT;

upregulated ICAM1 and promoted the adhesion of cancer cells to endothelial cells;

Genus Bifidobacterium,

genus Romboutsia⁶²

Increase

Related to left-sided colon cancers;

Genus Haemophilus,

genus Veillonella⁶²

Increase

Related to right-sided colon cancers;

Phylum Ascomycota

Class Malasseziomycetes⁶⁵

Increase

—

Class Saccharomycetes,

class Pneumocystidomycetes⁶⁵

Dcrease

—

Species Escherichia coli^140,249

Increase

Secreted carcinogenic toxins;

related to metastasis;

Species Enteropathogenic Escherichia coli¹⁴⁴

Increase

Disrupted mechanisms of DNA mismatch repair;

Species Hungatella hathewayi¹⁶⁸

—

Upregulated DNA methyltransferases;

Genus Akkermansia¹⁹⁴

—

Increased IL-17 production and B cell infiltration;

Genus Candida¹¹

Increase

Involved in the downregulation of genes mediating cellular adhesion;

Gastric cancer

Species Helicobacter pylori^{68,69,76,145,161,162,212,213,214}

Increase

Related to early-stage of tumours;

disrupted DNA mismatch repair mechanisms;

inducted abnormal DNA methylation;

activated CEACAM1 on immune cells;

upregulated PD-L1 expression;

Genus Prevotella,

genus Streptococcus,

genus Veillonella,

genus Haemophilus

genus Neisseria⁷³

Increase

—

Genus Helicobacter^73,227

Decrease

Metabolic regulation;

Genus Lactobacillus^74,227

Increase

Related to tumour progression;

metabolic regulation;

Phylum Nitrospirae,

family Lachnospiraceae,

genus Escherichia-Shigella,

species Burkholderia fungorum⁷⁴

Increase

Related to tumour progression;

Genus Oceanobacter,

genus Methylobacterium,

genus Syntrophomonas⁷⁵

Increase

—

Species Propionibacterium acnes,

species Prevotella copri⁷⁶

Increase

Related to early-stage of tumours;

Phylum TM7,

genus Porphyromonas,

genus Neisseria

species Streptococcus sinensis⁷⁷

Decrease

Related to benign gastric disease;

Family Lachnospiraceae,

species Lactobacillus coleohominis⁷⁷

Increase

Related to malignant gastric disease;

Epstein-Barr virus^70,71,72

Increase

Related to DNA hypermethylation;

Order Clostridium,

family Comamonadaceae,

genus Moryella,

genus Vibro,

genus Paludibacter,

genus Agrobacterium³⁰

Increase

Monitor the risk of gastric cancer development;

Species Kytococcus sedentarius,

species Actinomyces oris¹⁶³

Increase

Inducted abnormal DNA methylation;

Breast cancer

Genus Pseudomonas,

genus Proteus⁸¹

Increase

—

Species Methylobacterium radiotolerans^82,83

Increase

—

Species Sphingomonas yanoikuyae⁸²

Decrease

—

Genus Methylobacterium⁸⁴

Decrease

—

Genus Cladosporium¹²

Increase

—

Genus Lactobacillus^85,225

Increase

Metabolic regulation;

enhanced the resistance of tumour cells to flow shear stress;

Genus Streptococcus,

genus Staphylococcus⁸⁵

Increase

Enhanced the resistance of tumour cells to flow shear stress;

Family Streptococcaceae⁸⁸

Increase

—

Genus Bosea⁸⁸

Increase

Related to tumour progression;

Species Escherichia coli,

species Staphylococcus epidermis¹⁴³

Increase

Caused double-stranded DNA breaks;

Genus Fusobacterium,

genus Atopobium,

genus Hydrogenophaga,

genus Gluconacetobacter²²⁵

Increase

Metabolic regulation;

Species Enterotoxigenic Bacteroides fragilis²⁴⁶

Increase

Enhanced stemness potential and metastatic progression;

Species Fusobacterium nucleatum^33,252

Increase

Related to metastasis;

Pancreatic cancer

Phylum Proteobacteria⁹¹

Increase

—

Species Helicobacter pylori^92,93

Increase

Related to activation of molecular pathways for tumour growth and progression;

Genus Pseudomonas^91,94

Increase

Related to carcinogenesis;

Genus Elizabethkingia⁹¹

Increase

—

Genus Acinetobacter,

genus Sphingopyxis⁹⁴

Increase

Related to carcinogenesis;

Genus Malassezia⁹⁵

Increase

—

Oral cancer

Genus Fusobacterium^101,112

Increase

—

Species Fusobacterium nucleatum^142,229

Increase

Caused double-stranded DNA breaks;

Promoted GLUT1 upregulation and lactic acid accumulation;

Species Porphyromonas gingivalis^{102,103,104,105,154,155,244}

Increase

Related to the formation of DNA adducts or the inhibition of DNA repair enzymes;

Related to the expression of EMT-related transcription factors;

Genus Prevotella¹⁰⁶

Icrease

—

Species Prevotella intermedia¹⁰⁷

Increase

Related to carcinogenesis;

Species Treponema denticola^108,109

Increase

—

Species Streptococcus anginosus^110,111,155

Increase

Related to the formation of DNA adducts or the inhibition of DNA repair enzymes;

Genus Streptococcus¹¹²

Decrease

—

Species Pseudomonas aeruginosa,

Campylobacter sp. Oral taxon 44¹¹³

Increase

—

Human papillomavirus⁹⁸

Increase

—

Epstein-Barr virus⁹⁹

Increase

—

Herpes Simplex Virus Type 1¹⁰⁰

Increase

—

Species Candida albicans,

species Candida etchellsii,

species Hannaella luteola-like¹¹⁴

Increase

—

Head-and-neck squamous cell carcinomas

Genus Parvimonas¹¹⁶

Increase

—

Genus Actinomyces¹¹⁶

Decrease

—

Human papillomavirus types 16^117,134

Increase

Inhibited the cGas-STING pathway;

Oesophageal cancer

Species Campylobacter conisus¹⁸⁹

Increase

Upregulated PRRs and aggregated IFI16 inflammasome;

Nasopharyngeal carcinoma

Genus Corynebacterium,

genus Staphylococcus²⁸

Increase

—

Epstein-Barr virus^119,217

Increase

Downregulated IDO expression;

Ovarian carcinoma

Phylum Aquificae,

phylum Planctomycetes¹²⁰

Increase

—

Phylum Crenarchaeota¹²⁰

Decrease

—

Human papillomavirus types 16, 18, and 45¹²¹

Related to advanced-stage tumours;

Endometrial cancer

Genus Bacteroides,

genus Faecalibacterium¹²²

Increase

—

Genus Staphylococcus,

genus Blautia,

genus Parabacteroides¹²²

Decrease

—

Cervical cancer

Genus Gardnerella,

genus Prevotella,

genus Streptococcus,

genus Atopobium²²⁶

Increase

Metabolic regulation;

Human papillomavirus^{131,205,208,209}

Increase

Integrated viral genome into the host chromosome;

recruited Treg cells;

inhibited cytotoxic T and NK cell activation;

upregulated PD-L1 expression;

Prostatic cancer

Species Cutibacterium acnes^123,124

Increase

—

Species Staphylococcus aureus²⁰²

Increase

Recruited Treg cells;

Bladder cancer

Species Escherichia coli,

species Butyrate-producing bacteria SM4/1,

a species of Oscillatoria²⁴³

Increase

Related to the expression of EMT-related genes;

Pituitary neuroendocrine tumour

Order Clostridiales,

family Fusobacteriaceae,

family Tissierellaceae,

family Aerococcaceae,

family Corynebacteriaceae,

family S24-7,

F16¹²⁵

Increase

Related to different clinical phenotypes of tumour;

Burkitt’s lymphoma

Epstein-Barr virus¹²⁶

Increase

—

Hodgkin’s lymphoma

Epstein-Barr virus¹²⁶

Increase

—

NK cell and T cell lymphomas

Epstein-Barr virus¹²⁶

Increase

—

Human T-lymphotropic virus type 1¹³⁹

Increase

Inhibited DNA repair pathway.

Lymphocytic leukaemia

Human endogenous retroviruses¹¹⁸

Increase

—