-
Cancers May 2023Oesophagogastric cancer is the fifth most common cancer worldwide, with poor survival outcomes. The role of bacteria in the pathogenesis of oesophagogastric cancer... (Review)
Review
OBJECTIVE
Oesophagogastric cancer is the fifth most common cancer worldwide, with poor survival outcomes. The role of bacteria in the pathogenesis of oesophagogastric cancer remains poorly understood.
DESIGN
A systematic search identified studies assessing the oesophagogastric cancer microbiome. The primary outcome was to identify bacterial enrichment specific to oesophagogastric cancer. Secondary outcomes included appraisal of the methodology, diagnostic performance of cancer bacteria and the relationship between oral and tissue microbiome.
RESULTS
A total of 9295 articles were identified, and 87 studies were selected for analysis. Five genera were enriched in gastric cancer: , , , and . No clear trends were observed in oesophageal adenocarcinoma. , and were abundant in oesophageal squamous cell carcinoma. Functional analysis supports the role of immune cells, localised inflammation and cancer-specific pathways mediating carcinogenesis. STORMS reporting assessment identified experimental deficiencies, considering batch effects and sources of contamination prevalent in low-biomass samples.
CONCLUSIONS
Functional analysis of cancer pathways can infer tumorigenesis within the cancer-microbe-immune axis. There is evidence that study design, experimental protocols and analytical techniques could be improved to achieve more accurate and representative results. Whole-genome sequencing is recommended to identify key metabolic and functional capabilities of candidate bacteria biomarkers.
PubMed: 37345006
DOI: 10.3390/cancers15102668 -
Journal of Neurogastroenterology and... Apr 2020Studies that investigated esophageal microbiomes are limited when compared to those on intestinal microbiomes. Nevertheless, several studies have investigated the... (Review)
Review
Studies that investigated esophageal microbiomes are limited when compared to those on intestinal microbiomes. Nevertheless, several studies have investigated the relationship between esophageal microbiomes and various esophageal diseases, owing to the advancement of next-generation sequencing techniques. is the most common bacterial taxon in a normal esophagus. Additionally, , , , and are also found. However, gram-negative bacteria, including , are more abundant in a diseased esophagus, such as in gastroesophageal reflux disease and Barrett's esophagus. This systematic review aims to summarize current evidences on esophageal microbiomes in various esophageal diseases.
PubMed: 32235026
DOI: 10.5056/jnm19240 -
Cureus Feb 2023Heart failure (HF) contributes to the cardiovascular health burden worldwide. Patients with heart failure have been recently studied to possess unique changes in the gut... (Review)
Review
Heart failure (HF) contributes to the cardiovascular health burden worldwide. Patients with heart failure have been recently studied to possess unique changes in the gut microbiome that affect immune homeostasis and metabolism. In this systematic review of the literature, we aim to identify the impact of gut dysbiosis on heart failure. We used Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines to conduct our systematic review. We searched the literature on databases such as PubMed, PubMed Central (PMC), Medline, and ScienceDirect. Ten articles were included for review. There were significant differences in the gut microbiome composition in heart failure. Relative abundance of and relative depletion of , and The composition varied according to age, heart failure stage, and decompensation level. The composition remained unaltered with ejection fraction. There was an increased expression of genes responsible for the metabolism of amino acids, carbohydrates, choline trimethylamine-lyase (TMA-lyase), lipopolysaccharide (LPS) biosynthesis, tryptophan, and lipid metabolism. The resultant changes affected the levels of metabolites, such as trimethylamine N-oxide (TMAO), indoxyl sulfate (IS), and LPS, and inflammatory markers in the feces and plasma, which contributed to heart failure. These biomarkers of heart failure could serve as targets for the prevention and treatment of heart failure. Patients with heart failure harbor a unique constellation of gut microbiota that affect the pathogenesis of heart failure. Further studies are needed to understand the causal relationship between dysbiosis and heart failure.
PubMed: 36938237
DOI: 10.7759/cureus.34902 -
BMC Cancer Feb 2024Increasing evidence indicates that gut microbiota are closely related to prostate cancer. This study aims to assess the gut microbiota composition in patients with... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Increasing evidence indicates that gut microbiota are closely related to prostate cancer. This study aims to assess the gut microbiota composition in patients with prostate cancer compared to healthy participants, thereby advancing understanding of gut microbiota's role in prostate cancer.
METHODS
A systematic search was conducted across PubMed, Web of Science, and Embase databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The methodological quality of included studies was evaluated using the Newcastle-Ottawa Scale (NOS), and pertinent data were analyzed. The kappa score assessed interrater agreement.
RESULTS
This study encompassed seven research papers, involving 250 prostate cancer patients and 192 controls. The kappa was 0.93. Meta-analysis results showed that alpha-diversity of gut microbiota in prostate cancer patients was significantly lower than in the control group. In terms of gut microbiota abundance, the ratio of Proteobacteria, Bacteroidia, Clostridia, Bacteroidales, Clostridiales, Prevotellaceae, Lachnospiraceae, Prevotella, Escherichia-Shigella, Faecalibacterium, and Bacteroides was higher in prostate cancer patients. Conversely, the abundance ratio of Actinobacteria, Bacteroidetes, Firmicutes, Selenomonadales, Veillonella, and Megasphaera was higher in the control group.
CONCLUSION
Our study reveals differences in alpha-diversity and abundance of gut microbiota between patients with prostate cancer and controls, indicating gut microbiota dysbiosis in those with prostate cancer. However, given the limited quality and quantity of selected studies, further research is necessary to validate these findings.
Topics: Male; Humans; Gastrointestinal Microbiome; Bacteria; Dysbiosis; Prostatic Neoplasms
PubMed: 38402385
DOI: 10.1186/s12885-024-12018-x -
Frontiers in Big Data 2022Despite decades of research, systemic autoimmune diseases (SADs) continue to be a major global health concern and the etiology of these diseases is still not clear. To...
INTRODUCTION
Despite decades of research, systemic autoimmune diseases (SADs) continue to be a major global health concern and the etiology of these diseases is still not clear. To date, with the development of high-throughput techniques, increasing evidence indicated a key role of oral microbiome in the pathogenesis of SADs, and the alterations of oral microbiome may contribute to the disease emergence or evolution. This review is to present the latest knowledge on the relationship between the oral microbiome and SADs, focusing on the multiomics data generated from a large set of samples.
METHODOLOGY
By searching the PubMed and Embase databases, studies that investigated the oral microbiome of SADs, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren's syndrome (SS), were systematically reviewed according to the PRISMA guidelines.
RESULTS
One thousand and thirty-eight studies were found, and 25 studies were included: three referred to SLE, 12 referred to RA, nine referred to SS, and one to both SLE and SS. The 16S rRNA sequencing was the most frequent technique used. HOMD was the most common database aligned to and QIIME was the most popular pipeline for downstream analysis. Alterations in bacterial composition and population have been found in the oral samples of patients with SAD compared with the healthy controls. Results regarding candidate pathogens were not always in accordance, but and were found significantly increased in three SADs, and was significantly decreased in the SADs compared with controls.
CONCLUSION
A large amount of sequencing data was collected from patients with SAD and controls in this systematic review. Oral microbial dysbiosis had been identified in these SADs, although the dysbiosis features were different among studies. There was a lack of standardized study methodology for each study from the inclusion criteria, sample type, sequencing platform, and referred database to downstream analysis pipeline and cutoff. Besides the genomics, transcriptomics, proteomics, and metabolomics technology should be used to investigate the oral microbiome of patients with SADs and also the at-risk individuals of disease development, which may provide us with a better understanding of the etiology of SADs and promote the development of the novel therapies.
PubMed: 35844967
DOI: 10.3389/fdata.2022.927520 -
Medicina (Kaunas, Lithuania) Jul 2019: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired communication, social interaction disorder, and repetitive behavior.... (Meta-Analysis)
Meta-Analysis
: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired communication, social interaction disorder, and repetitive behavior. Dysbiotic gut microbiota (GM) could be a contributing factor to the appearance of ASD, as gastrointestinal (GI) symptoms are comorbidities frequently reported in ASD. As there is a lack of reviews about the role played by GM in the GI symptoms of ASD, this work aimed to carry out a systematic review of current studies comparing the GM of children with ASD and GI symptoms with those of healthy controls in the last six years. The systematic review was performed following the PRISMA guidelines. The databases chosen were Web of Science, Scopus, PubMed, and PsycINFO, and the keywords were (gut* OR intestine* OR bowel* OR gastrointestinal*) AND (microbiota* OR microflora* OR bacteria* OR microbiome* OR flora* OR bacterial* OR bacteria* OR microorganism* OR feces* OR stool*) AND (autistic* OR autism* OR ASD*). : A total of 16 articles were included. Ten articles performed correlations analysis between GI symptoms and ASD. Among those 10 articles, 7 found differences between the GI symptoms present in children with ASD and healthy controls. The most common GI symptom was constipation. Among the seven articles that found differences, three performed correlations analysis between GI symptoms and gut microbe abundance. , , , and showed higher and lower abundance, respectively, in children with ASD and GI symptoms in more than one article. , , , , , , and / ratios showed abundance discrepancies. : It is still too early to draw a conclusion about the gut microbes involved in GI symptoms of ASD. Future research should consider the relationship between ASD behavior, GM, and GI symptoms in a multidisciplinary way and homogenize sample characteristics.
Topics: Autism Spectrum Disorder; Gastrointestinal Microbiome; Gastrointestinal Tract; Humans; Syndrome
PubMed: 31357482
DOI: 10.3390/medicina55080408 -
Frontiers in Oral Health 2024The study aimed to evaluate the impact of tobacco use on the composition and functions of the oral microbiome in healthy adult humans. (Review)
Review
OBJECTIVE
The study aimed to evaluate the impact of tobacco use on the composition and functions of the oral microbiome in healthy adult humans.
METHODS
We conducted a systematic search on PubMed, Web of Science, and Cinhal databases for literature published until 15 December 2023, to identify studies that have evaluated the oral microbiome with culture-independent next-generation techniques comparing the oral microbiome of tobacco users and non-users. The search followed the PECO format. The outcomes included changes in microbial diversity and abundance of microbial taxa. The quality assessment was performed using the Newcastle-Ottawa Scale (NOS) (PROSPERO ID CRD42022340151).
RESULTS
Out of 2,435 articles screened, 36 articles satisfied the eligibility criteria and were selected for full-text review. Despite differences in design, quality, and population characteristics, most studies reported an increase in bacterial diversity and richness in tobacco users. The most notable bacterial taxa enriched in users were and at the phylum level and , , and at the genus level. At the functional level, more similarities could be noted; and were increased in tobacco users compared to non-users. Most of the studies were of good quality on the NOS scale.
CONCLUSION
Tobacco smoking influences oral microbial community harmony, and it shows a definitive shift towards a proinflammatory milieu. Heterogeneities were detected due to sampling and other methodological differences, emphasizing the need for greater quality research using standardized methods and reporting.
SYSTEMATIC REVIEW REGISTRATION
CRD42022340151.
PubMed: 38445094
DOI: 10.3389/froh.2024.1310334 -
Frontiers in Immunology 2024Increasing evidence indicates the microbial ecology of chronic obstructive pulmonary disease (COPD) is intricately associated with the disease's status and severity, and... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Increasing evidence indicates the microbial ecology of chronic obstructive pulmonary disease (COPD) is intricately associated with the disease's status and severity, and distinct microbial ecological variations exist between COPD and healthy control (HC). This systematic review and meta-analysis aimed to summarize microbial diversity indices and taxa relative abundance of oral, airway, and intestine microbiota of different stages of COPD and HC to make comparisons.
METHODS
A comprehensive systematic literature search was conducted in PubMed, Embase, the Web of Science, and the Cochrane Library databases to identify relevant English articles on the oral, airway, and intestine microbiota in COPD published between 2003 and 8 May 2023. Information on microbial diversity indices and taxa relative abundance of oral, airway, and intestine microbiota was collected for comparison between different stages of COPD and HC.
RESULTS
A total of 20 studies were included in this review, involving a total of 337 HC participants, 511 COPD patients, and 154 AECOPD patients. We observed that no significant differences in alpha diversity between the participant groups, but beta diversity was significantly different in half of the included studies. Compared to HC, , , , and of oral microbiota in SCOPD were reduced at the genus level. Most studies supported that , , and were increased, but , , , , and were decreased at the genus level in the airway microbiota of SCOPD. However, the abundance of , and genera exhibited an increase, whereas and showed a decrease in the airway microbiota of AECOPD compared to HC. And of intestine microbiota in SCOPD was reduced at the genus level.
CONCLUSION
The majority of published research findings supported that COPD exhibited decreased alpha diversity compared to HC. However, our meta-analysis does not confirm it. In order to further investigate the characteristics and mechanisms of microbiome in the oral-airway- intestine axis of COPD patients, larger-scale and more rigorous studies are needed.
SYSTEMATIC REVIEW REGISTRATION
PROSPERO (https://www.crd.york.ac.uk/prospero/), identifier CRD42023418726.
Topics: Pulmonary Disease, Chronic Obstructive; Humans; Gastrointestinal Microbiome; Mouth; Microbiota; Bacteria
PubMed: 38779669
DOI: 10.3389/fimmu.2024.1407439 -
Advances in Nutrition (Bethesda, Md.) Jun 2024Microbiota in early life is closely associated with the health of infants, especially premature ones. Probiotics are important drivers of gut microbiota development in... (Meta-Analysis)
Meta-Analysis Review
Microbiota in early life is closely associated with the health of infants, especially premature ones. Probiotics are important drivers of gut microbiota development in preterm infants; however, there is no consensus regarding the characteristics of specific microbiota in preterm infants receiving probiotics. In this study, we performed a meta-analysis of 5 microbiome data sets (1816 stool samples from 706 preterm infants) to compare the gut microbiota of preterm infants exposed to probiotics with that of preterm infants not exposed to probiotics across populations. Despite study-specific variations, we found consistent differences in gut microbial composition and predicted functional pathways between the control and probiotic groups across different cohorts of preterm infants. The enrichment of Acinetobacter, Bifidobacterium, and Lactobacillus spp and the depletion of the potentially pathogenic bacteria Finegoldia, Veillonella, and Klebsiella spp. were the most consistent changes in the gut microbiota of preterm infants supplemented with probiotics. Probiotics drove microbiome transition into multiple preterm gut community types, and notably, preterm gut community type 3 had the highest α-diversity, with enrichment of Bifidobacterium and Bacteroides spp. At the functional level, the major predicted microbial pathways involved in peptidoglycan biosynthesis consistently increased in preterm infants supplemented with probiotics; in contrast, the crucial pathways associated with heme biosynthesis consistently decreased. Interestingly, Bifidobacterium sp. rather than Lactobacillus sp. gradually became dominant in gut microbiota of preterm infants using mixed probiotics, although both probiotic strains were administered at the same dosage. Taken together, our meta-analysis suggests that probiotics contribute to reshaping the microbial ecosystem of preterm infants at both the taxonomic and functional levels of the bacterial community. More standardized and relevant studies may contribute to better understanding the crosstalk among probiotics, the gut microbiota, and subsequent disease risk, which could help to give timely nutritional feeding guidance to preterm infants. This systematic review and meta-analysis was registered at PROSPERO (https://www.crd.york.ac.uk/PROSPERO/) as CRD42023447901.
Topics: Humans; Gastrointestinal Microbiome; Probiotics; Infant, Premature; Infant, Newborn; Bifidobacterium; Feces; Bacteria; Lactobacillus; Female
PubMed: 38908894
DOI: 10.1016/j.advnut.2024.100233 -
Gut Microbes 2023Growth failure is among the most prevalent and devastating consequences of prematurity. Up to half of all extremely preterm neonates struggle to grow despite modern...
Growth failure is among the most prevalent and devastating consequences of prematurity. Up to half of all extremely preterm neonates struggle to grow despite modern nutrition practices. Although elegant preclinical models suggest causal roles for the gut microbiome, these insights have not yet translated into biomarkers that identify at-risk neonates or therapies that prevent or treat growth failure. This systematic review aims to identify features of the neonatal gut microbiota that are positively or negatively associated with early postnatal growth. We identified 860 articles, of which 14 were eligible for inclusion. No two studies used the same definitions of growth, ages at stool collection, and statistical methods linking microbiota to metadata. In all, 58 different taxa were associated with growth, with little consensus among studies. Two or more studies reported positive associations with Enterobacteriaceae, , , , and , and negative associations with , and . was positively associated with growth in five studies and negatively associated with growth in three studies. To gain insight into how the various definitions of growth could impact results, we performed an exploratory secondary analysis of 245 longitudinally sampled preterm infant stools, linking microbiota composition to multiple clinically relevant definitions of neonatal growth. Within this cohort, every definition of growth was associated with a different combination of microbiota features. Together, these results suggest that the lack of consensus in defining neonatal growth may limit our capacity to detect consistent, meaningful clinical associations that could be leveraged into improved care for preterm neonates.
Topics: Infant; Infant, Newborn; Humans; Infant, Premature; Gastrointestinal Microbiome; Feces; Microbiota; Enterobacteriaceae
PubMed: 36927287
DOI: 10.1080/19490976.2023.2190301