Oral Microbiome in Nonsmoker Patients with Oral Cavity Squamous Cell Carcinoma, Defined by Metagenomic Shotgun Sequencing
Objectives: Smoking is the commonest cause of oral cavity squamous cell carcinoma (OC-SCC), but the etiology of OC-SCC in nonsmokers is unknown. Our primary goal was to use metagenomic shotgun sequencing (MSS) to define the taxonomic composition and functional potential of oral metagenome in nonsmokers with OC-SCC. Methods: We conducted a case"“control study with 42 OC-SCC case and 45 control nonsmokers. MSS was performed on DNA extracted from mouthwash samples. Taxonomic analysis and pathway analysis were done using MetaPhlAn2 and HUMAnN2, respectively. Statistical difference was determined using the Mann"“Whitney test controlling false discovery rate. Results: There was no significant difference in age, sex, race, or alcohol consumption between OC-SCC and control patients. There was a significant difference in beta diversity between OC-SCC and controls. At the phylum level, Bacteroidetes and Synergistetes were overly represented in OC-SCC while Actinobacteria and Firmicutes were overly represented in controls. At the genus level, Fusobacterium was overly represented in OC-SCC compared with controls, while Corynebacterium, Streptococcus, Actinomyces, Cryptobacterium, and Selenomonas were overly represented in controls. Bacterial pathway analysis identified overrepresentation in OC-SCC of pathways related to metabolism of flavin, biotin, thiamin, heme, sugars, fatty acids, peptidoglycans, and tRNA and overrepresentation of nucleotides and essential amino acids in controls. Conclusions: The oral microbiome in nonsmoker patients with OC-SCC is significantly different from that of nonsmoker control patients in taxonomic compositions and functional potentials. Our study"™s MSS findings matched with previous 16S-based methods in taxonomic differentiation but varied greatly in functional differentiation of microbiomes in OC-SCC and controls.
Progressive dysbiosis of human orodigestive microbiota along the sequence of gastroesophageal reflux, Barrett's esophagus and esophageal adenocarcinoma
The incidence of esophageal adenocarcinoma (EA) has drastically increased in the United States since 1970s for unclear reasons. We hypothesized that the widespread usage of antibiotics has increased the procarcinogenic potential of the orodigestive microbiota along the sequence of gastroesophageal reflux (GR), Barrett's esophagus (BE) and EA phenotypes. This case control study included normal controls (NC) and three disease phenotypes GR, BE and EA. Microbiota in the mouth, esophagus, and stomach, and rectum were analyzed using 16S rRNA gene sequencing. Overall, we discovered 44 significant pairwise differences in abundance of microbial taxa between the four phenotypes, with 12 differences in the mouth, 21 in the esophagus, two in the stomach, and nine in the rectum. Along the GRâ†’BEâ†’EA sequence, oral and esophageal microbiota were more diversified, the dominant genus Streptococcus was progressively depleted while six other genera Atopobium, Actinomyces, Veillonella, Ralstonia, Burkholderia and Lautropia progressively enriched. In NC, Streptococcus appeared to control populations of other genera in the foregut via numerous negative and positive connections, while in disease states, the rich network was markedly simplified. Inferred gene functional content showed a progressive enrichment through the stages of EA development in genes encoding antibiotic resistance, ligands of Toll-like and NOD-like receptors, nitrate-nitrite-nitric oxide pathway and acetaldehyde metabolism. The orodigestive microbiota is in a progressive dysbiotic state along the GR-BE-EA sequence. The increasing dysbiosis and antibiotic and procarcinogenic genes in the disease states warrants further study to define their roles in EA pathogenesis.
Prospective study of oral microbiome and gastric cancer risk among Asian, African American and European American populations
Colonization of specific bacteria in the human mouth was reported to be associated with gastric cancer risk. However, previous studies were limited by retrospective study designs and low taxonomic resolutions. We performed a prospective case-control study nested within three cohorts to investigate the relationship between oral microbiome and gastric cancer risk. Shotgun metagenomic sequencing was employed to characterize the microbiome in prediagnostic buccal samples from 165 cases and 323 matched controls. Associations of overall microbial richness and abundance of microbial taxa, gene families and metabolic pathways with gastric cancer risk were evaluated via conditional logistic regression. Analyses were performed within each cohort, and results were combined by meta-analyses. We found that overall microbial richness was associated with decreased gastric cancer risk, with an odds ratio (OR) per standard deviation (SD) increase in Simpson's reciprocal index of 0.77 (95% confidence interval [CI]Â =Â 0.61-0.99). Nine taxa, 38 gene families and six pathways also showed associations with gastric cancer risk at Pâ€‰<â€‰.05. Neisseria mucosa and Prevotella pleuritidis were enriched, while Mycoplasma orale and Eubacterium yurii were depleted among cases with ORs and 95% CIs per SD increase in centered log-ratio transformed taxa abundance of 1.31 (1.03-1.67), 1.26 (1.00-1.57), 0.74 (0.59-0.94) and 0.80 (0.65-0.98), respectively. The top two gene families (PÂ =Â 3.75â€‰Ã—â€‰10-4 and 3.91â€‰Ã—â€‰10-4 ) and pathways (PÂ =Â 1.75â€‰Ã—â€‰10-3 and 1.53â€‰Ã—â€‰10-3 ) associated with gastric cancer were related to the decreased risk and are involved in hexitol metabolism. Our study supports the hypothesis that oral microbiota may play a role in gastric cancer etiology.
Oral and gastric microbiome in relation to gastric intestinal metaplasia
Evidence suggests that Helicobacter pylori plays a role in gastric cancer (GC) initiation. However, epidemiologic studies on the specific role of other bacteria in the development of GC are lacking. We conducted a case-control study of 89 cases with gastric intestinal metaplasia (IM) and 89 matched controls who underwent upper gastrointestinal endoscopy at three sites affiliated with NYU Langone Health. We performed shotgun metagenomic sequencing using oral wash samples from 89 case-control pairs and antral mucosal brushing samples from 55 case-control pairs. We examined the associations of relative abundances of bacterial taxa and functional pathways with IM using conditional logistic regression with and without elastic-net penalty. Compared with controls, oral species Peptostreptococcus stomatis, Johnsonella ignava, Neisseria elongata and Neisseria flavescens were enriched in cases (odds ratios [ORs]Â =Â 1.29-1.50, PÂ =Â .004-.01) while Lactobacillus gasseri, Streptococcus mutans, Sâ€‰parasanguinis and Sâ€‰sanguinis were under-represented (ORsÂ =Â 0.66-0.76, PÂ =Â .006-.042) in cases. Species Jâ€‰ignava and Filifactor alocis in the gastric microbiota were enriched (ORsÂ =Â 3.27 and 1.43, PÂ =Â .005 and .035, respectively), while Sâ€‰mutans, Sâ€‰parasanguinis and Sâ€‰sanguinis were under-represented (ORsÂ =Â 0.61-0.75, PÂ =Â .024-.046), in cases compared with controls. The lipopolysaccharide and ubiquinol biosynthesis pathways were more abundant in IM, while the sugar degradation pathways were under-represented in IM. The findings suggest potential roles of certain oral and gastric microbiota, which are correlated with regulation of pathways associated with inflammation, in the development of gastric precancerous lesions.
Case control study comparing the HPV genome in patients with oral cavity squamous cell carcinoma to normal patients using metagenomic shotgun sequencing
The aim of this study was to carry out a case control study comparing the HPV genome in patients with oral cavity squamous cell carcinoma (OC-SCC) to normal patients using metagenomic shotgun sequencing. We recruited 50 OC-SCC cases which were then matched with a control patient by age, gender, race, smoking status and alcohol status. DNA was extracted from oral wash samples from all patients and whole genome shotgun sequencing performed. The raw sequence data was cleaned, reads aligned with the human genome (GRCH38), nonhuman reads identified and then HPV genotypes identified using HPViewer. In the 50 patients with OC-SCC, the most common subsite was tongue in 26 (52%). All patients were treated with primary resection and neck dissection. All but 2 tumors were negative on p16 immunohistochemistry. There were no statistically significant differences between the cases and controls in terms of gender, age, race/ethnicity, alcohol drinking, and cigarette smoking. There was no statistically significant difference between the cancer samples and control samples in the nonhuman DNA reads (medians 4,228,072 vs. 5,719,715, P valueâ€‰=â€‰0.324). HPV was detected in 5 cases (10%) of OC-SCC (genotypes 10, 16, 98) but only 1 tumor sample (genotype 16) yielded a high number of reads to suggest a role in the etiology of OC-SCC. HPV was detected in 4 control patients (genotypes 16, 22, 76, 200) but all had only 1-2 HPV reads per human genome. Genotypes of HPV are rarely found in patients with oral cancer.
Intragastric Balloon Improves Steatohepatitis and Fibrosis [Case Report]
Obesity is a major risk factor for nonalcoholic steatohepatitis (NASH). Although weight loss has been shown to reverse histologic features of NASH, lifestyle intervention alone is often challenging and unfeasible. In this case report, we discuss the effects of intragastric balloon (IGB) therapy on steatosis, fibrosis, and portal pressures. We also demonstrate that improvement in histologic features persist at least 6 months after IGB removal. Although there are little data thus far to support IGB therapy in the treatment of NASH, our case provides evidence of the potential benefit of IGB on improving metabolic parameters and markers of liver fibrosis.
The association between smoking and gut microbiome in Bangladesh
INTRODUCTION/BACKGROUND:Epidemiological studies that investigate alterations in the gut microbial composition associated with smoking are lacking. This study examined the composition of the gut microbiome in smokers compared with non-smokers. METHODS:Stool samples were collected in a cross-sectional study of 249 participants selected from the Health Effects of Arsenic Longitudinal Study (HEALS) in Bangladesh. Microbial DNA was extracted from the fecal samples and sequenced by 16S rRNA gene sequencing. The associations of smoking status and intensity of smoking with the relative abundance or the absence and presence of individual bacterial taxon from phylum to genus levels were examined. RESULTS:The relative abundance of bacterial taxa along the Erysipelotrichi-to-Catenibacterium lineage was significantly higher in current smokers compared to never smokers. The odds ratio comparing the mean relative abundance in current smokers with that in never smokers was 1.91 (95% confidence interval [CI] = 1.36 to 2.69) for the genus Catenibacterium and 1.89 (95% CI = 1.39 to 2.56) for the family Erysipelotrichaceae, the order Erysipelotrichale, and the class Erysipelotrichi ((FDR-adjusted p-values = 0.0008 to 0.01). A dose-response association was observed for each of these bacterial taxa. The presence of Alphaproteobacteria was significantly greater comparing current with never smokers (OR = 4.85, FDR-adjusted p-values = 0.04). CONCLUSIONS:Our data in a Bangladeshi population are consistent with evidence of an association between smoking status and dosage with change in the gut bacterial composition. IMPLICATIONS/CONCLUSIONS:This study for the first time examined the relationship between smoking and the gut microbiome composition. The data suggest that smoking status may play an important role in the composition of the gut microbiome, especially among individuals with higher levels of tobacco exposure.
Reply to Kenyon, "Are Differences in the Oral Microbiome Due to Ancestry or Socioeconomics?"
Long-Term Effects of Early-Life Antibiotic Exposure on Resistance to Subsequent Bacterial Infection
Early-life antibiotic exposure may provoke long-lasting microbiota perturbation. Since a healthy gut microbiota confers resistance to enteric pathogens, we hypothesized that early-life antibiotic exposure would worsen the effects of a bacterial infection encountered as an adult. To test this hypothesis, C57BL/6 mice received a 5-day course of tylosin (macrolide), amoxicillin (Î²-lactam), or neither (control) early in life and were challenged with Citrobacter rodentium up to 80â€‰days thereafter. The early-life antibiotic course led to persistent alterations in the intestinal microbiota and even with pathogen challenge 80â€‰days later worsened the subsequent colitis. Compared to exposure to amoxicillin, exposure to tylosin led to greater disease severity and microbiota perturbation. Transferring the antibiotic-perturbed microbiota to germfree animals led to worsened colitis, indicating that the perturbed microbiota was sufficient for the increased disease susceptibility. These experiments highlight the long-term effects of early-life antibiotic exposure on susceptibility to acquired pathogens.IMPORTANCE The gastrointestinal microbiota protects hosts from enteric infections; while antibiotics, by altering the microbiota, may diminish this protection. We show that after early-life exposure to antibiotics host susceptibility to enhanced Citrobacter rodentium-induced colitis is persistent and that this enhanced disease susceptibility is transferable by the antibiotic-altered microbiota. These results strongly suggest that early-life antibiotics have long-term consequences on the gut microbiota and enteropathogen infection susceptibility.
Cigarette smoking and oral microbiota in low-income and African-American populations
BACKGROUND:Cigarette smoking is a common risk factor for diseases and cancers. Oral microbiota is also associated with diseases and cancers. However, little is known about the impact of cigarette smoking on the oral microbiota, especially among ethnic minority populations. METHODS:We investigated cigarette smoking in relationship with the oral microbiota in a large population of predominately low-income and African-American participants. Mouth rinse samples were collected from 1616 participants within the Southern Community Cohort Study, including 592 current-smokers, 477 former-smokers and 547 never-smokers. Oral microbiota was profiled by 16S ribosomal RNA gene deep sequencing. RESULTS:<0.05. The differences in the overall microbial composition and abundance/prevalence of most taxa were observed among both African-Americans and European-Americans. Meanwhile, such differences were not observed between former-smokers and never-smokers. CONCLUSION/CONCLUSIONS:Smoking has strong impacts on oral microbial community, which was recovered after smoking cessation.