TABLE 9.

Oral microbiota related to development of cancer.

No	Studies	Outcomes	References
1	Investigated oral microbiome composisition from mouthwash samples in esophageal adenocarcinoma (EAC) (n = 81) and esophageal squamos cell carcinoma (ESCC) (n = 25) using 16S rRNA gene sequencing	- Periodontal pathogen Tannerella forysthia higher risk of EAC - Commensal genus Neisseria and Streptococcus pneumoniae lower EAC risk - Increase Porphyromonas gingivalis in ESCC	Peters et al. (2017)
2	Investigated oral microbiome associated with esophageal squamos cell carcinoma (ESCC) in fasting saliva samples were collected ESCC case (n = 87), dysplasia (n = 63), and healthy controls (n = 85) using 16S rRNA sequencing	- Found that decrease carriage of genera Lautropia, Bulleidia, Catonella, Corynebacterium, Moryella, Peptococcus and Cardiobacterium in ESCC subject compared non-ESCC subject are significantly associated with an increase risk of ESCC - Higher of Prevotella and Streptococcus were also observed in the ESCC group compared to non-ESCC groups	Chen et al. (2015)
3	Investigated in case control study the relationship of oral microbiota with subsequent risk of pancreatic cancer from oral wash sampel adenocarcinoma pancreas (n = 361) and controls (n = 371) using bacterial 16S rRNA gene sequencing	- Oral pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans associated with higher risk of pancreatic cancer - Higher relative abundance of the phylum Fusobacteria and genus Leptotrichia associated decreased pancreatic cancer risk	Fan et al. (2018)
4	Cohort studies oral microbiota increase risk pancreatic cancer from saliva of patients with pancreatic cancer (n = 10) and healthy controls (n = 10) using real-time quantitative PCR (qPCR)	- The levels of N. elongata and S. mitis singnificantly decrease in patients with pancreatic cancer than healthy controls an ROC-plot AUC value of 0.90 with 96.4% sensitivity and 82.1% specificity - The level of G. adiacens significantly elevated in patients with pancreatic cancer relative to all non-cancer subjects an ROC-plot AUC value of 0.70 with 85.7% sensitivity and 55.6^ specificity	Farrell et al. (2012)
5	Characterization salivary microbiome in patients with pancreatic cancer (n = 8), other disease (n = 78), and healthy controls (n = 22) using 16S rRNA sequencing	- Found that significantly higher ratio of Leptotrichia to Porphyromonas in the saliva patients pacreatic cancer that healthy patients or patients with other disease (p < 0.0001) - Meanwhile, found that lower non significant relative abundances of Neisseria and Aggregatibacter in saliva of pancreatic cancer patients (p < 0.05)	Torres (2015)
6	Characterization oral microbiome in patients with pancreatic adenocarcinoma (n = 273) and healthy controls (n = 285) extracted from saliva samples using 16S rRNA gene was PCR amplified	- No association were detected for alpha diversity with pancreatic cancer also indication associations between specific taxa and pancreatic cancer - Increasing relative levels of Haemophilus associated with decreased odds of pancreatic cancer, while found of Enterobacteriaceae, Lachnospiraceae G7, Bacteroidaceae or Staphylococcaceae associated with increased odds of pancreatic cancer - Found the association between pancreatic cancer and the microbioal community composition (i.e., beta diversity)	Vogtmann et al. (2020)
7	Characterization oral microbiota in patients with pancreatic ductal adenocarcinoma (n = 40), intraductal papillary mucinous neoplasm (n = 39), and controls (n = 58) provided saliva sample surveyed by sequencing of the 16S rRNA microbial genes	- PDAC cases found higher levels of Firmicutes and related taxa (Bacilli, Lactobacillales, Streptococcaceae, Streptococcus, Streptococcus thermophilus) compared to controls - Gammaproteobacteria, Pasteurellales, Pasteurellaceae, Haemophilus, Haemophilus parainfluenzae; and Betaproteobacteria, Neisseriales, Neisseriaceae, Neisseria, Neisseria flaviscens has lower in PDAC but higher levels in controls - The PDAC and IPMN groups very similar in measures of alpha diversity of the oral microbiota	Olson et al. (2017)
8	Reveal the bacterial composisiton in the microbiota of tongue coating in pancreatic head carcinoma (n = 30) and healthy controls (n = 25) using 16S rRNA gene sequencing technology	- In patient with pancreatic head carcinoma overpresented microbiota than healty controls such as Leptotrichia, Fusobacterium, Rothia, Actinomyces, Corynebacterium, Atopobium, Peptostreptococcus, Catonella, Oribacterium, Filifactor, Campylobacter, Moraxella and Tannerella - Meanwhile in healthy controls increasing microbiome such as Haemophilus, Porphyromonas, and Paraprevotella	Lu et al. (2019)
9	Deep sequencing using 16S ribosomal RNA (rRNA) reveals microbiota dysbiosis of tongue coat in patient with liver carcinoma (n = 35) and healthy subjects (n = 25)	- Fusobacterium and Oribacterium increase in liver carcinoma than healthy subjects	Lu et al. (2016)
10	Variations of salivary microbiota association in patient with lung cancer ((n = 20) including squamos cell carcinoma (SCC) (n = 10) and adenocarcinoma (AC) (n = 10) and control subjects (n = 10) using 16S sequencing analysis	- Two bacterial including Capnocytophaga sp., Veillonella sp. distinguishing with SCC from control subjects ROC value 0.86 with 84.6% sensitivity and 86.7% specificity. In patients with AC distinguishing from control subjects with ROC value 0.80, sensitivity 78.6%, and specificity 80%	Yan et al. (2015)
11	Identified bacteria biomarkers associated with oral squamous cell carcinoma (OSCC) from salivary sample healthy individuals (n = 51) and oral squamous cell carcinoma (n = 197) using 16S rRNA squencing	- Fusobacteria increased significantly with the progression of oral cancer from the healthy controls (2.98%) to OSCC stage 1 (4.35%) through stage 4 (7.92%) - Fusobacterium periodonticum, Parvimonas micra, Streptococcus constellatus, Haemophilus influenza, and Filifactor alocis associated with OSCC, and progressively increased in abundance from stage 1 to stage 4	Yang et al. (2018)
12	Revealed salivary microbiome compositions in patients from non-small cell lung cancer (NSCLC) (n = 39) compared with healthy controls (n = 20) using 16S rRNA sequencing	- Phylum Firmicutes and two genera Streptococcus and Veillonella increase in NSCLC patients compared with controls	Zhang et al. (2019)
13	Case-control study oral rinse DNA sample from 190 patient with colorectal cancer used to amplify V3-V4 region of bacterial 16S rRNA gene	- Increased genus of Lactobacillus and Rothia in patient with cancer colorectal	Kato et al. (2016)
14	Investigated alteration oral microbiome linked with colorectal cancer from oral swabs, colonic mucosae and stool in individuals with colorectal cancer (n = 99), colorectal polyps (n = 32), and controls (n = 103) than sequencing using 16S rRNA gene amplicon	- An increase several ral taxa was found in colorectal cancer compared with control such as Streptococcus and Prevotella spp.	Flemer et al. (2018)
15	Case-control study examined the salivary microbiome in patients with digestive tract cancer (n = 59) and control subjects (n = 118) then sequencing using 16S rRNA gene	- Actinomyces odontolyticus, Steptococcus parasinguinis, Corynebacterium spp., Neisseria sspp.,TM7[G-1] sp., Porphyromonas gingivalis, Fusobacterium nucleatum, Neisseria elongata and Streptococcus sanguinis was more abundant in the saliva of digestive tract cancer compared with in control subjects	Kageyama et al. (2019)
16	Investigate the characteristics of oral microbiome in gastric cancer from plaques and saliva samples including individuals with gastric cancer (n = 37) and controls (n-13) then sequencing by 16S rRNA gene amplicons	- Overall increased microbial diversity in cancer patients - Oral bacteria are more complex in patients with gastric cancer than the control populations - One of the strongest risk factors for gastric cancer is detection rate of H. pylori	Sun et al. (2018)