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Frontiers in Cellular and Infection... 2022Evidence of gut microbiota involvement in regulating glucose metabolism and type 2 diabetes mellitus (T2DM) progression is accumulating. The understanding of microbial... (Review)
Review
Evidence of gut microbiota involvement in regulating glucose metabolism and type 2 diabetes mellitus (T2DM) progression is accumulating. The understanding of microbial dysbiosis and specific alterations of gut microbiota composition that occur during the early stages of glucose intolerance, unperturbed by anti-diabetic medications, is especially essential. Hence, this systematic review was conducted to summarise the existing evidence related to microbiota composition and diversity in individuals with prediabetes (preDM) and individuals newly diagnosed with T2DM (newDM) in comparison to individuals with normal glucose tolerance (nonDM). A systematic search of the PubMed, MEDLINE and CINAHL databases were conducted from inception to February 2021 supplemented with manual searches of the list of references. The primary keywords of "type 2 diabetes", "prediabetes", "newly-diagnosed" and "gut microbiota" were used. Observational studies that conducted analysis of the gut microbiota of respondents with preDM and newDM were included. The quality of the studies was assessed using the modified Newcastle-Ottawa scale by independent reviewers. A total of 18 studies (5,489 participants) were included. Low gut microbial diversity was generally observed in preDM and newDM when compared to nonDM. Differences in gut microbiota composition between the disease groups and nonDM were inconsistent across the included studies. Four out of the 18 studies found increased abundance of phylum along with decreased abundance of in newDM. At the genus/species levels, decreased abundance of , , , and and increased abundance of , a, and were observed in the disease groups in at least two studies. was also found to positively correlate with fasting plasma glucose (FPG), HbA1c and/or homeostatic assessment of insulin resistance (HOMA-IR) in four studies. This renders a need for further investigations on the species/strain-specific role of endogenously present in glucose regulation mechanism and T2DM disease progression. Differences in dietary intake caused significant variation in specific bacterial abundances. More studies are needed to establish more consistent associations, between clinical biomarkers or dietary intake and specific gut bacterial composition in prediabetes and early T2DM.
Topics: Bacteroidetes; Diabetes Mellitus, Type 2; Gastrointestinal Microbiome; Glucose; Humans; Microbiota; Verrucomicrobia
PubMed: 36046745
DOI: 10.3389/fcimb.2022.943427 -
Microorganisms Aug 2022Our systematic review aimed to evaluate the effect of periodontal interventions on the diversity and composition of periodontal microbiota assessed by high throughput...
Our systematic review aimed to evaluate the effect of periodontal interventions on the diversity and composition of periodontal microbiota assessed by high throughput sequencing (HTS) metagenomics analysis. An electronic search was conducted from database inception to November 2021. All clinical trials that evaluated the effect of periodontal interventions on the gingival microbiota through HTS were selected. The measures of alpha diversity, richness, Shannon diversity index, and the Chao1 index, were used as the primary outcome, whereas relative abundances of bacterial genera were considered as the secondary outcome. Overall, 24 studies were eligible for the systematic review, of which 13 studies were included in the meta-analysis. Periodontal intervention for the test group decreased Shannon diversity, richness, and Chao1 index (alpha diversity), as observed from baseline to post-treatment. The most common genera that increased after periodontal therapy were , , , , and , whilst , , , and decreased after periodontal therapy. Periodontal interventions may decrease the bacterial diversity and richness and alter the composition of oral microbiota in the short term. Periodontal microbiota signatures could potentially be used for the assessment of periodontal disease development, progression, and success of the intervention.
PubMed: 36014000
DOI: 10.3390/microorganisms10081582 -
Clinical and Experimental Dental... Dec 2022Diet is one of the main factors influencing the diversity and interactions of the oral microbiota. The purpose of this study is to determine the impact of sugar intake... (Review)
Review
OBJECTIVES
Diet is one of the main factors influencing the diversity and interactions of the oral microbiota. The purpose of this study is to determine the impact of sugar intake on the microbial diversity and bacteria that predominate under these conditions.
MATERIAL AND METHODS
A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guide, using the PubMed, Scopus, and Science Direct databases and combinations of the words "microbiota," "microbiology," "bacteria," "sugars," "dysbiosis," "caries," "microbiome," "oral microbial," and "oral microbiota profile pattern." The selection criteria included year, language, type of publication, comparison of microbiota during low and high sugar intake, and bacterial identification by molecular sequencing of the 16S subunit of ribosomal RNA.
RESULTS
Out of a total of 374 papers that came up after the initial search, 8 met the criteria for this review. The papers included research on populations comprising children, young adults, and adults, with most of the studies reporting selection criteria for the participants and using validated instruments to determine sugar intake. Apart from one study, all others reported for high sugar intake conditions a significant decrease in microbial diversity of the oral microbiome and the predominance of several bacterial genera or species, including Streptococcus, Scardovia, Veillonella, Rothia, Actinomyces, and Lactobacillus.
CONCLUSIONS
Sugar-rich diets have a significantly unfavorable effect on the diversity and balance of oral microbiota; however, further studies are required to determine the exact role of sugar in microbial interactions.
Topics: Child; Young Adult; Humans; Microbiota; Bacteria; Dental Caries; Dysbiosis; Sugars
PubMed: 35946056
DOI: 10.1002/cre2.640 -
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 -
Frontiers in Oral Health 2021In light of recent technological advances in Next-generation sequencing (NGS) and the accumulation of large, publicly available oral microbiome datasets, the need for...
In light of recent technological advances in Next-generation sequencing (NGS) and the accumulation of large, publicly available oral microbiome datasets, the need for meta-analysing data on caries microbiome is becoming feasible and essential. A consensus on the identification of enriched organisms in cariogenic dysbiotic biofilms would be reached. For example, members of the genus have been detected in caries biofilms, and may have an underestimated contribution to the dysbiotic process. Hence, we aimed to determine the abundance of species in dental caries in studies using NGS data. Analysis was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (registered at PROSPERO: CRD42020204150). Studies investigating microbial composition in saliva, dental biofilm, or carious dentin were included. Six databases and grey literature were searched. Two independent reviewers selected the papers and assessed the methodological quality. Searches retrieved 1,323 titles, from which 38 studies were included in a qualitative synthesis, comprising a total of 1,374 caries and 745 caries-free individuals. Most studies analysed 16S rRNA amplicons, and only 5 studies used shotgun metagenomics and metatranscriptomics. A geographical bias was observed. The methodological quality was downrated in 81.5% of the studies due to the lack of criteria for defining cases and standard criteria used for measurement of the condition in a reliable way. Six studies on early childhood caries (ECC) were meta-analysed, confirming a significant enrichment of spp. in caries-associated biofilms (but not saliva) when compared to caries-free controls [mean difference: 2.22 (0.54-3.90); = 0.01]. . is more abundant in individuals suffering with ECC when compared to caries-free controls (very low evidence certainty), and should be considered for further studies to observe their metabolism in dental caries. There is an urgent need for a consensus in methodologies used to allow for more rigorous comparison between NGS studies, particularly including clinical data and details of caries diagnosis, as they are currently scarce. Inconsistent reporting on the NGS data affected the cross-study comparison and the biological connexions of the relative abundances on caries microbiome.
PubMed: 35048071
DOI: 10.3389/froh.2021.770917 -
Seminars in Cancer Biology Nov 2022The higher incidence of bladder cancer in men has long been attributed to environmental factors, including smoking. The fact that the sex ratio of bladder cancer remains... (Review)
Review
The higher incidence of bladder cancer in men has long been attributed to environmental factors, including smoking. The fact that the sex ratio of bladder cancer remains consistently weighted toward men despite the remarkable increase in the prevalence of smoking among women suggests that other risk factors influence the incidence rates of bladder cancer. These factors may include the urinary microbiota. In this study, we provide a review of recent literature regarding the association between bladder cancer and changes in the urinary microbiota, with a focus on the potential role of uropathogens in the microbiota and sex in bladder cancer. Four databases were systematically searched up to 31 March 2021 to identify human case-controlled studies that evaluated the relationship between urinary microbiota and bladder cancer. We combined bacterial taxa that were significantly higher or lower in the bladder cancer group in each study in the urine (voided and catheterized) and tissue samples. Findings from sixteen eligible studies were analyzed. The total sample size of the included studies was 708 participants, including 449 (63.4 %) bladder cancer patients and 259 (36.6 %) participants in the control group. When considering only the taxa that have been reported in at least two different studies, we observed that with regards to neoplastic tissues, no increased taxa were reported, while Lactobacillus (2/5 of the studies on tissue samples) was increased in nonneoplastic-tissue compared to neoplastic-tissues at the genus level. In catheterized urine, Veillonella (2/3 of the studies on catheterized urine) was increased in bladder cancer patients compared to the control groups at the genus level. In voided urine, Acinetobacter, Actinomyces, Aeromonas, Anaerococcus, Pseudomonas, and Tepidomonas were increased in the bladder cancer patients, while Lactobacillus, Roseomonas, Veillonella were increased in the control groups. Regarding gender, the genus Actinotignum was increased in female participants while Streptococcus was increased in male participants at the genus level. Regarding potential uropathogens in the urinary microbiota, Escherichia-Shigella provided conflicting results, with both showing higher and lower levels in the bladder cancer groups. However, the family Enterobacteriaceae was lower in the bladder cancer groups than in the control groups. In conclusion, there is no consensus on what taxa of the urinary microbiota are associated with bladder cancer according to the sample type. Findings on the potential role of uropathogens in the urinary microbiota in bladder cancer remain inconsistent. Due to the limited number of studies, further studies on urinary microbiota and bladder cancer are needed to address this issue. Given that all publications concerning the urinary microbiota and bladder cancer have been performed using 16S rRNA gene sequencing, we propose that polyphasic approaches, including culture-dependent techniques, may allow for a more comprehensive investigation of the urinary microbiota associated with bladder cancer.
Topics: Humans; Female; Male; Urinary Bladder Neoplasms; RNA, Ribosomal, 16S; Urinary Bladder; Microbiota; Bacteria
PubMed: 34979272
DOI: 10.1016/j.semcancer.2021.12.010 -
Zhonghua Xin Xue Guan Bing Za Zhi Oct 2021To analyze the changes on gut microbiota and metabolic products in patients with chronic heart failure. By searching the Pubmed, EMBASE, Cochrane Library, and CNKI,...
To analyze the changes on gut microbiota and metabolic products in patients with chronic heart failure. By searching the Pubmed, EMBASE, Cochrane Library, and CNKI, Wanfang, and CMB databases from the day of built up to December 2019, we screened related literature exploring the intestinal flora of chronic heart failure patients, and systematic review was performed to study changes in intestinal flora composition, function, and metabolites among chronic heart failure patients. A total of 10 articles were included to study the gut microbiota of patients with chronic heart failure in this analysis. The systematic review showed significant changes in β-diversity in patients with heart failure. The abundance of faecalibacterium, blautia, bacteroides, prevotella and anaerostipes was decreased, while the abundance of streptococcus, escherichia/shigella, veillonella, and enterobacte was increased. The increased microbial gene function in patients with heart failure included tryptophan metabolism, lipid metabolism, LPS synthesis,and so on, especially, bacterial genes related to trimethylamine oxide production increased significantly, while genes related to key enzymes producing the beneficial metabolite butyrate decreased significantly, and harmful metabolite trimethylamine oxide levels increased in chronic heart failure patients. There are significant changes in the structure, function and metabolites of intestinal flora in patients with chronic heart failure.
Topics: Chronic Disease; Gastrointestinal Microbiome; Heart Failure; Humans
PubMed: 34674439
DOI: 10.3760/cma.j.cn112148-20210831-00754 -
Advances in Rheumatology (London,... Jul 2021Systemic Lupus Erythematosus (SLE) is an autoimmune disease, characterized by being multi-systemic and, therefore, reaching various organs and affecting mainly young...
BACKGROUND
Systemic Lupus Erythematosus (SLE) is an autoimmune disease, characterized by being multi-systemic and, therefore, reaching various organs and affecting mainly young women. Its pathogenesis comprehends many factors, including the interaction between microbiota and immune system. This systematic review assessed the relationship between intestinal microbiota and SLE in activity, highlighting microbiota representative patterns regarding quantity and diversity.
METHODS
This study considered researches carried out in patients with SLE, with no restriction of age or gender, which fulfilled the classification criteria of either Systemic Lupus International Collaborating Clinic (SLICC), American College of Rheumatology (ACR) or European League Against Rheumatism (EULAR) and used the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) to classify disease in activity or remission were included. The search was carried out from October, 2020 to January, 2021 using the following databases: Medline via Pubmed, Scopus, and Embase. Five papers were included with a total of 288 participants with SLE.
RESULTS
Regarding microbiota in patients with SLE in activity, there was significant increase in the following genera: Lactobacillus, Streptococcus, Megasphaera, Fusobacterium, Veillonella, Oribacterium, Odoribacter, Blautia, and Campylobacter. On the other hand, decrease in Faecalibacterium and Roseburia genera as well as Ruminococcus gnavus species was observed in remission cases, showing differences between the microbiota profile in SLE in activity and in remission.
CONCLUSIONS
Results suggest that dysbiosis may be involved in the disease activity process.
TRIAL REGISTRATION
CRD42021229322 .
Topics: Gastrointestinal Microbiome; Humans; Lupus Erythematosus, Systemic
PubMed: 34215348
DOI: 10.1186/s42358-021-00201-8 -
Archives of Oral Biology Sep 2021This study aimed to investigate that these bacteria counts in the oral cavity were modulated by the recurrent aphthous stomatitis (RAS) status according to age and... (Meta-Analysis)
Meta-Analysis Review
Quantitative changes of Veillonella, Streptococcus, and Neisseria in the oral cavity of patients with recurrent aphthous stomatitis: A systematic review and meta-analysis.
OBJECTIVE
This study aimed to investigate that these bacteria counts in the oral cavity were modulated by the recurrent aphthous stomatitis (RAS) status according to age and ethnicity with a systematic review and meta-analysis.
DESIGN
The relevant case-control studies were searched in the literature database in English, Korean, and Chinese until June 2020 using keywords, and the literature was screened and collated for Review Manager analysis. Sensitivity analysis and quality check of the included literature were conducted.
RESULTS
From the selection process, oral bacteria counts were measured by polymerase chain reaction (PCR) in 8 studies and next-generation sequencing in 4 studies. Healthy control, ulcerative phases of RAS (UC-RAS), non-ulcerative phases of RAS (Non-UC-RAS) groups included 442, 473, and 386 participants in a total of 12 studies. For PCR detection, mean differences (95 % confidence intervals) of Veillonella and Streptococcus counts between the healthy-control and RAS groups were -1.91 (-2.41 ∼ -1.41) and -1.34 (-1.85 ∼ -0.83)(P < 0.0001). The bacteria count results by "Next-generation" sequencing (NGS) and PCR methods were similar. Significantly lower Veillonella and Streptococcus counts were observed in the UC-RAS group than in the non-UC-RAS group (P < 0.0001). Veillonella and Streptococcus count differences between RAS and controls aged ≥30 years were greater than those aged <30 years. At the species level, the prevalence of RAS had a negative relation with Veillonella dispar count.
CONCLUSIONS
Counts of Veillonella and Streptococcus are strongly correlated with the recovery and progression of RAS, especially in middle-aged patients. Adjustment of oral microbiota should be considered in the treatment of RAS.
Topics: Humans; Middle Aged; Neisseria; Stomatitis, Aphthous; Streptococcus; Veillonella
PubMed: 34167010
DOI: 10.1016/j.archoralbio.2021.105198 -
Frontiers in Psychiatry 2020Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to...
Cumulative evidence shows a linkage between gut microbiota pattern and depression through the brain-gut microbiome axis. The aim of this systematic review was to identify the alterations of the gut microbiota patterns in people with depression compared to healthy controls. A comprehensive literature search of human studies, published between January 2000 and June 2019, was reviewed. The key words included gastrointestinal microbiome, gut microbiome, microbiota, depression, depressive symptoms, and depressive disorder. The systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Nine articles met the eligibility criteria. Disparities in α-diversity and β-diversity of the microbiota existed in people with depression compared to healthy controls. At the phylum level, there were inconsistencies in the abundance of , , . However, high abundance in and phyla were observed in people with depression. On the family level, high abundance of , , , , , , , , , , , , , low abundance of , , , , , , and were observed in people with depression. On the genus level, high abundance of , , , , , , , , , , , , , , , , , , , , , , , and low abundance of , , , , , , , and were found in people with depression. Alteration of gut microbiome patterns was evident in people with depression. Further evidence is warranted to allow for the translation of microbiome findings toward innovative clinical strategies that may improve treatment outcomes in people with depression.
PubMed: 32587537
DOI: 10.3389/fpsyt.2020.00541