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British Journal of Cancer May 2022Substantial evidence indicates that dysbiosis of the gut microbial community is associated with colorectal neoplasia. This review aims to systematically summarise the...
BACKGROUND
Substantial evidence indicates that dysbiosis of the gut microbial community is associated with colorectal neoplasia. This review aims to systematically summarise the microbial markers associated with colorectal neoplasia and to assess their predictive performance.
METHODS
A comprehensive literature search of MEDLINE and EMBASE databases was performed to identify eligible studies. Observational studies exploring the associations between microbial biomarkers and colorectal neoplasia were included. We also included prediction studies that constructed models using microbial markers to predict CRC and adenomas. Risk of bias for included observational and prediction studies was assessed.
RESULTS
Forty-five studies were included to assess the associations between microbial markers and colorectal neoplasia. Nine faecal microbiotas (i.e., Fusobacterium, Enterococcus, Porphyromonas, Salmonella, Pseudomonas, Peptostreptococcus, Actinomyces, Bifidobacterium and Roseburia), two oral pathogens (i.e., Treponema denticola and Prevotella intermedia) and serum antibody levels response to Streptococcus gallolyticus subspecies gallolyticus were found to be consistently associated with colorectal neoplasia. Thirty studies reported prediction models using microbial markers, and 83.3% of these models had acceptable-to-good discrimination (AUROC > 0.75). The results of predictive performance were promising, but most of the studies were limited to small number of cases (range: 9-485 cases) and lack of independent external validation (76.7%).
CONCLUSIONS
This review provides insight into the evidence supporting the association between different types of microbial species and their predictive value for colorectal neoplasia. Prediction models developed from case-control studies require further external validation in high-quality prospective studies. Further studies should assess the feasibility and impact of incorporating microbial biomarkers in CRC screening programme.
Topics: Adenoma; Biomarkers; Colorectal Neoplasms; Dysbiosis; Humans; Prospective Studies
PubMed: 35292756
DOI: 10.1038/s41416-022-01740-7 -
PloS One 2021To assess the prevalence of unculturable bacteria in periapical abscess, radicular cyst, and periapical granuloma. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To assess the prevalence of unculturable bacteria in periapical abscess, radicular cyst, and periapical granuloma.
METHODS
PubMed, Scopus, Science Direct, and Ovid databases were systematically searched from January 1990 to May 2020. All the included studies were cross-sectional design. The risk of bias was assessed using Joanna Briggs Institute check-list. Heterogeneity was described using meta-regression and mixed-effects model for lesion, country, and sequence technique moderators. Funnel plot and unweighted Egger's regression test were used to estimate the publication bias. Microbiome data on diversity, abundance, and frequency of unculturable bacteria in the periapical lesions were reviewed, analysed, and the principal component analysis (PCA) was performed.
RESULTS
A total of 13 studies out of 14,780, were selected for the final analysis. These studies focused on the prevalence of unculturable bacteria in periapical abscesses and related lesions. Approximately 13% (95% CI: 7-23%) of the cumulative number of bacteria derived from periapical abscesses was unculturable. Country moderator significantly (P = 0.05) affects the diversity summary proportion. While the pooled frequency of unculturable bacteria was 8%; 95% CI: 5, 14%, the estimate of the pooled abundance of unculturable bacteria was 5%; 95% CI: 2, 12% with a significant (P = 0.05) country moderator that affects the abundance summary proportion. Of the 62 unculturable bacteria, 35 were subjected to PCA and Peptostreptococcus sp. oral clone CK035 was the most abundant species in periapical abscesses. Hybridization techniques were found to be the most reliable molecular methods in detecting the abundance and frequency of unculturable bacteria.
CONCLUSION
The significant prevalence of unculturable bacteria in the periapical abscess, suggests that they are likely to play, a yet unknown, critical role in the pathogenesis and progression of the disease. Further research remains to be done to confirm their specific contributions in the virulence and disease progression.
Topics: Bacteria; Bacterial Infections; Humans; Periapical Abscess; Prevalence
PubMed: 34351963
DOI: 10.1371/journal.pone.0255485 -
Nutrients Apr 2021Growing attention has been given to the role of nutrition and alterations of microbial diversity of the gut microbiota in colorectal cancer (CRC) pathogenesis. It has...
BACKGROUND
Growing attention has been given to the role of nutrition and alterations of microbial diversity of the gut microbiota in colorectal cancer (CRC) pathogenesis. It has been suggested that probiotics and synbiotics modulate enteric microbiota and therefore may be used as an intervention to reduce the risk of CRC. The aim of this study was to evaluate the influence of probiotics/synbiotics administration on gut microbiota in patients with CRC.
METHODS
PubMed, Scopus, and Web of Science were searched between December 2020 and January 2021. Randomized controlled trials (RCTs) recruiting adults with CRC, who have taken probiotics/synbiotics for at least 6 days were included. Changes in gut microbiota and selected biochemical and inflammatory parameters (i.e., hsCRP, IL-2, hemoglobin) were retrieved.
RESULTS
The search resulted in 198 original research articles and a final 6 were selected as being eligible, including 457 subjects. The median age of patients was 65.4 years old and they were characterized by the median BMI value: 23.8 kg/m. The literature search revealed that probiotic/synbiotic administration improved enteric microbiota by increasing the abundance of beneficial bacteria such as and , and decreased the abundance of potentially harmful bacteria such as and . Additionally, probiotic/synbiotic intervention improved release of antimicrobials, intestinal permeability, tight junction function in CRC patients.
CONCLUSIONS
The use of probiotics/synbiotics positively modulates enteric microbiota, improves postoperative outcomes, gut barrier function and reduces inflammatory parameters in patients suffering from CRC.
Topics: Bacteria; Colorectal Neoplasms; Gastrointestinal Microbiome; Humans; Probiotics
PubMed: 33915854
DOI: 10.3390/nu13041160 -
Journal of Stomatology, Oral and... Apr 2021Alveolar osteitis (AO) or dry socket after dental extractions is a common postoperative complication characterized by the presence of severe pain associated with an...
Alveolar osteitis (AO) or dry socket after dental extractions is a common postoperative complication characterized by the presence of severe pain associated with an empty socket. Although some authors consider AO to be related to an alteration of the blood clot, the underlying etiology remains unclear, and recent reports suggest that bacteria might play an important role. A systematic review was made, compiling relevant references from PubMed, the Cochrane Library, Scopus and the Web of Science databases to determine which bacteria have been identified in AO sockets after dental extractions. Papers published between 1980-2019, identifying the bacteria present in AO sockets after tooth extractions, were included. Data were displayed in tables, and a descriptive analysis was carried out. After the screening process, four papers were analyzed, comprising a total of 138 samples from 138 patients with AO. The most commonly detected bacteria were Prevotella, Fusobacterium, Parvimonas and Peptostreptococcus. Two studies also showed the microbiota of patients that developed AO after dental extractions to be apparently different from that of patients without postoperative complications. These results indicate that bacteria may play an important role in the pathogenesis of AO, though further studies are needed to confirm these findings.
Topics: Dry Socket; Humans; Microbiota; Molar, Third; Postoperative Complications; Tooth Extraction
PubMed: 32896676
DOI: 10.1016/j.jormas.2020.08.007 -
Cancer Epidemiology, Biomarkers &... Oct 2020The microbiome has been hypothesized to play a role in cancer development. Because of the diversity of published data, an overview of available epidemiologic evidence...
The microbiome has been hypothesized to play a role in cancer development. Because of the diversity of published data, an overview of available epidemiologic evidence linking the microbiome with cancer is now needed. We conducted a systematic review using a tailored search strategy in Medline and EMBASE databases to identify and summarize the current epidemiologic literature on the relationship between the microbiome and different cancer outcomes published until December 2019. We identified 124 eligible articles. The large diversity of parameters used to describe microbial composition made it impossible to harmonize the different studies in a way that would allow meta-analysis, therefore only a qualitative description of results could be performed. Fifty studies reported differences in the gut microbiome between patients with colorectal cancer and various control groups. The most consistent findings were for , and being significantly enriched in fecal and mucosal samples from patients with colorectal cancer. For the oral microbiome, significantly increased and decreased abundance was reported for and , respectively, in patients with oral cancer compared with controls. Overall, although there was a large amount of evidence for some of these alterations, most require validation in high-quality, preferably prospective, epidemiologic studies.
Topics: Gastrointestinal Microbiome; Humans; Neoplasms; Risk
PubMed: 32727720
DOI: 10.1158/1055-9965.EPI-20-0288 -
Journal of the Turkish German... Sep 2020Accumulating evidence indicates the potential correlation between the vaginal microbioma and the acquisition and persistence of human papillomavirus (HPV) infection....
Accumulating evidence indicates the potential correlation between the vaginal microbioma and the acquisition and persistence of human papillomavirus (HPV) infection. This study aims to demonstrate the potential relationship through a systematic review of the current literature. A search was conducted on the following medical databases: PubMed and Scopus. Nineteen studies met the inclusion criteria and were incorporated in the present review. A total of 12.204 patients and their demographic characteristics were studied. Commercially available DNA tests and polymerase chain reaction (PCR) were used for the detection of different HPV subtypes, while the identification of the microbiomes was performed through specific diagnostic methods and PCR assay. The most frequently encountered species were classified based on their protective or detrimental impact on the progression of HPV infection. The beneficial role of some types of is generally supported. On the other hand, high microbial diversity and specific microorganisms such as and were found to be implicated with higher frequency and severity of disease, potentially resulting in pre-cancerous and cancerous cervical lesions.The role of vaginal microbiota appears to play an as yet not fully understood role in the susceptibility to HPV infection and its natural history.
PubMed: 31564082
DOI: 10.4274/jtgga.galenos.2019.2019.0051