The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the ho...The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the homeostatic balanceexisting between the oral microbiota and host may be disturbed and result in the development of diseases. Numerousobservations have suggested that small RNAs are key regulators of bacterial pathogenesis and bacteria-host interactions.Further, bacterial small RNAs are considered to be promising biomarkers for the development of novel, and efficacioustherapies for oral dysbiosis. Mechanistic insights into how oral pathogens communicate with other bacteria or host cellsin oral cancers via small RNAs are hot topics of research. Current studies also have begun to elucidate the key role oforal microbiota in the development of systemic diseases. This article discusses existing findings and nascent mechanismsgoverning the small RNA-based interactions between oral microbiota and associated diseases. The knowledge of suchinteractions is key in planning approaches to reverse dysbiosis to achieve health.展开更多
Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have es...Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have established associations between them.Dysbiosis of oral microbiota has already been established as a major factor contributing to periodontitis.Recent emerging epidemiological evidence and the detection of oral microbiota in genitourinary organs indicate the presence of an oral-genitourinary axis and oral microbiota may be involved in the pathogenesis of genitourinary cancers.Therefore,oral microbiota provides the bridge between periodontitis and genitourinary cancers.We have carried out this narrative review which summarizes epidemiological studies exploring the association between periodontitis and genitourinary cancers.We have also highlighted the current evidence demonstrating the capacity of oral microbiota to regulate almost all hallmarks of cancer,and proposed the potential mechanisms of oral microbiota in the development of genitourinary cancers.展开更多
Oral microbiota is an important part of the human microbiota.Oral microbes can be colonized into the intestine in various ways.Oral microbiota is associated with a variety of oral diseases.Recently,increasing evidence...Oral microbiota is an important part of the human microbiota.Oral microbes can be colonized into the intestine in various ways.Oral microbiota is associated with a variety of oral diseases.Recently,increasing evidence has shown that the oral microbiota is closely related to the physical state of humans,such as diabetes,obesity,and cancer.In the future,oral microbiota will become a new target for improving the physical state of humans.展开更多
Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bac...Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts（n530）; patients with periodontal disease without a history of BP therapy（Control, n510）, patients with periodontal disease having history of BP therapy but without ONJ（BP, n55） and patients with BRONJ（BRONJ, n515）. Denaturing gradient gel electrophoresis of polymerase chain reaction（PCR）-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ（71.6%）, BP（70.3%） and Control（59.1%）. Significant differences（P,0.05） in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay（ELISA）results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.展开更多
Background: Periodontal diseases comprise a wide range of inflammatory conditions that affect the supporting structures of the teeth, and may lead to severe periodontal destruction and even tooth loss.?Streptococcus s...Background: Periodontal diseases comprise a wide range of inflammatory conditions that affect the supporting structures of the teeth, and may lead to severe periodontal destruction and even tooth loss.?Streptococcus salivarius K12 (S. salivarius K12), one of oral probiotics, has been reported to be able to inhibit various potentially deleterious bacteria. This study was the first time to investigate the effects of S. salivarius K12 on ligature-induced periodontitis in mice. Methods: A silk ligature was tied around the second left maxillary molar to establish the model of periodontitis, and then, mice in group S. salivarius K12 were administered with S. salivarius K12 (2 x 109 CFU) twice daily for 30 d, the others were treated with isopyknic water. Results: Administration with S. salivarius K12 markedly decreased the anaerobic bacteria accumulation on the teeth, and it also considerably alleviated periodontitis-induced alveolar bone resorption and attachment loss. Moreover, S. salivarius K12 administration increased the relative species abundance of Gram-positive bacterium in oral cavity while decreased Gram-negative bacterium, as well as the diversity of the bacterial community. Conclusion: Oral administration of the probiotic S. salivarius K12 may mitigate the alveolar bone resorption and attachment loss of periodontitis by modulating the oral microbiota.展开更多
The polymorphic microbiome has been defined as one of the“Hallmarks of Cancer”.Extensive studies have now uncovered the role of oral microbiota in cancer development and progression.Bacteria,fungi,archaea,and viruse...The polymorphic microbiome has been defined as one of the“Hallmarks of Cancer”.Extensive studies have now uncovered the role of oral microbiota in cancer development and progression.Bacteria,fungi,archaea,and viruses in the oral cavity interact dynamically with the oral microenvironment to maintain the oral micro-ecological homeostasis.This complex interaction is influenced by many factors,such as maternal transmission,personal factors and environmental factors.Dysbiosis of oral microbiota can disturbed this host-microbiota interaction,leading to systemic diseases.Numerous studies have shown the potential associations between oral microbiota and a variety of cancers.However,the underlying mechanisms and therapeutic insights are still poorly understood.In this review,we mainly focus on the following aspects:(1)the factors affect oral microbiota composition and function;(2)the interaction between microenvironment and oral microbiota;(3)the role of multi-kingdom oral microbiota in human health;(4)the potential underlying mechanisms and therapeutic benefits of oral microbiota against cancer.Finally,we aim to describe the impact of oral microbiota on cancer progression and provide novel therapeutic insights into cancer prevention and treatment by targeting oral microbiota.展开更多
In this work,microbiologically influenced corrosion(MIC)of 316 L stainless steel(SS)caused by oral microbiota was investigated with HOMINGS 16 S rRNA gene sequencing technology,and electrochemical and surface analysis...In this work,microbiologically influenced corrosion(MIC)of 316 L stainless steel(SS)caused by oral microbiota was investigated with HOMINGS 16 S rRNA gene sequencing technology,and electrochemical and surface analysis techniques.The results showed that oral microbiota from different subjects developed multi-species biofilms with significant differences in structure and composition of bacteria strains on the316 L SS coupons.In the presence of oral microbiota,more severe pitting corrosion and faster dissolution of metallic ions including Ni and Cr were observed.The biofilm considerably decreased the pitting potential of 316 L SS from 1268.0±29.1 mV vs.SCE(abiotic control)to less than 500 mV vs.SCE.The corrosion current density in the presence of oral microbiota from subject 1(115.3±83.3 nA cm^(-2))and subject 2(184.4±162.0 nA cm^(-2))was at least 4 times more than that in the abiotic medium(28.0±2.3 nA cm^(-2)).The electroactive microorganisms with the potential to facilitate corrosion via extracellular electron transfer found in oral microbiota may be mainly responsible for the accelerated corrosion.展开更多
Frailty is a critical intermediate status of the aging process with a multidimensional and multisystem nature and at higher risk for adverse health-related outcomes,including falls,disability,hospitalizations,institut...Frailty is a critical intermediate status of the aging process with a multidimensional and multisystem nature and at higher risk for adverse health-related outcomes,including falls,disability,hospitalizations,institutionalization,mortality,dementia,and Alzheimer’s disease.Among different frailty phenotypes,oral frailty has been recently suggested as a novel construct defined as a decrease in oral function with a coexisting decline in cognitive and physical functions.We briefly reviewed existing evidence on operational definitions of oral frailty,assessment and screening tools,and possible relationships among oral frailty,oral microbiota,and Alzheimer’s disease neurodegeneration.Several underlying mechanism may explain the oral health-frailty links including undernutrition,sarcopenia linked to both poor nutrition and frailty,psychosocial factors,and the chronic inflammation typical of oral disease.Oral microbiota may influence Alzheimer’s disease risk through circulatory or neural access to the brain and the interplay with periodontal disease,often causing tooth loss also linked to an increased Alzheimer’s disease risk.On this bases,COR388,a bacterial protease inhibitor targeting Porphyromonas gingivalis implicated in periodontal disease,is now being tested in a double-blind,placebocontrolled Phase II/III study in mild-to-moderate Alzheimer’s disease.Therefore,oral status may be an important contributor to general health,including Alzheimer’s disease and latelife cognitive disorders,suggesting the central role of preventive strategies targeting the novel oral frailty phenotype and including maintenance and improvement of oral function and nutritional status to reduce the burden of both oral dysfunction and frailty.展开更多
The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was perf...The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients.Eight patients with head and neck cancers were involved in this study.For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy.A total of 147 232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis,representing 3 460 species level operational taxonomic units(OTUs) and 140 genus level taxa.Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics.Moreover,the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves.This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.展开更多
BACKGROUND Microbiota profiles differ between patients with pancreatic cancer and healthy people,and understanding these differences may help in early detection of pancreatic cancer.Saliva sampling is an easy and cost...BACKGROUND Microbiota profiles differ between patients with pancreatic cancer and healthy people,and understanding these differences may help in early detection of pancreatic cancer.Saliva sampling is an easy and cost-effective way to determine microbiota profiles compared to fecal and tissue sample collection.AIM To investigate the saliva microbiome distribution in patients with pancreatic adenocarcinoma(PDAC)and the role of oral microbiota profiles in detection and risk prediction of pancreatic cancer.METHODS We conducted a prospective study of patients with pancreatic cancer(n=41)and healthy individuals(n=69).Bacterial taxa were identified by 16S ribosomal ribonucleic acid gene sequencing,and a linear discriminant analysis effect size algorithm was used to identify differences in taxa.Operational taxonomic unit values of all selected taxa were converted into a normalized Z-score,and logistic regressions were used to calculate risk prediction of pancreatic cancer.RESULTS Compared with the healthy control group,carriage of Streptococcus and Leptotrichina(z-score)was associated with a higher risk of PDAC[odds ratio(OR)=5.344,95%confidence interval(CI):1.282-22.282,P=0.021 and OR=6.886,95%CI:1.423-33.337,P=0.016,respectively].Veillonella and Neisseria(z-score)were considered a protective microbe that decreased the risk of PDAC(OR=0.187,95%CI:0.055-0.631,P=0.007 and OR=0.309,95%CI:0.100-0.952,P=0.041,respectively).Among the patients with PDAC,patients reporting bloating have a higher abundance of Porphyromonas(P=0.039),Fusobacterium(P=0.024),and Alloprevotella(P=0.041);while patients reporting jaundice had a higher amount of Prevotella(P=0.008);patients reporting dark brown urine had a higher amount of Veillonella(P=0.035).Patients reporting diarrhea had a lower amount of Neisseria and Campylobacter(P=0.024 and P=0.034),and patients reporting vomiting had decreased Alloprevotella(P=0.036).CONCLUSION Saliva microbiome was able to distinguish patients with pancreatic cancer and healthy individuals.Leptotrichia may be specific for patients living in Sichuan Province,southwest China.Symptomatic patients had different bacteria profiles than asymptomatic patients.Combined symptom and microbiome evaluation may help in the early detection of pancreatic cancer.展开更多
基金supported by the National Natural Science Foundation of China(Nos.82071104 and 81900988)the Clinical Research Program of 9th People’s Hospital,Shanghai Jiao Tong University School of Medicine(No.JYLJ201908).
文摘The oral microbiota is a vital part of the human microbiota that functions in various physiological processes and ishighly relevant to cancers and other diseases. With the alterations of host immune competence, the homeostatic balanceexisting between the oral microbiota and host may be disturbed and result in the development of diseases. Numerousobservations have suggested that small RNAs are key regulators of bacterial pathogenesis and bacteria-host interactions.Further, bacterial small RNAs are considered to be promising biomarkers for the development of novel, and efficacioustherapies for oral dysbiosis. Mechanistic insights into how oral pathogens communicate with other bacteria or host cellsin oral cancers via small RNAs are hot topics of research. Current studies also have begun to elucidate the key role oforal microbiota in the development of systemic diseases. This article discusses existing findings and nascent mechanismsgoverning the small RNA-based interactions between oral microbiota and associated diseases. The knowledge of suchinteractions is key in planning approaches to reverse dysbiosis to achieve health.
基金the Zhongnan Hospital of Wuhan University Science,Technology and Innovation Seed Fund(No.znpy2019011)the Fundamental Research Funds for the Central Universities(No.2042020kf0130)+1 种基金the Nature Science Foundation of Hubei Province(No.2019FFB03902)the Health Commission of Hubei Province Scientific Research Project(No.WJ2019H035).
文摘Periodontitis has been proposed as a novel risk factor of genitourinary cancers:although periodontitis and genitourinary cancers are two totally distinct types of disorders,epidemiological and clinical studies,have established associations between them.Dysbiosis of oral microbiota has already been established as a major factor contributing to periodontitis.Recent emerging epidemiological evidence and the detection of oral microbiota in genitourinary organs indicate the presence of an oral-genitourinary axis and oral microbiota may be involved in the pathogenesis of genitourinary cancers.Therefore,oral microbiota provides the bridge between periodontitis and genitourinary cancers.We have carried out this narrative review which summarizes epidemiological studies exploring the association between periodontitis and genitourinary cancers.We have also highlighted the current evidence demonstrating the capacity of oral microbiota to regulate almost all hallmarks of cancer,and proposed the potential mechanisms of oral microbiota in the development of genitourinary cancers.
基金the National Key R&D Program of China(2018YFD0400204)the Key International S&T Cooperation Program of China(2016YFE113700)+3 种基金the European Union’s Horizon 2020 Research and Innovation Program(633589)the National Natural Science Foundation of China(81471396,81871095)SME Technology Innovation Fund Program funded by Hebei science and Technology Office(No.000218018/2015-00337)The Introduction of Foreign Intelligence Program funded by Hebei Provincial Department of Human Resource and Social security(000218296/2005-00593).
文摘Oral microbiota is an important part of the human microbiota.Oral microbes can be colonized into the intestine in various ways.Oral microbiota is associated with a variety of oral diseases.Recently,increasing evidence has shown that the oral microbiota is closely related to the physical state of humans,such as diabetes,obesity,and cancer.In the future,oral microbiota will become a new target for improving the physical state of humans.
基金supported by NIH grants CA172894, CA180277, DE020891New York University Research Funds
文摘Bacterial biofilms have emerged as potential critical triggers in the pathogenesis of bisphosphonate（BP）-related osteonecrosis of the jaw（ONJ） or BRONJ. BRONJ lesions have shown to be heavily colonized by oral bacteria, most of these difficult to cultivate and presents many clinical challenges. The purpose of this study was to characterize the bacterial diversity in BRONJ lesions and to determine host immune response. We examined tissue specimens from three cohorts（n530）; patients with periodontal disease without a history of BP therapy（Control, n510）, patients with periodontal disease having history of BP therapy but without ONJ（BP, n55） and patients with BRONJ（BRONJ, n515）. Denaturing gradient gel electrophoresis of polymerase chain reaction（PCR）-amplified 16 S r RNA gene fragments revealed less bacterial diversity in BRONJ than BP and Control cohorts. Sequence analysis detected six phyla with predominant affiliation to Firmicutes in BRONJ（71.6%）, BP（70.3%） and Control（59.1%）. Significant differences（P,0.05） in genera were observed, between Control/BP, Control/BRONJ and BP/BRONJ cohorts. Enzyme-linked immunosorbent assay（ELISA）results indicated that the levels of myeloperoxidase were significantly lower, whereas interleukin-6 and tumor necrosis factor-alpha levels were moderately elevated in BRONJ patients as compared to Controls. PCR array showed significant changes in BRONJ patients with downregulation of host genes, such as nucleotide-binding oligomerization domain containing protein 2, and cathepsin G, the key modulators for antibacterial response and upregulation of secretory leukocyte protease inhibitor, proteinase 3 and conserved helix–loop–helix ubiquitous kinase. The results suggest that colonization of unique bacterial communities coupled with deficient innate immune response is likely to impact the pathogenesis of ONJ.
文摘Background: Periodontal diseases comprise a wide range of inflammatory conditions that affect the supporting structures of the teeth, and may lead to severe periodontal destruction and even tooth loss.?Streptococcus salivarius K12 (S. salivarius K12), one of oral probiotics, has been reported to be able to inhibit various potentially deleterious bacteria. This study was the first time to investigate the effects of S. salivarius K12 on ligature-induced periodontitis in mice. Methods: A silk ligature was tied around the second left maxillary molar to establish the model of periodontitis, and then, mice in group S. salivarius K12 were administered with S. salivarius K12 (2 x 109 CFU) twice daily for 30 d, the others were treated with isopyknic water. Results: Administration with S. salivarius K12 markedly decreased the anaerobic bacteria accumulation on the teeth, and it also considerably alleviated periodontitis-induced alveolar bone resorption and attachment loss. Moreover, S. salivarius K12 administration increased the relative species abundance of Gram-positive bacterium in oral cavity while decreased Gram-negative bacterium, as well as the diversity of the bacterial community. Conclusion: Oral administration of the probiotic S. salivarius K12 may mitigate the alveolar bone resorption and attachment loss of periodontitis by modulating the oral microbiota.
基金supported by MOST Key R&D Program of China(2022YFC2304703)National Natural Science Foundation of China(32270202)Innovative research team of high-level local universities in Shanghai.
文摘The polymorphic microbiome has been defined as one of the“Hallmarks of Cancer”.Extensive studies have now uncovered the role of oral microbiota in cancer development and progression.Bacteria,fungi,archaea,and viruses in the oral cavity interact dynamically with the oral microenvironment to maintain the oral micro-ecological homeostasis.This complex interaction is influenced by many factors,such as maternal transmission,personal factors and environmental factors.Dysbiosis of oral microbiota can disturbed this host-microbiota interaction,leading to systemic diseases.Numerous studies have shown the potential associations between oral microbiota and a variety of cancers.However,the underlying mechanisms and therapeutic insights are still poorly understood.In this review,we mainly focus on the following aspects:(1)the factors affect oral microbiota composition and function;(2)the interaction between microenvironment and oral microbiota;(3)the role of multi-kingdom oral microbiota in human health;(4)the potential underlying mechanisms and therapeutic benefits of oral microbiota against cancer.Finally,we aim to describe the impact of oral microbiota on cancer progression and provide novel therapeutic insights into cancer prevention and treatment by targeting oral microbiota.
基金financially supported by the National Natural Science Foundation of China(Nos.U2006219,51871050 and51901039)the Natural Science Foundation of Liaoning Province(No.20180510041)+1 种基金the Liaoning Revitalization Talents Program(No.XLYC1907158)the Fundamental Research Funds for the Central Universities of the Ministry of Education of China(Nos.N180205021,N180203019,and N2002019)。
文摘In this work,microbiologically influenced corrosion(MIC)of 316 L stainless steel(SS)caused by oral microbiota was investigated with HOMINGS 16 S rRNA gene sequencing technology,and electrochemical and surface analysis techniques.The results showed that oral microbiota from different subjects developed multi-species biofilms with significant differences in structure and composition of bacteria strains on the316 L SS coupons.In the presence of oral microbiota,more severe pitting corrosion and faster dissolution of metallic ions including Ni and Cr were observed.The biofilm considerably decreased the pitting potential of 316 L SS from 1268.0±29.1 mV vs.SCE(abiotic control)to less than 500 mV vs.SCE.The corrosion current density in the presence of oral microbiota from subject 1(115.3±83.3 nA cm^(-2))and subject 2(184.4±162.0 nA cm^(-2))was at least 4 times more than that in the abiotic medium(28.0±2.3 nA cm^(-2)).The electroactive microorganisms with the potential to facilitate corrosion via extracellular electron transfer found in oral microbiota may be mainly responsible for the accelerated corrosion.
文摘Frailty is a critical intermediate status of the aging process with a multidimensional and multisystem nature and at higher risk for adverse health-related outcomes,including falls,disability,hospitalizations,institutionalization,mortality,dementia,and Alzheimer’s disease.Among different frailty phenotypes,oral frailty has been recently suggested as a novel construct defined as a decrease in oral function with a coexisting decline in cognitive and physical functions.We briefly reviewed existing evidence on operational definitions of oral frailty,assessment and screening tools,and possible relationships among oral frailty,oral microbiota,and Alzheimer’s disease neurodegeneration.Several underlying mechanism may explain the oral health-frailty links including undernutrition,sarcopenia linked to both poor nutrition and frailty,psychosocial factors,and the chronic inflammation typical of oral disease.Oral microbiota may influence Alzheimer’s disease risk through circulatory or neural access to the brain and the interplay with periodontal disease,often causing tooth loss also linked to an increased Alzheimer’s disease risk.On this bases,COR388,a bacterial protease inhibitor targeting Porphyromonas gingivalis implicated in periodontal disease,is now being tested in a double-blind,placebocontrolled Phase II/III study in mild-to-moderate Alzheimer’s disease.Therefore,oral status may be an important contributor to general health,including Alzheimer’s disease and latelife cognitive disorders,suggesting the central role of preventive strategies targeting the novel oral frailty phenotype and including maintenance and improvement of oral function and nutritional status to reduce the burden of both oral dysfunction and frailty.
基金supported by a grant from the National Natural Science Foundation(No.81070826/30872886) of Chinapartly sponsored by Shanghai Rising-Star Program(No.12QH1401400)funded by the Shanghai Jiao Tong University(Grant No.YG2011MS67)
文摘The objective of this study was to investigate the compositional profiles and microbial shifts of oral microbiota during head-and-neck radiotherapy.Bioinformatic analysis based on 16S rRNA gene pyrosequencing was performed to assess the diversity and variation of oral microbiota of irradiated patients.Eight patients with head and neck cancers were involved in this study.For each patient, supragingival plaque samples were collected at seven time points before and during radiotherapy.A total of 147 232 qualified sequences were obtained through pyrosequencing and bioinformatic analysis,representing 3 460 species level operational taxonomic units(OTUs) and 140 genus level taxa.Temporal variations were observed across different time points and supported by cluster analysis based on weighted UniFrac metrics.Moreover,the low evenness of oral microbial communities in relative abundance was revealed by Lorenz curves.This study contributed to a better understanding of the detailed characterization of oral bacterial diversity of irradiated patients.
基金Expert Funding of National Natural Science Foundation of China,No.817731741·3·5 project for disciplines of excellence-Clinical Research Incubation and Innovation Project,West China Hospital,Sichuan University,No.ZYJC18044+1 种基金Clinical Research Incubation and Innovation Project of West China Hospital,No.2019HXFH009Science and technology project of Sichuan Province,No.2020YFS0264.
文摘BACKGROUND Microbiota profiles differ between patients with pancreatic cancer and healthy people,and understanding these differences may help in early detection of pancreatic cancer.Saliva sampling is an easy and cost-effective way to determine microbiota profiles compared to fecal and tissue sample collection.AIM To investigate the saliva microbiome distribution in patients with pancreatic adenocarcinoma(PDAC)and the role of oral microbiota profiles in detection and risk prediction of pancreatic cancer.METHODS We conducted a prospective study of patients with pancreatic cancer(n=41)and healthy individuals(n=69).Bacterial taxa were identified by 16S ribosomal ribonucleic acid gene sequencing,and a linear discriminant analysis effect size algorithm was used to identify differences in taxa.Operational taxonomic unit values of all selected taxa were converted into a normalized Z-score,and logistic regressions were used to calculate risk prediction of pancreatic cancer.RESULTS Compared with the healthy control group,carriage of Streptococcus and Leptotrichina(z-score)was associated with a higher risk of PDAC[odds ratio(OR)=5.344,95%confidence interval(CI):1.282-22.282,P=0.021 and OR=6.886,95%CI:1.423-33.337,P=0.016,respectively].Veillonella and Neisseria(z-score)were considered a protective microbe that decreased the risk of PDAC(OR=0.187,95%CI:0.055-0.631,P=0.007 and OR=0.309,95%CI:0.100-0.952,P=0.041,respectively).Among the patients with PDAC,patients reporting bloating have a higher abundance of Porphyromonas(P=0.039),Fusobacterium(P=0.024),and Alloprevotella(P=0.041);while patients reporting jaundice had a higher amount of Prevotella(P=0.008);patients reporting dark brown urine had a higher amount of Veillonella(P=0.035).Patients reporting diarrhea had a lower amount of Neisseria and Campylobacter(P=0.024 and P=0.034),and patients reporting vomiting had decreased Alloprevotella(P=0.036).CONCLUSION Saliva microbiome was able to distinguish patients with pancreatic cancer and healthy individuals.Leptotrichia may be specific for patients living in Sichuan Province,southwest China.Symptomatic patients had different bacteria profiles than asymptomatic patients.Combined symptom and microbiome evaluation may help in the early detection of pancreatic cancer.
