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Gut microbiota in patients with Alzheimer's disease spectrum: a systematic review and meta-analysis.Aging Jan 2022Gut dysbiosis has been proposed as one of pathologies in patients with Alzheimer's disease (AD) spectrum. Despite such enthusiasm, the relevant results remain... (Meta-Analysis)
Meta-Analysis
CONTEXT
Gut dysbiosis has been proposed as one of pathologies in patients with Alzheimer's disease (AD) spectrum. Despite such enthusiasm, the relevant results remain substantially controversial.
OBJECTIVE
A systematic review and meta-analysis were performed to investigate the differences of gut microbiota (GM) between patients with AD spectrum (including mild cognitive impairment [MCI] and AD) and healthy controls (HC).
DATA SOURCES
PubMed, MEDLINE, Scopus, and Cochrane Library from January 2000 to August 2021. Eligibility criteria for study selection: Observational trials and pre-intervention data of intervention trials that investigated the abundance of GM in patients with AD spectrum and HC.
DATA EXTRACTION AND SYNTHESIS
Two reviewers independently identified articles, extracted data, and evaluated the risk of bias. The effect sizes were performed by a random-effect, inverse-variance weighted model. The effects of different countries and of clinical stages on GM abundance were also examined.
RESULTS
11 studies consisting of 378 HC and 427 patients with AD spectrum were included in the meta-analysis. Patients with AD, but not MCI, showed significantly reduced GM diversity as compared to HC. We also found more abundance of , and , but less abundance of , , and in patients with AD spectrum as compared with HC. The profiles of abundance of and in HC and AD spectrum were differentially affected by countries. Finally, when considering clinical stage as a moderator, the comparisons of abundance in and showed large effect sizes, with gradient changes from MCI to AD stage.
LIMITATIONS
The inclusion of studies originating only from China and the U.S. was a possible limitation.
CONCLUSIONS
Patients with AD spectrum demonstrated altered GM abundance, which was differentially mediated by countries and clinical stages.
Topics: Aged; Alzheimer Disease; Bacteria; Female; Gastrointestinal Microbiome; Humans; Male; Middle Aged
PubMed: 35027502
DOI: 10.18632/aging.203826 -
Gastroenterology Aug 2020
Topics: Bacteria; Consensus; Dysbiosis; Evidence-Based Medicine; Gastroenterology; Gastrointestinal Diseases; Gastrointestinal Microbiome; Humans; Intestines; Probiotics; Treatment Outcome
PubMed: 32531291
DOI: 10.1053/j.gastro.2020.05.059 -
Nutrients Jul 2021The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut...
The human gut microbiota are the microorganisms (generally bacteria and archaea) that live in the digestive tracts of humans. Due to their numerous functions, the gut microbiota can be considered a virtual organ of the body, playing a pivotal role in health maintenance. Dietary habits contribute to gut microbiota composition, and evidence from observational and intervention studies suggest that vegan diets may promote health, potentially through affecting the diverse ecosystem of beneficial bacteria in the gut. A systematic literature search was conducted on PubMed and Scopus to identify studies investigating the microbiota composition in vegans. Vegans are defined as people excluding food products that are derived from animals from their diet. Nine observational studies were identified. The main outcome of the systematic review was an increase in Bacteroidetes on the phylum level and a higher abundance of on the genus level. In conclusion, the present systematic literature review highlighted some benefits of a vegan diet but also demonstrated the complexity of evaluating results from gut microbiota research. The available evidence only consisted of cross-sectional studies, therefore suggesting the need for well-designed randomised controlled trials. Furthermore, the quality assessment of the studies included in the review suggested a lack of standardised and validated methods for participant selection as well as for faecal sampling and faecal analysis.
Topics: Adult; Bacteria; Diet, Healthy; Diet, Vegan; Dysbiosis; Feces; Female; Gastrointestinal Microbiome; Humans; Intestines; Male; Middle Aged; Nutritive Value
PubMed: 34371912
DOI: 10.3390/nu13072402 -
Anaesthesia, Critical Care & Pain... Dec 2023Accuracy and timing of antibiotic therapy remain a challenge for lower respiratory tract infections. New molecular techniques using Multiplex Polymerase Chain Reaction,... (Meta-Analysis)
Meta-Analysis Review
Performance evaluation of a PCR panel (FilmArray® Pneumonia Plus) for detection of respiratory bacterial pathogens in respiratory specimens: A systematic review and meta-analysis.
BACKGROUND
Accuracy and timing of antibiotic therapy remain a challenge for lower respiratory tract infections. New molecular techniques using Multiplex Polymerase Chain Reaction, including the FilmArray® Pneumonia Plus Panel [FAPP], have been developed to address this. The aim of this study is to evaluate the FAPP diagnostic performance for the detection of the 15 typical bacteria of the panel from respiratory samples in a meta-analysis from a systematic review.
METHODS
We searched PubMed and EMBASE from January 1, 2010, to December 31, 2022, and selected any study on the FAPP diagnostic performance on respiratory samples compared to the reference standard, bacterial culture. The main outcome was the overall diagnostic accuracy with sensitivity and specificity. We calculated the log Diagnostic Odds Ratio and analyzed performance for separate bacteria, antimicrobial resistance genes, and according to the sample type. We also reported the FAPP turnaround time and the out-of-panel bacteria number and species. This study is registered with PROSPERO (CRD42021226280).
RESULTS
From 10 317 records, we identified 30 studies including 8 968 samples. Twenty-one were related to intensive care. The overall sensitivity and specificity were 94% [95% Confidence Interval (CI) 91-95] and 98% [95%CI 97-98], respectively. The log Diagnostic Odds Ratio was 6.35 [95%CI 6.05-6.65]. 9.3% [95%CI 9.2-9.5] of bacteria detected in culture were not included in the FAPP panel.
CONCLUSION
This systematic review reporting the FAPP evaluation revealed a high accuracy. This test may represent an adjunct tool for pulmonary bacterial infection diagnostic and antimicrobial stewardship. Further evidence is needed to assess the impact on clinical outcome.
Topics: Humans; Bacteria; Pneumonia; Respiratory Tract Infections; Bacterial Infections; Multiplex Polymerase Chain Reaction
PubMed: 37709201
DOI: 10.1016/j.accpm.2023.101300 -
Gastroenterology Mar 2020Altering the intestinal microbiota has been proposed as a treatment for inflammatory bowel diseases (IBDs), but there are no established associations between specific...
BACKGROUND & AIMS
Altering the intestinal microbiota has been proposed as a treatment for inflammatory bowel diseases (IBDs), but there are no established associations between specific microbes and IBD. We performed a systematic review to identify frequent associations.
METHODS
We searched the MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases, through April 2, 2018 for studies that compared intestinal microbiota (from fecal or colonic or ileal tissue samples) among patients (adult or pediatric) with IBD vs healthy individuals (controls). The primary outcome was difference in specific taxa in fecal or intestinal tissue samples from patients with IBD vs controls. We used the Newcastle-Ottawa scale to assess the quality of studies included in the review.
RESULTS
We identified 2631 citations; 48 studies from 45 articles were included in the analysis. Most studies evaluated adults with Crohn's disease or ulcerative colitis. All 3 studies of Christensenellaceae and Coriobacteriaceae and 6 of 11 studies of Faecalibacterium prausnitzii reported a decreased amount of those organisms compared with controls, whereas 2 studies each of Actinomyces, Veillonella, and Escherichia coli revealed an increased amount in patients with Crohn's disease. For patients with ulcerative colitis, Eubacterium rectale and Akkermansia were decreased in all 3 studies, whereas E coli was increased in 4 of 9 studies. The microbiota diversity was either decreased or not different in patients with IBD vs controls. Fewer than 50% of the studies stated comparable sexes and ages of cases and controls.
CONCLUSIONS
In a systematic review, we found evidence for differences in abundances of some bacteria in patients with IBD vs controls, but we cannot make conclusions due to inconsistent results and methods among studies. Further large-scale studies, with better methods of assessing microbe populations, are needed.
Topics: Colitis, Ulcerative; Crohn Disease; Feces; Gastrointestinal Microbiome; Humans; Inflammatory Bowel Diseases; Intestines
PubMed: 31812509
DOI: 10.1053/j.gastro.2019.11.294 -
A systematic review on the role of microbiota in the pathogenesis and treatment of eating disorders.European Psychiatry : the Journal of... Dec 2020There is growing interest in new factors contributing to the genesis of eating disorders (EDs). Research recently focused on the study of microbiota. Dysbiosis,...
BACKGROUND
There is growing interest in new factors contributing to the genesis of eating disorders (EDs). Research recently focused on the study of microbiota. Dysbiosis, associated with a specific genetic susceptibility, may contribute to the development of anorexia nervosa (AN), bulimia nervosa, or binge eating disorder, and several putative mechanisms have already been identified. Diet seems to have an impact not only on modification of the gut microbiota, facilitating dysbiosis, but also on its recovery in patients with EDs.
METHODS
This systematic review based on the PICO strategy searching into PubMed, EMBASE, PsychINFO, and Cochrane Library examined the literature on the role of altered microbiota in the pathogenesis and treatment of EDs.
RESULTS
Sixteen studies were included, mostly regarding AN. Alpha diversity and short-chain fatty acid (SCFA) levels were lower in patients with AN, and affective symptoms and ED psychopathology seem related to changes in gut microbiota. Microbiota-derived proteins stimulated the autoimmune system, altering neuroendocrine control of mood and satiety in EDs. Microbial richness increased in AN after weight regain on fecal microbiota transplantation.
CONCLUSIONS
Microbiota homeostasis seems essential for a healthy communication network between gut and brain. Dysbiosis may promote intestinal inflammation, alter gut permeability, and trigger immune reactions in the hunger/satiety regulation center contributing to the pathophysiological development of EDs. A restored microbial balance may be a possible treatment target for EDs. A better and more in-depth characterization of gut microbiota and gut-brain crosstalk is required. Future studies may deepen the therapeutic and preventive role of microbiota in EDs.
Topics: Affect; Anorexia Nervosa; Binge-Eating Disorder; Brain; Bulimia Nervosa; Feeding and Eating Disorders; Gastrointestinal Microbiome; Humans; Psychopathology; Satiety Response
PubMed: 33416044
DOI: 10.1192/j.eurpsy.2020.109 -
International Journal of Molecular... Dec 2021The human microbiome plays a crucial role in determining the health status of every human being, and the microbiome of the genital tract can affect the fertility...
The human microbiome plays a crucial role in determining the health status of every human being, and the microbiome of the genital tract can affect the fertility potential before and during assisted reproductive treatments (ARTs). This review aims to identify and appraise studies investigating the correlation of genital microbiome to infertility. Publications up to February 2021 were identified by searching the electronic databases PubMed/MEDLINE, Scopus and Embase and bibliographies. Only full-text original research articles written in English were considered eligible for analysis, whereas reviews, editorials, opinions or letters, case studies, conference papers, and abstracts were excluded. Twenty-six articles were identified. The oldest studies adopted the exclusive culture-based technique, while in recent years PCR and RNA sequencing based on 16S rRNA were the most used technique. Regardless of the anatomical site under investigation, the -dominated flora seems to play a pivotal role in determining fertility, and in particular showed a central role. Nonetheless, the presence of pathogens in the genital tract, such as , , species, and Gram-negative stains microorganism, affected fertility also in case of asymptomatic bacterial vaginosis (BV). We failed to identify descriptive or comparative studies regarding tubal microbiome. The microbiome of the genital tract plays a pivotal role in fertility, also in case of ARTs. The standardization of the sampling methods and investigations approaches is warranted to stratify the fertility potential and its subsequent treatment. Prospective tubal microbiome studies are warranted.
Topics: Cervix Uteri; Endometrium; Female; Genitalia, Female; Humans; Infertility, Female; Lactobacillus; Microbiota; Vagina
PubMed: 35008605
DOI: 10.3390/ijms23010180 -
Clinical Microbiology and Infection :... Sep 2023The clinical usefulness of follow-up blood cultures (FUBCs) in gram-negative bloodstream infections (GN-BSIs) represents a debated issue. (Meta-Analysis)
Meta-Analysis Review
Impact on clinical outcome of follow-up blood cultures and risk factors for persistent bacteraemia in patients with gram-negative bloodstream infections: a systematic review with meta-analysis.
BACKGROUND
The clinical usefulness of follow-up blood cultures (FUBCs) in gram-negative bloodstream infections (GN-BSIs) represents a debated issue.
OBJECTIVE
To assess the impact on the clinical outcome of FUBCs in patients with GN-BSI and to predict risk factors for persistent bacteraemia.
DATA SOURCES
PubMed-MEDLINE, Scopus, and the Cochrane Library Database were independently searched until 24 June, 2022.
STUDY ELIGIBILITY CRITERIA
Randomized controlled trials, prospective, or retrospective observational studies, including patients affected by GN-BSIs. Primary endpoints were in-hospital mortality rate, and persistent blood stream infections were defined as FUBC-positive for the same pathogen isolated from index blood cultures (BCs).
PARTICIPANTS
Hospitalized patients with documented GN-BSIs.
INTERVENTION
Performance of FUBCs (defined as subsequent BCs collected at least 24 hours after index BCs).
ASSESSMENT OF RISK OF BIAS
Quality of included studies was independently assessed according to the Cochrane Risk of Bias Tool and the Risk Of Bias In Non-randomized Studies of Interventions.
METHODS OF DATA SYNTHESIS
Meta-analysis was performed by pooling odds ratio (OR) retrieved from studies providing adjustment for confounders using random-effect model with the inverse variance method. Risk factors for persistent blood stream infections were also assessed.
RESULTS
A total of 3747 articles were screened, and 11 observational studies (6 assessing impact on outcome (N = 4631), and 5 investigating risk factors for persistent GN-BSI (N = 2566)), conducted between 2002 and 2020 were included. The execution of FUBCs was associated with a significantly lower risk of mortality (OR, 0.58; 95% CI, 0.49-0.70; I = 0.0%). The presence of end-stage renal disease (OR, 2.99; 95% CI, 1.77-5.05), central venous catheter (OR, 3.30; 95% CI, 1.82-5.95), infections due to extended-spectrum β-lactamase-producing strains (OR, 2.25; 95% CI, 1.18-4.28), resistance to empirical treatment (OR, 2.70; 95% CI, 1.65-4.41), and unfavourable response at 48 hours (OR, 2.99; 95% CI, 1.44-6.24) emerged as independent risk factors for persistent bacteraemia.
CONCLUSIONS
The execution of FUBCs is associated with a significantly low risk of mortality in patients with GN-BSIs. Our analysis could be useful to stratify patients at a high risk of persistent bacteraemia to optimize the use of FUBCs.
Topics: Humans; Retrospective Studies; Follow-Up Studies; Prospective Studies; Blood Culture; Bacteremia; Sepsis; Risk Factors
PubMed: 36894053
DOI: 10.1016/j.cmi.2023.02.024 -
BJOG : An International Journal of... Jan 2020Vaginal probiotics claiming to cure and/or prevent bacterial and/or fungal vaginal dysbiosis are available on the market but, until recently, did not have to be approved...
BACKGROUND
Vaginal probiotics claiming to cure and/or prevent bacterial and/or fungal vaginal dysbiosis are available on the market but, until recently, did not have to be approved as drugs for human use.
OBJECTIVES
We evaluated the impact of vaginal probiotics on bacterial vaginosis (BV) and vulvovaginal candidiasis (VVC) cure and/or recurrence, as well as vaginal microbiota (VMB) composition and vaginal detection of probiotic strains.
SEARCH STRATEGY
We performed a systematic literature search in MEDLINE and Embase up to 15 January 2019.
SELECTION CRITERIA
There were no restrictions in probiotic strains/formulations, study populations, and designs. BV had to be diagnosed by Nugent or Ison-Hay Gram stain scoring, VVC by culture, wet mount or PCR, and VMB composition/detection by molecular techniques.
DATA COLLECTION AND ANALYSIS
The authors independently extracted data.
MAIN RESULTS
All 22 vaginal probiotics evaluated in the 34 eligible studies contained Lactobacillus strains, and some contained additional active ingredients. The probiotics hold promise for BV cure and prevention, but much less so for VVC cure and prevention. No major safety concerns were reported in any of the studies. Vaginal detection of probiotic strains never lasted long beyond the dosing period, suggesting that they did not colonise the vagina. However, findings are not definitive because heterogeneity was high and the quality of most studies suboptimal.
CONCLUSIONS
Availability of vaginal probiotics for vaginal health indications will likely decline in 2020 because of regulatory changes. We urge the field to invest in clinical evidence-based product development and to conduct future trials more rigorously.
TWEETABLE ABSTRACT
Lactobacilli-containing vaginal probiotics hold promise for bacterial vaginosis cure and prevention, but not for vulvovaginal candidiasis.
Topics: Candidiasis, Vulvovaginal; Dysbiosis; Female; Humans; Lactobacillus; Microbiota; Probiotics; Treatment Outcome; Vagina; Vaginosis, Bacterial
PubMed: 31299136
DOI: 10.1111/1471-0528.15870 -
Clinical Microbiology and Infection :... Dec 2020Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbidity and mortality. The prevalence of bacterial infection... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Bacterial co-pathogens are commonly identified in viral respiratory infections and are important causes of morbidity and mortality. The prevalence of bacterial infection in patients infected with SARS-CoV-2 is not well understood.
AIMS
To determine the prevalence of bacterial co-infection (at presentation) and secondary infection (after presentation) in patients with COVID-19.
SOURCES
We performed a systematic search of MEDLINE, OVID Epub and EMBASE databases for English language literature from 2019 to April 16, 2020. Studies were included if they (a) evaluated patients with confirmed COVID-19 and (b) reported the prevalence of acute bacterial infection.
CONTENT
Data were extracted by a single reviewer and cross-checked by a second reviewer. The main outcome was the proportion of COVID-19 patients with an acute bacterial infection. Any bacteria detected from non-respiratory-tract or non-bloodstream sources were excluded. Of 1308 studies screened, 24 were eligible and included in the rapid review representing 3338 patients with COVID-19 evaluated for acute bacterial infection. In the meta-analysis, bacterial co-infection (estimated on presentation) was identified in 3.5% of patients (95%CI 0.4-6.7%) and secondary bacterial infection in 14.3% of patients (95%CI 9.6-18.9%). The overall proportion of COVID-19 patients with bacterial infection was 6.9% (95%CI 4.3-9.5%). Bacterial infection was more common in critically ill patients (8.1%, 95%CI 2.3-13.8%). The majority of patients with COVID-19 received antibiotics (71.9%, 95%CI 56.1 to 87.7%).
IMPLICATIONS
Bacterial co-infection is relatively infrequent in hospitalized patients with COVID-19. The majority of these patients may not require empirical antibacterial treatment.
Topics: Asia; Bacteria; Bacterial Infections; COVID-19; Coinfection; Critical Illness; Data Management; Female; Humans; Male; Pandemics; Prevalence; Respiratory Tract Infections; United States
PubMed: 32711058
DOI: 10.1016/j.cmi.2020.07.016