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Medicine Sep 2023Accumulating evidence has indicated a possible connection between post-stroke cognitive impairment (PSCI) and gut microbiota imbalance. To further investigate this... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Accumulating evidence has indicated a possible connection between post-stroke cognitive impairment (PSCI) and gut microbiota imbalance. To further investigate this association, the present work was designed to systematically assess the dissimilarity of gut microbiota between PSCI and healthy individuals or stroke patients.
METHODS
A meta-analysis and systematic review was conducted by searching various databases including PubMed, Web of Science, Embase, VIP, CNKI, and Wangfang for relevant studies. The pooled outcomes were used to estimate the combined dissimilarity of gut microbiota composition between PSCI and healthy individuals or patients with stroke.
RESULTS
Nine eligible studies were included in this meta-analysis. The results showed that there were no significant changes in observed richness indexes (Chao1 and ACE) and Shannon index. Notably, a significant decrease in Simpson index was observed in PSCI patients in comparison to the healthy individuals (-0.31, 95% CI: -0.62 to -0.01, P = 0.04). Moreover, the microbiota composition at the phylum level (increased abundance of Proteobacteria), family level (increased abundance of Bacteroidaceae, Lachnospiraceae, and Veillonellaceae; decreased abundance of Enterobacteriaceae), and genus level (increased abundance of Bacteroides, Clostridium XIVa, and Parabacteroides; decreased abundance of Prevotella and Ruminococcus) was found to be significantly different between PSCI and controls.
CONCLUSION
This meta-analysis suggests a significant shift of observed species and microbiota composition in PSCI compared to healthy individuals or patients with stroke.
Topics: Humans; Gastrointestinal Microbiome; Microbiota; Bacteroides; Clostridiales; Cognitive Dysfunction; Stroke
PubMed: 37657030
DOI: 10.1097/MD.0000000000034764 -
Molecular Psychiatry Dec 2023A body of pre-clinical evidence shows how the gut microbiota influence brain functioning, including brain connectivity. Linking measures of brain connectivity to the gut...
A body of pre-clinical evidence shows how the gut microbiota influence brain functioning, including brain connectivity. Linking measures of brain connectivity to the gut microbiota can provide important mechanistic insights into the bi-directional gut-brain communication. In this systematic review, we therefore synthesized the available literature assessing this association, evaluating the degree of consistency in microbiota-connectivity associations. Following the PRISMA guidelines, a PubMed search was conducted, including studies published up to September 1, 2022. We identified 16 studies that met the inclusion criteria. Several bacterial genera, including Prevotella, Bacteroides, Ruminococcus, Blautia, and Collinsella were most frequently reported in association with brain connectivity. Additionally, connectivity of the salience (specifically the insula and anterior cingulate cortex), default mode, and frontoparietal networks were most frequently associated with the gut microbiota, both in terms of microbial diversity and composition. There was no discernible pattern in the association between microbiota and brain connectivity. Altogether, based on our synthesis, there is evidence for an association between the gut microbiota and brain connectivity. However, many findings were poorly replicated across studies, and the specificity of the association is yet unclear. The current studies show substantial inter-study heterogeneity in methodology and reporting, limiting the robustness and reproducibility of the findings and emphasizing the need to harmonize methodological approaches. To enhance comparability and replicability, future research should focus on further standardizing processing pipelines and employing data-driven multivariate analysis strategies.
Topics: Humans; Gastrointestinal Microbiome; Brain; Brain-Gut Axis; Connectome; Nerve Net
PubMed: 37479779
DOI: 10.1038/s41380-023-02146-4 -
Journal of Gastrointestinal and Liver... Sep 2023Traditional cardiovascular risk factors are established predictors of heart failure (HF). However, the human gut microbiota is suggested to potentially interact with the...
BACKGROUND AND AIMS
Traditional cardiovascular risk factors are established predictors of heart failure (HF). However, the human gut microbiota is suggested to potentially interact with the cardiovascular system through the "gut-heart axis", which induces inflammation and contributes to HF pathogenesis. This systematic review aims to confirm the interconnection between the gut microbiome in HF patients.
METHODS
Peer-reviewed human studies comparing the gut microbiota profile in adult patients with HF and healthy controls (HCs) up to April 18, 2022, were searched in Ovid MEDLINE, Ovid EMBASE, SCOPUS, and the Cochrane Library. The quality of the included studies was assessed using the Newcastle-Ottawa Scale (NOS).
RESULTS
A total of nine studies, including 317 HF patients and 510 HCs, were included in the review. Decreased gut microbiota richness and similar microbial diversity (alpha diversity), and significantly different gut microbiota composition (beta diversity) were observed between HF patients and HCs. In comparison to HCs, HF patients had a greater abundance of Actinobacteria, Proteobacteria, and Synergistetes phyla; Enterococcus, Escherichia, Klebsiella, Lactobacillus, Streptococcus, and Veilonella genera and Ruminococcus gnavus, Streptococcus sp., and Veilonella sp. species. In contrast, there was decreased abundance of Firmicutes phylum; Blautia, Eubacterium, Faecalibacterium, and Lachnospiraceae FCS020 genera; and Dorea longicatena, Eubacterium rectale, Faecalibacterium prausnitzii, Oscillibacter sp., and Sutterella wadsworthensis species in HF patients.
CONCLUSIONS
Gut microbiota diversity, richness, and composition in HF patients differ significantly from the healthy population. Overall, short-chain fatty acid (SCFA)-producing gut microbiota was depleted in HF patients. However, different underlying comorbidities, environments, lifestyles, and dietary choices could affect gut microbiota heterogeneity.
Topics: Adult; Humans; Gastrointestinal Microbiome; Diet; Bacteria; Heart Failure; Inflammation
PubMed: 37774217
DOI: 10.15403/jgld-4779 -
Diagnostic Microbiology and Infectious... Jul 2024Increasing evidence has indicated dysbiosis of the gut microbiota in patients with pulmonary tuberculosis (PTB). However, the change in the intestinal microbiota varies... (Review)
Review
Increasing evidence has indicated dysbiosis of the gut microbiota in patients with pulmonary tuberculosis (PTB). However, the change in the intestinal microbiota varies between different studies. This systematic review was conducted to investigate the characteristics of the gut microbiota in PTB patients. The MBASE, MEDLINE, Web of Science, and Cochrane Library electronic databases were systematically searched, and the quality of the retrieved studies was evaluated using the Newcastle-Ottawa scale. A total of 12 studies were finally included in the systematic review. Compared with healthy controls, the index reflecting α-diversity including the richness and/or diversity index decreased in 6 studies, while β-diversity presented significant differences in PTB patients in 10 studies. Although the specific gut microbiota alterations were inconsistent, short-chain fatty acid-producing bacteria (including Lachnospiraceae, Ruminococcus, Blautia, Dorea, and Faecalibacterium), bacteria associated with an inflammatory state (e.g., Prevotellaceae and Prevotella), and beneficial bacteria (e.g., Bifidobacteriaceae and Bifidobacterium) were commonly noted. Our systematic review identifies key evidence for gut microbiota alterations in PTB patients, in comparison with healthy controls; however, no consistent conclusion could be drawn, due to the inconsistent results and heterogeneous methodologies of the enrolled studies. Therefore, more well-designed research with standard methodologies and large sample sizes is required.
Topics: Humans; Gastrointestinal Microbiome; Tuberculosis, Pulmonary; Dysbiosis; Bacteria
PubMed: 38581928
DOI: 10.1016/j.diagmicrobio.2024.116291 -
Clinical and Experimental... 2024The diagnosis of irritable bowel syndrome (IBS) is based on symptom-based criteria due to lack of reliable disease-specific biomarkers. Gut microbiota is perturbed in... (Review)
Review
A Systematic Review: Fecal Bacterial Profile in Patients with Irritable Bowel Syndrome Analyzed with the GA-Map Dysbiosis Test Based on the 16S rRNA Gene of Bacterial Species or Groups.
PURPOSE
The diagnosis of irritable bowel syndrome (IBS) is based on symptom-based criteria due to lack of reliable disease-specific biomarkers. Gut microbiota is perturbed in IBS and when comparing different methods used to analyze gut microbiota, the results might be obscured. Therefore, in this systematic review we aimed to investigate the profile of fecal bacterial markers and dysbiosis index (DI) in patients with IBS and IBS subgroups compared to healthy controls (HCs) conducted by the same method (GA-map Dysbiosis Test based on16S rRNA sequencing).
MATERIAL AND METHOD
We searched PubMed, EMBASE (Ovid) and Cochrane Library for case-control studies comparing fecal gut microbiota analyzed with the GA-map Dysbiosis Test (Oslo, Norway) in patients with IBS and HCs. Our outcomes were the difference in fecal bacterial markers and DI in patients with IBS and IBS subgroups compared to HCs.
RESULTS
The search identified 28 citations; five articles were included. Most studies evaluated fecal bacterial markers and DI in patients with diarrhea-predominant IBS (IBS-D). Results of fecal bacteria profile in IBS and IBS subgroups compared to HCs are inconsistent, however, two studies showed increased levels of in IBS-D compared to HCs and results of DI indicated IBS and IBS subgroups (especially IBS-D) having higher DI compared to HCs.
CONCLUSION
This systematic review revealed inconsistent findings in respect to differences in bacterial markers between IBS and IBS subgroups with HCs in studies using the GA-map Dysbiosis Test based on 16S rRNA sequencing. However, the test is quite novel, and few studies have used the method so far. More research comparing fecal microbiota profile differences in IBS and IBS subgroups compared to HCs utilizing the same method of analysis is needed to give us further insight into the gut bacteria profile in IBS and the clinical consequences of intestinal dysbiosis.
PubMed: 38646157
DOI: 10.2147/CEG.S451675 -
PloS One 2024Alterations in the composition and abundance of the intestinal microbiota occur in non-alcoholic fatty liver disease (NAFLD). However, the results are inconsistent... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Alterations in the composition and abundance of the intestinal microbiota occur in non-alcoholic fatty liver disease (NAFLD). However, the results are inconsistent because of differences in the study design, subject area, and sequencing methodology. In this study, we compared the diversity and abundance of the intestinal microbiota of patients with NAFLD and healthy individuals through a systematic review and meta-analysis.
METHODS
Three databases (PubMed, EMBASE, and Cochrane Library) were searched from their inception to March 20, 2023. A meta-analysis was performed using Stata software to analyze variations in the richness and abundance of the intestinal microbiota in patients with NAFLD. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used for quality assessment.
RESULTS
A total of 28 articles were included. Shannon diversity was reduced in patients with NAFLD (SMD = -0.24 (95% CI -0.43-0.05, I2 = 71.7%). The relative abundance of Ruminococcus, Faecalibacterium, and Coprococcus all decreased, with total SMDs of -0.96 (95% CI -1.29 to -0.63, I2 = 4.8%), -1.13 (95% CI -2.07 to -0.19, I2 = 80.5%), and -1.66 (95% CI -3.04 to -0.28, I2 = 91.5%). Escherichia was increased in individuals with NAFLD (SMD = 1.78, 95% CI 0.12 to 3.45, I2 = 94.4%).
CONCLUSION
Increasing the species diversity and altering the abundance of specific gut microbiota, including Coprococcus, Faecalibacterium, Ruminococcus, and Escherichia, may be beneficial for improving NAFLD.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Gastrointestinal Microbiome; Gram-Positive Cocci; Faecalibacterium; Research Design; Clostridiales
PubMed: 38547205
DOI: 10.1371/journal.pone.0299946