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Schizophrenia Research Aug 2021Schizophrenia and bipolar disorder (BD) are associated with debilitating psychiatric and cognitive dysfunction, worse health outcomes, and shorter life expectancies. The...
Schizophrenia and bipolar disorder (BD) are associated with debilitating psychiatric and cognitive dysfunction, worse health outcomes, and shorter life expectancies. The pathophysiological understanding of and therapeutic resources for these neuropsychiatric disorders are still limited. Humans harbor over 1000 unique bacterial species in our gut, which have been linked to both physical and mental/cognitive health. The gut microbiome is a novel and promising avenue to understand the attributes of psychiatric diseases and, potentially, to modify them. Building upon our previous work, this systematic review evaluates the most recent evidence of the gut microbiome in clinical populations with serious mental illness (SMI). Sixteen articles that met our selection criteria were reviewed, including cross-sectional cohort studies and longitudinal treatment trials. All studies reported alterations in the gut microbiome of patients with SMI compared to non-psychiatric comparison subjects (NCs), and beta-diversity was consistently reported to be different between schizophrenia and NCs. Ruminococcaceae and Faecalibacterium were relatively decreased in BD, and abundance of Ruminococcaceae was reported across several investigations of SMI to be associated with better clinical characteristics. Lactic acid bacteria were relatively more abundant in SMI and associated with worse clinical outcomes. There was very limited evidence for the efficacy of probiotic or prebiotic interventions in SMI. As microbiome research in psychiatry is still nascent, the extant literature has several limitations. We critically evaluate the current data, including experimental approaches. There is a need for more unified methodological standards in order to arrive at robust biological understanding of microbial contributions to SMI.
Topics: Bipolar Disorder; Cross-Sectional Studies; Gastrointestinal Microbiome; Humans; Mental Disorders; Schizophrenia
PubMed: 31495702
DOI: 10.1016/j.schres.2019.08.026 -
Pancreatology : Official Journal of the... Jan 2021Altered intestinal microbiota has been reported in pancreatic disorders, however, it remains unclear whether these changes alter the course of disease in patients with...
BACKGROUND
Altered intestinal microbiota has been reported in pancreatic disorders, however, it remains unclear whether these changes alter the course of disease in patients with acute (AP) and chronic pancreatitis (CP), or whether these disease states alter the environment to enable pathogenic microbial composition changes to occur. We undertook a systematic review to characterize the gut microbiome in pancreatitis patients.
METHODS
MEDLINE and EMBASE were searched for studies on microbiota in pancreatitis published from January 1, 2000 to June 5, 2020. Animal studies, reviews, case reports, and non-English articles were excluded. A frequency analysis was performed for outcomes reported in ≥2 studies and studies were analyzed for risk of bias and quality of evidence.
RESULTS
22 papers met inclusion criteria; 15 included AP, 7 included CP. No studies were appropriately designed to assess whether alterations in the gut microbiome exacerbate pancreatitis or develop as a result of pancreatitis. We did identify several patterns of microbiome changes that are associated with pancreatitis. The gut microbiome demonstrated decreased alpha diversity in 3/3 A P studies and 3/3 C P studies. Beta diversity analysis revealed differences in bacterial community composition in the gut microbiome in 2/2 A P studies and 3/3 C P studies. Functionally, gut microbiome changes were associated with infectious pathways in AP and CP. Several studies suffered from high risk of bias and inadequate quality.
CONCLUSIONS
Detecting differences in microbial composition associated with AP and CP may represent a diagnostic tool. Appropriately controlled longitudinal studies are needed to determine whether microbiome changes are causative or reactive in pancreatitis.
Topics: Gastrointestinal Microbiome; Humans; Pancreatitis; Pancreatitis, Chronic
PubMed: 33376062
DOI: 10.1016/j.pan.2020.12.013 -
Viruses Jan 2024Respiratory syncytial virus (RSV) infection is a major cause of lower respiratory tract infection, especially in infants, and increases the risk of recurrent wheezing... (Review)
Review
BACKGROUND
Respiratory syncytial virus (RSV) infection is a major cause of lower respiratory tract infection, especially in infants, and increases the risk of recurrent wheezing and asthma. Recently, researchers have proposed a possible association between respiratory diseases and microbiome alterations. However, this connection has not been fully established. Herein, we conducted a systematic literature review to evaluate the reported evidence of microbiome alterations in patients with RSV infection.
METHODS
The systematic literature review on the association between RSV and microbiome in humans was conducted by searching PubMed, EMBASE, Scopus, and CINAHL from 2012 until February 2022. The results were analyzed qualitatively, focusing on the relationship between microbiome and RSV infection with available key microbiome-related parameters.
RESULTS
In the 405 articles identified by searching databases, 12 (Respiratory tract: 9, Gut: 2, Both: 1) articles in line with the research aims were eligible for this qualitative review. The types of samples for the respiratory tract microbiome and the sequencing methods utilized varied from study to study. This review revealed that the overall microbial composition in both the respiratory tract and gut in RSV-infected patients was different from that in healthy controls. Our generated results demonstrated an increase in the abundance of and , which could contribute to the distinctive separation based on the beta diversity in the respiratory tract.
CONCLUSIONS
The respiratory tract and gut microbiome changed in patients with RSV infection. Further research with a well-organized longitudinal design is warranted to clarify the impact of microbiome alterations on disease pathogenesis.
Topics: Infant; Humans; Respiratory Syncytial Virus Infections; Gastrointestinal Microbiome; Respiratory Tract Infections; Microbiota; Asthma
PubMed: 38399997
DOI: 10.3390/v16020220 -
Medicina Oral, Patologia Oral Y Cirugia... May 2022Oral mucositis is one of the most common side effects in cancer patients receiving systemic antineoplastics. However, the underlying biological mechanisms leading to...
BACKGROUND
Oral mucositis is one of the most common side effects in cancer patients receiving systemic antineoplastics. However, the underlying biological mechanisms leading to this condition are still unclear. For this reason, it has been hypothesised that systemic antineoplastics may cause an imbalance on the oral microbiota that subsequently triggers oral mucosa damage.
MATERIAL AND METHODS
A systematic review was performed following the PRISMA protocol and the PICO question established was: patients diagnosed with cancer, who are candidates for receiving systemic antineoplastics (P=Patients), that undergo oral microbiome determinations (I=Intervention), before and after systemic antineoplastics administration (C=Comparison), to analyse changes in the oral microbiome composition (O=Outcome). The bibliographic search was carried out in PubMed and other scientific repositories.
RESULTS
Out of 166 obtained articles, only 5 met eligibility criteria. Acute myeloid leukaemia (AML) was the most frequent type of cancer (40 %) among the participants. Only one of the studies included a control group of healthy subjects. Heterogeneity in the protocols and approaches of the included studies hindered a detailed comparison of the outcomes. However, it was stated that a decrease in bacteria α diversity is often associated with oral mucositis. On the other hand, fungal diversity was not associated with oral mucositis although α diversity was lower at baseline on patients developing oral candidiasis.
CONCLUSIONS
There is insufficient scientific evidence of oral microbiological changes in patients undergoing systemic antineoplastics. Further investigations ought to be carried out to identify microorganisms that might play a key role in the pathogenesis of oral mucosa damage in patients undergoing systemic antineoplastics.
Topics: Antineoplastic Agents; Candidiasis, Oral; Humans; Microbiota; Neoplasms; Stomatitis
PubMed: 35368011
DOI: 10.4317/medoral.25121 -
Head & Neck Aug 2023The relationship between head and neck squamous cell carcinoma (HNSCC) and the oral microbiome has been drawn in various studies. Microbial diversities, microbiome... (Review)
Review
OBJECTIVES
The relationship between head and neck squamous cell carcinoma (HNSCC) and the oral microbiome has been drawn in various studies. Microbial diversities, microbiome profiles, metagenomic analysis, and host-pathogen interactions were collected from these studies to highlight similarities and account for inconsistencies. We also evaluate the possible clinical applications of the microbiome regarding screening and diagnosis of HNSCC.
METHODS
Systematic analysis of studies regarding HNSCC and the microbiome was done according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines. Articles were retrieved from four databases (PubMed, ScienceDirect, CUHK Full-Text Journals, and Cochrane database) and were screened using predefined criteria.
RESULTS
Twenty studies were chosen after screening for full-text review. α-diversity comparison was inconsistent whereas β-diversity between HNSCC and normal samples showed distinct clustering. Microbial dysbiosis characterized by change in the relative abundances of several bacterial species were also seen in HNSCC patients. At a phylum level, inconsistencies were seen between studies using HNSCC tumor tissue samples and saliva samples. At a genus level, Fusobacterium, Peptostreptococcus, Alloprevotella, Capnocytophaga, Catonella, and Prevotella were differentially enriched in HNSCC while Streptococcus, Actinomyces Veillonella, and Rothia were differentially depleted. Co-occurrence network analysis revealed a positive correlation of HNSCC with periodontal pathogens and a negative correlation with commensal bacteria. Metagenomic analysis of microbiota revealed a differential enrichment of pro-inflammatory genomic pathways which was consistent across various studies. Microbial dysbiosis was applied in clinical use as a tool for HNSCC screening. Random-forest analysis was adopted to differentiate between tumor and normal tissue, at 95.7% and 70.0% accuracies respectively in two studies. Microbial dysbiosis index was also used to predict prognosis.
CONCLUSIONS
Oral microbial dysbiosis could be a promising tool for HNSCC screening and diagnosis. However, more research should be conducted pertaining to clinical applications to improve diagnostic accuracy and explore other clinical uses.
Topics: Humans; Bacteria; Dysbiosis; Head and Neck Neoplasms; Microbiota; Squamous Cell Carcinoma of Head and Neck
PubMed: 37249085
DOI: 10.1002/hed.27422 -
BMC Geriatrics Jun 2023The characterization and research around the gut microbiome in older people emphasize microbial populations change considerably by losing the diversity of species. Then,...
BACKGROUND
The characterization and research around the gut microbiome in older people emphasize microbial populations change considerably by losing the diversity of species. Then, this review aims to determine if there is any effect on the gut microbiota of adults older than 65 that starts an exercise intervention or improves physical activity level. Also, this review describes the changes in composition, diversity, and function of the gut microbiota of older subjects that had improved their physical activity level.
METHODS
The type of studies included in this review were studies describing human gut microbiota responses to any exercise stimulus; cross-sectional studies focused on comparing gut microbiota in older adults with different physical activity levels-from athletes to inactive individuals; studies containing older people (women and men), and studies written in English. This review's primary outcomes of interest were gut microbiota abundance and diversity.
RESULTS
Twelve cross-sectional studies and three randomized controlled trials were examined. Independently of the type of study, diversity metrics from Alpha and Beta diversity remained without changes in almost all the studies. Likewise, cross-sectional studies do not reflect significant changes in gut microbiota diversity; no significant differences were detected among diverse groups in the relative abundances of the major phyla or alpha diversity measures. Otherwise, relative abundance analysis showed a significant change in older adults who conducted an exercise program for five weeks or more at the genus level.
CONCLUSIONS
Here, we did not identify significant shifts in diversity metrics; only one study reported a significant difference in Alpha diversity from overweight people with higher physical activity levels. The abundance of some bacteria is higher in aged people, after an exercise program, or in comparison with control groups, especially at the genus and species levels. There needs to be more information related to function and metabolic pathways that can be crucial to understand the effect of exercise and physical activity in older adults.
TRIAL REGISTRATION
PROSPERO ID: CRD42022331551.
Topics: Male; Humans; Female; Aged; Gastrointestinal Microbiome; Cross-Sectional Studies; Exercise; Sedentary Behavior
PubMed: 37308839
DOI: 10.1186/s12877-023-04066-y -
Gastroenterology Jul 2019Irritable bowel syndrome (IBS) is common but difficult to treat. Altering the gut microbiota has been proposed as a strategy for treatment of IBS, but the association...
BACKGROUND & AIMS
Irritable bowel syndrome (IBS) is common but difficult to treat. Altering the gut microbiota has been proposed as a strategy for treatment of IBS, but the association between the gut microbiome and IBS symptoms has not been well established. We performed a systematic review to explore evidence for this association.
METHODS
We searched databases, including MEDLINE, EMBASE, Cochrane CDSR, and CENTRAL, through April 2, 2018 for case-control studies comparing the fecal or colon microbiomes of adult or pediatric patients with IBS with microbiomes of healthy individuals (controls). The primary outcome was differences in specific gut microbes between patients with IBS and controls.
RESULTS
The search identified 2631 citations; 24 studies from 22 articles were included. Most studies evaluated adults presenting with various IBS subtypes. Family Enterobacteriaceae (phylum Proteobacteria), family Lactobacillaceae, and genus Bacteroides were increased in patients with IBS compared with controls, whereas uncultured Clostridiales I, genus Faecalibacterium (including Faecalibacterium prausnitzii), and genus Bifidobacterium were decreased in patients with IBS. The diversity of the microbiota was either decreased or not different in IBS patients compared with controls. More than 40% of included studies did not state whether cases and controls were comparable (did not describe sex and/or age characteristics).
CONCLUSIONS
In a systematic review, we identified specific bacteria associated with microbiomes of patients with IBS vs controls. Studies are needed to determine whether these microbes are a product or cause of IBS.
Topics: Bacteroides; Bifidobacterium; Clostridiales; Enterobacteriaceae; Faecalibacterium; Gastrointestinal Microbiome; Humans; Irritable Bowel Syndrome; Lactobacillaceae
PubMed: 30940523
DOI: 10.1053/j.gastro.2019.03.049 -
Frontiers in Endocrinology 2022Gestational diabetes mellitus (GDM) is a metabolic disorder that might predispose pregnant women to develop type 2 Diabetes Mellitus or lead to severe adverse outcomes...
AIMS
Gestational diabetes mellitus (GDM) is a metabolic disorder that might predispose pregnant women to develop type 2 Diabetes Mellitus or lead to severe adverse outcomes in their offspring. One of the factors that have been thought to be involved in the pathology behind this disorder is the microbiome. In this systematic review, we comprehensively review the documents regarding the microbiota alterations in different tracts of pregnant women with GDM and their offspring.
METHODS
A comprehensive search was conducted in major databases including MEDLINE (PubMed), Scopus, and Web of sciences up to August 2021. Data on the demographics, methodology, and microbiome alterations were extracted and classified according to the type of microbiome in pregnant women with GDM and their offspring. The quality of studies was assessed using the Newcastle-Ottawa Scale (NOS).
RESULTS
In 49 articles which were retrieved, the findings were variable on the level of changes in alpha and beta diversity, enrichment or depletion in phyla, genera, species and OTUs, in each microbiome type. Although there were some inconsistencies among the results, a pattern of significant alterations was seen in the gut, oral, vaginal microbiome of women with GDM and gut, oral, and placental microbiome of their offspring.
CONCLUSION
Even though the alteration of the microbiome of the different tracts was seen in the cases of GDM, the inconsistency among the studies prevents us from identifying unique pattern. However, the results seem promising and further studies that overcome the confounding factors related to the demographics and methodology are needed.
Topics: Humans; Pregnancy; Female; Diabetes, Gestational; Diabetes Mellitus, Type 2; Placenta; Microbiota; Pregnancy Trimester, Third
PubMed: 36568098
DOI: 10.3389/fendo.2022.1060488 -
American Journal of Rhinology & Allergy 2016Our understanding of the resident microbiome of the paranasal sinuses has changed considerably in recent years. Once presumed to be sterile, healthy sinus cavities are... (Review)
Review
BACKGROUND
Our understanding of the resident microbiome of the paranasal sinuses has changed considerably in recent years. Once presumed to be sterile, healthy sinus cavities are now known to harbor a diverse assemblage of microorganisms, and, it is hypothesized that alterations in the kinds and quantities of these microbes may play a role in the pathogenesis of chronic rhinosinusitis (CRS).
OBJECTIVES
To review the current literature regarding the sinus microbiome and collate research findings from relevant studies published to date.
METHODS
A systematic literature review was performed on all molecular studies that investigated the microbial communities of the paranasal sinuses. Methods of detection, microbiome composition, and comparative profiling between patients with and without CRS were explored.
RESULTS
A complex consortium of microorganisms has been demonstrated in the sinuses of both patients with and without CRS. However, the latter generally have been characterized by reduced biodiversity compared with controls, with selective enrichment of particular microbes (e.g., Staphylococcus aureus). Such disruptions in the resident microbiome may contribute to disease pathogenesis by enhancing the virulence of potential pathogens and adversely modulating immune responses.
CONCLUSION
The advent of culture-independent molecular approaches has led to a greater appreciation of the intricate microbial ecology of the paranasal sinuses. Microbiota composition, distribution, and abundance impact mucosal health and influence pathogen growth and function. A deeper understanding of the host-microbiome relationship and its constituents may encourage development of new treatment paradigms for CRS, which target restoration of microbiome homeostasis and cultivation of optimal microbial communities.
Topics: Animals; Bacteria; Biodiversity; Chronic Disease; Homeostasis; Humans; Microbiota; Paranasal Sinuses; RNA, Ribosomal, 16S; Rhinitis, Allergic; Sinusitis
PubMed: 26867525
DOI: 10.2500/ajra.2016.30.4255 -
Genes Aug 2023: Although common drugs for treating type 2 diabetes (T2D) are widely used, their therapeutic effects vary greatly. The interaction between the gut microbiome and... (Review)
Review
: Although common drugs for treating type 2 diabetes (T2D) are widely used, their therapeutic effects vary greatly. The interaction between the gut microbiome and glucose-lowering drugs is one of the main contributors to the variability in T2D progression and response to therapy. On the one hand, glucose-lowering drugs can alter gut microbiome components. On the other hand, specific gut microbiota can influence glycemic control as the therapeutic effects of these drugs. Therefore, this systematic review assesses the bi-directional relationships between common glucose-lowering drugs and gut microbiome profiles. A systematic search of Embase, Web of Science, PubMed, and Google Scholar databases was performed. Observational studies and randomised controlled trials (RCTs), published from inception to July 2023, comprising T2D patients and investigating bi-directional interactions between glucose-lowering drugs and gut microbiome, were included. Summarised findings indicated that glucose-lowering drugs could increase metabolic-healthy promoting taxa (e.g., and decrease harmful taxa (e.g., and ). Our findings also showed a significantly different abundance of gut microbiome taxa (e.g., (i.e., )) in T2D patients with poor compared to optimal glycemic control. This review provides evidence for glucose-lowering drug and gut microbiome interactions, highlighting the potential of gut microbiome modulators as co-adjuvants for T2D treatment.
Topics: Humans; Gastrointestinal Microbiome; Bacteroides; Bifidobacterium; Diabetes Mellitus, Type 2; Glucose
PubMed: 37628624
DOI: 10.3390/genes14081572