. 2019 Aug 1;18:1533033819867354. doi: 10.1177/1533033819867354

Table 3.

Oral Bacteria and its Association With Diagnosis and Prognosis of HNSCC.

Bacterial Phylum/Genus/Species	Association in Diagnosis and Prognosis of Oral Cancer (Reference No.)
Veillonella, Fusobacterium, Prevotella, Porphyromonas, Actinomyces, Clostridium, Haemophilus, Enterobacteriaceae, and Streptococcus subspecies	Predictive diagnostic marker for premalignant lesion and OSCC⁵¹
Lactobacillus gasseri: Lactobacillus johnsonii, Lactobacillus vaginalis, Lactobacillus fermentum, Lactobacillus salivarius, and Lactobacillus rhamnosus OTUs	Increased in higher TNM stage of HNSCC⁵⁵
Streptococcus salivarius: Streptococcus vestibularis, Fusobacterium nucleatum, Prevotella oris, and Rothia mucilaginosa were highly abundant in saliva samples of HNSCC. Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, and Streptococcus mutans were positively related with risk of HNSCC. Fusobacterium periodonticum, Fusobacterium naviforme, F nucleatum_subspecies, Peptostreptococcus stomatis, Parvimonas micra and Eikenella corrodens were significantly enriched in oral cancer	Predictive diagnostic marker for HNSCC. P gingivalis, Prevotella intermedia, A actinomycetemcomitans, and F nucleatum are responsible produce volatile sulfur compounds VSCs such as genotoxic and mutagenic agent hydrogen sulfide (H₂ S) in oral cavity and methyl mercaptan (CH₃SH) in the gingival pockets that induce chronic inflammation, cell proliferation, migration, invasion and tumor angiogenesis⁶³
Pseudomonas aeruginosa	Inflammation in carcinogenesis induces DNA breaks in epithelial cells that drive chromosomal instability, LasI factor, secreted from P aeruginosa, down regulates the expression of E-cadherin that induces invasion and metastasis⁶⁵
Abundance level of genus Parvimonas	Significantly reduced in low grade (T0-T2) tumor as compared to high grade tumor (T3-T4)⁶⁰
Abundance level of the genus Actinomyces	Significantly increased in low grade (T0-T2) tumor as compared to high grade tumor (T3-T4)⁶⁰
Streptococcus, Actinomyces, Corynebacterium, Enterococcus, Micrococcus and R mucilaginosa	Significantly increased in the tongue tumor tissues⁵⁷
Level of Streptococcus, Haemophilus, Porphyromonas, and Actinomyces	Significantly decreased with the progression of OSCC⁵⁷
Abundant level of F periodonticum, P micra, Streptococcus constellatus, Haemophilus influenza, and Filifactor alocis	Progressively increased from stage 1 to stage 4 of OSCC patients; used as biomarkers for early detection and tracking for the development of OSCC. F alocis induces secretion of pro-inflammatory cytokine and induces apoptosis of gingival epithelial cells through activation of MEK ½ and caspase 3. F alocis modulates host cell response through activation of oncogenes⁷⁴
Neisseria elongata, E corrodens, Oribacterium sp. oral taxon 102, and Dialister pneumosintes	Biomarker for stage 4 of OSCC patients. Due to high alcohol dehydrogenase (ADH) activity, Neisseria produce more acetaldehyde than Streptococcus subspecies, Stomatococcus subspecies, or Moraxella subspecies. Neisseria may play an essential role in alcohol-related oral carcinogenesis⁶²
Corynebacterium and Kingella	Involved in xenobiotic biodegradation and metabolism pathways that are capable to metabolize several toxicants found in cigarette smoke⁶⁷
Actinomyces, Granulicatella, Oribacterium, and Campylobacter genera as well as Veillonella dispar, R mucilaginosa, and Haemophilus parainfluenzae	Enriched in patients with HPV-positive cancer⁶⁴
Streptococcus anginosus, Peptoniphilus, and Mycoplasma	Decreased in HPV-positive cancers⁶⁴
Streptococci such as S gordonii, S mitis, S oralis, S salivarius, S sanguinis	Possess the enzyme alcohol dehydrogenase (ADH), which metabolizes alcohol to carcinogenic acetaldehyde which induces development of oral cancer⁶³

Abbreviations: HNSCC, head and neck squamous cell carcinoma; HPV, human papilloma virus; OSCC, oral squamous cell carcinoma; VSC, volatile sulfur compounds.