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BMC Medicine Apr 2023Considerable evidence has been reported that tobacco use could cause alterations in gut microbiota composition. The microbiota-gut-brain axis also in turn hinted at a...
BACKGROUND
Considerable evidence has been reported that tobacco use could cause alterations in gut microbiota composition. The microbiota-gut-brain axis also in turn hinted at a possible contribution of the gut microbiota to smoking. However, population-level studies with a higher evidence level for causality are lacking.
METHODS
This study utilized the summary-level data of respective genome-wide association study (GWAS) for 211 gut microbial taxa and five smoking phenotypes to reveal the causal association between the gut microbiota and tobacco smoking. Two-sample bidirectional Mendelian randomization (MR) design was deployed and comprehensively sensitive analyses were followed to validate the robustness of results. We further performed multivariable MR to evaluate the effect of neurotransmitter-associated metabolites on observed associations.
RESULTS
Our univariable MR results confirmed the effects of smoking on three taxa (Intestinimonas, Catenibacterium, and Ruminococcaceae, observed from previous studies) with boosted evidence level and identified another 13 taxa which may be causally affected by tobacco smoking. As for the other direction, we revealed that smoking behaviors could be potential consequence of specific taxa abundance. Combining with existing observational evidence, we provided novel insights regarding a positive feedback loop of smoking through Actinobacteria and indicated a potential mechanism for the link between parental smoking and early smoking initiation of their children driven by Bifidobacterium. The multivariable MR results suggested that neurotransmitter-associated metabolites (tryptophan and tyrosine, also supported by previous studies) probably played a role in the action pathway from the gut microbiota to smoking, especially for Actinobacteria and Peptococcus.
CONCLUSIONS
In summary, the current study suggested the role of the specific gut microbes on the risk for cigarette smoking (likely involving alterations in metabolites) and in turn smoking on specific gut microbes. Our findings highlighted the hazards of tobacco use for gut flora dysbiosis and shed light on the potential role of specific gut microbiota for smoking behaviors.
Topics: Gastrointestinal Microbiome; Smoking; Genome-Wide Association Study; Mendelian Randomization Analysis; Actinobacteria; Clostridiales; Tobacco Smoking; Polymorphism, Single Nucleotide
PubMed: 37118782
DOI: 10.1186/s12916-023-02863-1 -
Scientific Reports Sep 2017Individual bacteria and shifts in microbiome composition are associated with human disease, including cancer. To unravel the connections underlying oral bacterial... (Clinical Trial)
Clinical Trial
Individual bacteria and shifts in microbiome composition are associated with human disease, including cancer. To unravel the connections underlying oral bacterial dysbiosis and oral squamous cell carcinoma (OSCC), cancer lesion samples and anatomically matched normal samples were obtained from the same patients. We then profiled the bacteria within OSCC lesion surface samples at the species level using next-generation sequencing to comprehensively investigate bacterial community composition and functional genes in these samples. Significantly greater bacterial diversity was observed in the cancer samples than in the normal samples. Compared with previous studies, we identified many more taxa demonstrating remarkably different distributions between the groups. In particular, a group of periodontitis-correlated taxa, including Fusobacterium, Dialister, Peptostreptococcus, Filifactor, Peptococcus, Catonella and Parvimonas, was significantly enriched in OSCC samples. Additionally, several operational taxonomic units (OTUs) associated with Fusobacterium were highly involved in OSCC and demonstrated good diagnostic power. Our study revealed drastic changes in surface bacterial communities of OSCC. The findings enrich knowledge of the association between oral bacterial communities and oral cancer.
Topics: Bacteria; Carcinoma, Squamous Cell; Female; Humans; Male; Microbiota; Middle Aged; Mouth Neoplasms
PubMed: 28924229
DOI: 10.1038/s41598-017-11779-9 -
Journal of Cachexia, Sarcopenia and... Dec 2021Cancer cachexia is characterized by a negative energy balance, muscle and adipose tissue wasting, insulin resistance, and systemic inflammation. Because of its strong...
BACKGROUND
Cancer cachexia is characterized by a negative energy balance, muscle and adipose tissue wasting, insulin resistance, and systemic inflammation. Because of its strong negative impact on prognosis and its multifactorial nature that is still not fully understood, cachexia remains an important challenge in the field of cancer treatment. Recent animal studies indicate that the gut microbiota is involved in the pathogenesis and manifestation of cancer cachexia, but human data are lacking. The present study investigates gut microbiota composition, short-chain fatty acids (SCFA), and inflammatory parameters in human cancer cachexia.
METHODS
Faecal samples were prospectively collected in patients (N = 107) with pancreatic cancer, lung cancer, breast cancer, or ovarian cancer. Household partners (N = 76) of the patients were included as healthy controls with similar diet and environmental conditions. Patients were classified as cachectic if they lost >5% body weight in the last 6 months. Gut microbiota composition was analysed by sequencing of the 16S rRNA V4 gene region. Faecal SCFA levels were quantified by gas chromatography. Faecal calprotectin was assessed with enzyme-linked immunosorbent assay. Serum C-reactive protein and leucocyte counts were retrieved from medical records.
RESULTS
Cachexia prevalence was highest in pancreatic cancer (66.7%), followed by ovarian cancer (25%), lung cancer (20.8%), and breast cancer (17.3%). Microbial α-diversity was not significantly different between cachectic cancer patients (N = 33), non-cachectic cancer patients (N = 74), or healthy controls (N = 76) (species richness P = 0.31; Shannon effective index P = 0.46). Community structure (β-diversity) tended to differ between these groups (P = 0.053), although overall differences were subtle and no clear clustering of samples was observed. Proteobacteria (P < 0.001), an unknown genus from the Enterobacteriaceae family (P < 0.01), and Veillonella (P < 0.001) were more abundant among cachectic cancer patients. Megamonas (P < 0.05) and Peptococcus (P < 0.001) also showed differential abundance. Faecal levels of all SCFA tended to be lower in cachectic cancer patients, but only acetate concentrations were significantly reduced (P < 0.05). Faecal calprotectin levels were positively correlated with the abundance of Peptococcus, unknown Enterobacteriaceae, and Veillonella. We also identified several correlations and interactions between clinical and microbial parameters.
CONCLUSIONS
This clinical study provided the first insights into the alterations of gut microbiota composition and SCFA levels that occur in cachectic cancer patients and how they are related to inflammatory parameters. These results pave the way for further research examining the role of the gut microbiota in cancer cachexia and its potential use as therapeutic target.
Topics: Animals; Cachexia; Fatty Acids, Volatile; Gastrointestinal Microbiome; Humans; Pancreatic Neoplasms; RNA, Ribosomal, 16S
PubMed: 34609073
DOI: 10.1002/jcsm.12804 -
Frontiers in Endocrinology 2023There is some evidence for an association between gut microbiota and nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and viral hepatitis, but no...
OBJECTIVE
There is some evidence for an association between gut microbiota and nonalcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), and viral hepatitis, but no studies have explored their causal relationship.
METHODS
Instrumental variables of the gut microbiota (N = 13266) and gut microbiota-derived metabolites (N = 7824) were acquired, and a Mendelian randomization study was performed to explore their influence on NAFLD (1483 European cases and 17,781 European controls), ALD (2513 European cases and 332,951 European controls), and viral hepatitis risk (1971 European cases and 340,528 European controls). The main method for examining causality is inverse variance weighting (IVW).
RESULTS
IVW results confirmed that ( = 0.0249), ( = 0.0237), ( = 0.0245), ( = 0.0083), ( = 0.0163), and ( = 0.0472) were protective factors for NAFLD, and ( = 0.0120) was detrimental for NAFLD. The higher abundance of three genera, ( = 0.0388), ( = 0.0252), and ( = 0.0364), was correlated with a lower risk of ALD, while level was associated with a higher risk of ALD ( = 0.0371). The ( = 0.0069) and ( = 0.0195) were related to a higher risk of viral hepatitis. Besides, alanine ( = 0.0076) and phenyllactate ( = 0.0100) were found to be negatively correlated with NAFLD, while stachydrine (O = 0.0244) was found to be positively associated with NAFLD. The phenylacetate ( = 0.0353) and ursodeoxycholate ( = 0.0144) had a protective effect on ALD, while the threonate ( = 0.0370) exerted a detrimental influence on ALD. The IVW estimates of alanine ( = 0.0408) and cholate ( = 0.0293) showed their suggestive harmful effects against viral hepatitis, while threonate ( = 0.0401) displayed its suggestive protective effect against viral hepatitis.
CONCLUSION
In conclusion, our research supported causal links between the gut microbiome and its metabolites and NAFLD, ALD, and viral hepatitis.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Gastrointestinal Microbiome; Mendelian Randomization Analysis; Alanine; Clostridiales
PubMed: 37476494
DOI: 10.3389/fendo.2023.1159148 -
Iranian Journal of Microbiology Apr 2016Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of...
BACKGROUND AND OBJECTIVES
Brain abscess remains a potentially fatal central nervous system (CNS) disease, especially in developing countries. Anaerobic abscess is difficult to diagnose because of cumbersome procedures associated with the isolation of anaerobes.
MATERIALS AND METHODS
This is a hospital-based retrospective microbiological analysis of 430 brain abscess materials (purulent aspirates and/or tissue), for anaerobic organisms, that were received between 1987-2014, by the Microbiology Laboratory in our Institute.
RESULTS
Culture showed growth of bacteria 116/430 (27%) of the cases of which anaerobes were isolated in 48/116 (41.1%) of the cases. Peptostreptococcus (51.4 %), was the predominant organism isolated in four cases followed by Bacteroides and Peptococcus species.
CONCLUSION
Early diagnosis and detection of these organisms would help in the appropriate management of these patients.
PubMed: 27307977
DOI: No ID Found -
Causal effect of gut microbiota on Gastroduodenal ulcer: a two-sample Mendelian randomization study.Frontiers in Cellular and Infection... 2023Gastroduodenal ulcers are associated with infection and the use of nonsteroidal anti-inflammatory drugs (NSAIDs). However, the causal relationship between...
BACKGROUND
Gastroduodenal ulcers are associated with infection and the use of nonsteroidal anti-inflammatory drugs (NSAIDs). However, the causal relationship between gastroduodenal ulcers and gut microbiota, especially specific gut microbiota, remains unclear.
METHODS
We conducted an analysis of published data on the gut microbiota and Gastroduodenal ulcer using genome-wide association studies (GWAS). Two-sample Mendelian randomization (MR) analysis was performed to determine the causal relationship between gut microbiota and Gastroduodenal ulcer. Sensitivity, heterogeneity, and pleiotropy analyses were conducted to confirm the accuracy of the research findings.
RESULTS
Our study showed that the abundance of , , , , , and was negatively correlated with the risk of Gastroduodenal ulcer. Conversely, the abundance of , , , , , , and was positively correlated with the risk of Gastroduodenal ulcer. MR analysis revealed causal relationships between 13 bacterial genera and Gastroduodenal ulcer.
CONCLUSION
This study represents a groundbreaking endeavor by furnishing preliminary evidence regarding the potentially advantageous or detrimental causal link between the gut microbiota and Gastroduodenal ulcer, employing Mendelian Randomization (MR) analysis for the first time. These discoveries have the potential to yield fresh perspectives on the prevention and therapeutic approaches concerning Gastroduodenal ulcer, with a specific focus on the modulation of the gut microbiota.
Topics: Humans; Gastrointestinal Microbiome; Genome-Wide Association Study; Helicobacter Infections; Mendelian Randomization Analysis; Helicobacter pylori; Peptic Ulcer; Clostridiaceae; Clostridiales
PubMed: 38156322
DOI: 10.3389/fcimb.2023.1322537 -
Molecules (Basel, Switzerland) May 2022The aim of this study was to investigate the effects of quercetin on inflammatory response and intestinal microflora in broiler chicken jejuna. A total of 120 broiler...
The aim of this study was to investigate the effects of quercetin on inflammatory response and intestinal microflora in broiler chicken jejuna. A total of 120 broiler chickens were allocated into 3 groups: saline-challenged broilers fed a basal diet (CTR group), lipopolysaccharide (LPS)-challenged broilers fed a basal diet (L group) and LPS-challenged broilers fed a basal diet supplemented with 200 mg/kg quercetin (LQ group). Our results showed that LPS significantly increased expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, interferon (IFN)-γ, toll-like receptor (TLR)-4, and diamine oxidase activity (DAO), and decreased expression of zona occludens-1 ZO-1, Occludin and Bcl-2 in the jejunum, while dietary quercetin prevented the adverse effects of LPS injection. LPS injection significantly decreased the number of , and at the phylum level when compared to the CTR group. Additionally, at genus level, compared with the CTR group, the abundance of , , , , , and in L group was significantly decreased, while dietary quercetin restored the numbers of these bacteria. In conclusion, our results demonstrated that dietary quercetin could alleviate inflammatory responses of broiler chickens accompanied by modulating jejunum microflora.
Topics: Animal Feed; Animals; Chickens; Gastrointestinal Microbiome; Inflammation; Lipopolysaccharides; Quercetin
PubMed: 35630745
DOI: 10.3390/molecules27103269 -
Revista Espanola de Quimioterapia :... Sep 2019Ceftobiprole, a novel last generation parenteral cephalosporin, has an extended spectrum of activity, notably against methicillin-resistant Staphylococcus aureus (MRSA),... (Review)
Review
Ceftobiprole, a novel last generation parenteral cephalosporin, has an extended spectrum of activity, notably against methicillin-resistant Staphylococcus aureus (MRSA), ampicillin-susceptible enterococci, penicillin-resistant pneumococci, Enterobacterales and susceptible Pseudomonas aeruginosa. It exerts an inhibitory action on essential peptidoglycan transpeptidases, interfering with cell wall synthesis. The inhibitory action of ceftobiprole through binding to abnormal PBPs like PBP2a in methicillin-resistant staphylococci and PBP2b and PBP2x in the case of β-lactam-resistant pneumococci, ultimately leads to rapid bacterial cell death. In the case of Enterobacterales, ceftobiprole retains activity against narrow spectrum β-lactamases but is hydrolysed by their extended-spectrum counterparts, overexpressed Amp C, and carbapenemases. It is also affected by certain efflux pumps from P. aeruginosa. For anaerobic bacteria, ceftobiprole is active against Gram-positive Clostridioides difficile and Peptococcus spp. and Gram-negative Fusobacterium nucleatum but not against Bacteroides group or other anaerobic Gram-negatives. In in vitro studies, a low propensity to select for resistant subpopulations has been demonstrated. Currently, ceftobiprole is approved for the treatment of community-acquired pneumonia and hospital-acquired pneumonia with the exception of ventilator-associated pneumonia. Ceftobiprole's place in therapy appears to lie mainly in its combined activity against Gram-positive organisms, such as S. aureus and S. pneumoniae alongside that against Gram-negative organisms such as P. aeruginosa.
Topics: Aminoacyltransferases; Anti-Bacterial Agents; Cephalosporins; Community-Acquired Infections; Endopeptidases; Enterobacteriaceae; Enterococcus; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Methicillin-Resistant Staphylococcus aureus; Penicillin Resistance; Penicillin-Binding Proteins; Pneumonia, Ventilator-Associated; Pseudomonas aeruginosa; Streptococcus pneumoniae; beta-Lactamase Inhibitors
PubMed: 31364335
DOI: No ID Found -
Metabolites Aug 2022The prevalence of gestational diabetes mellitus (GDM) is a global public health concern. The mechanism that leads to glucose tolerance beyond normal physiological levels...
The prevalence of gestational diabetes mellitus (GDM) is a global public health concern. The mechanism that leads to glucose tolerance beyond normal physiological levels to pathogenic conditions remains incompletely understood, and it is speculated that the maternal microbiome may play an important role. This study analyzes the gut microbiota composition in each trimester of weight-matched women with and without GDM and examines possible bacterial genera associations with GDM. This study followed 56 pregnant women with GDM and 59 without admitted to the outpatient clinic during their first/second or third trimester of gestation. They were submitted to a standardized questionnaire, dietary recalls, clinical examination, biological sample collection, and molecular profiling of fecal microbiota. Women with GDM were older and had a higher number of pregnancies than normal-tolerant ones. There was no difference in alpha diversity, and the groups did not differ regarding the overall microbiota structure. A higher abundance of in the GDM group was found. A positive correlation between and abundances with one-hour post-challenge plasma glucose and a negative correlation between and two-hour plasma glucose levels were observed. and abundances were increased in the third gestational trimester for both groups. The gut microbiota composition was not dependent on the presence of GDM weight-matched women throughout gestation. However, some genera abundances showed associations with glucose metabolism. Our findings may therefore encourage a deeper understanding of physiological and pathophysiological changes in the microbiota throughout pregnancy, which could have further implications for diseases prevention.
PubMed: 36144203
DOI: 10.3390/metabo12090796 -
International Journal of Molecular... Aug 2022Rheumatoid arthritis (RA) and periodontitis are suggested to be closely linked based on microbial dysbiosis, but limited subgingival bacteria have been proven in the...
Rheumatoid arthritis (RA) and periodontitis are suggested to be closely linked based on microbial dysbiosis, but limited subgingival bacteria have been proven in the pathogenesis of RA. We enrolled 30 RA patients and 25 controls and divided them into three groups with matched age, gender, and diabetes statuses: group AM (all of the matched participants), group PD (periodontally diseased), and group PH (periodontally healthy). Their subgingival microbial composition was determined by V3-V4 16S rRNA gene sequencing. Significant differences in subgingival microbial clustering between the RA patients and controls were observed in groups AM and PD. Among the taxa enriched in RA, and were the only two species displaying positive correlation to the level of anti-citrullinated protein antibodies (ACPAs) in both of the groups. Surprisingly, the median of relative abundances of and were 0% in the controls of group PD. Furthermore, a gene encoding arginine deiminase with the capability to produce citrulline was addressed in the complete genome sequence of . This is the first study to elucidate the important roles of and as periodontal bacteria leading to RA possibly through the induction of ACPA production.
Topics: Anti-Citrullinated Protein Antibodies; Arthritis, Rheumatoid; Autoantibodies; Bacteria; Humans; Microbiota; Periodontitis; RNA, Ribosomal, 16S
PubMed: 36077282
DOI: 10.3390/ijms23179883