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1.
J Gastroenterol Hepatol ; 37(2): 342-351, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34888949

RESUMO

BACKGROUND AND AIM: Inflammatory bowel diseases (IBD) are chronic gastrointestinal inflammatory conditions comprising two major subtypes: Crohn's disease (CD) and ulcerative colitis (UC). The incidence of IBD is increasing in Asian countries including Malaysia. The aim of this study was to determine whether 32 single nucleotide polymorphisms (SNPs) strongly associated with IBD from genome-wide association studies, performed mainly in Caucasian populations, are associated with IBD in a Malaysian population, correlating these findings with local and systemic inflammation. METHODS: Selected SNPs were investigated in a Malaysian cohort comprising 36 IBD patients and 75 controls using customized matrix-assisted laser desorption ionization time-of-flight genotyping. Local mRNA and/or systemic protein levels of IL-10, IL-12, IL-22, IL-23, and TNF-α were measured in these same subjects. RESULTS: ATG16L2 rs11235667 and LINC00824 rs6651252 was significantly associated with increased CD risk while IL12B rs56167332 was a significant protective factor. Three SNPs (SBNO2 rs2024092, CARD9 rs10781499, and rs17085007 between GPR12-USP12) were significantly associated with increased UC risk while NKX2-3 rs4409764 was a significant protective factor. After adjusting for age, gender, and ethnicity, SBNO2 rs2024092, ATG16L2 rs11235667, CARD9 rs10781499, and LINC00824 rs6651252 remained associated with IBD. Interestingly, the risk alleles of IL10 rs3024505, CARD9 rs1078149, and IL12 rs6556412 were associated with higher levels of IL-10, IL-22, and IL-23 in these same subjects, respectively. CONCLUSIONS: This study identified eight SNPs associated with IBD and/or its subtypes in the Malaysia population, significantly advancing our understanding of the genetic contribution to IBD in this understudied population. Three of these SNPs modulated relevant cytokine levels and thus, may directly contribute to IBD pathogenesis.


Assuntos
Predisposição Genética para Doença , Imunidade Inata , Doenças Inflamatórias Intestinais , Estudo de Associação Genômica Ampla , Humanos , Imunidade Inata/genética , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/genética , Malásia/epidemiologia , Polimorfismo de Nucleotídeo Único , Risco
2.
Sci Rep ; 10(1): 12932, 2020 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-32737354

RESUMO

Epithelial barrier injury allows contaminants to cross-over into the blood stream and trigger an inflammatory response, contributing to inflammatory bowel disease (IBD). Currently there is no single test that can reliably diagnose intestinal mucosal barrier function or measure impaired epithelial cell integrity associated with increasing permeability. Here, we assess the association between serum proteins and small intestinal permeability as detected by confocal laser endomicroscopy (CLE); in particular the known IBD marker-secreted phosphoprotein 24 (SPP24) and its binding partners; and use developed monoclonal antibodies to assess the role of SPP24 in mucosal healing. Sera were obtained from 28 IBD patients and non-IBD controls undergoing CLE with scores ranging from low to high permeability, as well as active ulcerative colitis from 53 patients undergoing fecal microbiota transplant therapy (FMT). Higher permeability associated with altered lipid metabolism, heightened innate immune response and junctional protein signalling in UC patients. A correlation between increasing leak and SPP24 peptide was observed. There is a strong indication of the novel role of SPP24 in gut barrier dysfunction particularly in ulcerative colitis. Its correlation to the established CLE for monitoring permeability has the potential to provide a blood based parallel to monitor and guide therapy more readily across a broad spectrum of illnesses for which 'leak' dominates the pathology.


Assuntos
Colite Ulcerativa/sangue , Endocitose , Mucosa Intestinal/metabolismo , Metabolismo dos Lipídeos , Fosfoproteínas/sangue , Transdução de Sinais , Adolescente , Adulto , Idoso , Biomarcadores , Colite Ulcerativa/patologia , Colite Ulcerativa/terapia , Transplante de Microbiota Fecal , Feminino , Humanos , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade
3.
Cell Host Microbe ; 27(5): 823-829.e3, 2020 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-32298656

RESUMO

Fecal microbiota transplantation (FMT) targeting gut microbiota has recently been successfully applied to ulcerative colitis. However, only a subset of patients responds to FMT, and there is a pressing need for biomarkers of responsiveness. Fungi (the mycobiota) represent a highly immunologically reactive component of the gut microbiota. We analyzed samples from a large randomized controlled trial of FMT for ulcerative colitis (UC). High Candida abundance pre-FMT was associated with a clinical response, whereas decreased Candida abundance post-FMT was indicative of ameliorated disease severity. High pre-FMT Candida was associated with increased bacterial diversity post-FMT, and the presence of genera was linked to FMT responsiveness. Although we detected elevated anti-Candida antibodies in placebo recipients, this increase was abrogated in FMT recipients. Our data suggest that FMT might reduce Candida to contain pro-inflammatory immunity during intestinal disease and highlight the utility of mycobiota-focused approaches to identify FMT responders prior to therapy initiation.


Assuntos
Colite Ulcerativa/terapia , Transplante de Microbiota Fecal/métodos , Fezes/microbiologia , Fungos , Adulto , Anticorpos Antifúngicos/sangue , Bactérias/genética , Candida , Colite Ulcerativa/microbiologia , Feminino , Fungos/genética , Microbioma Gastrointestinal/fisiologia , Humanos , Masculino , RNA Ribossômico 16S/genética , Resultado do Tratamento
4.
Biochim Biophys Acta Rev Cancer ; 1872(2): 188309, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31394110

RESUMO

While Helicobacter pylori is a fundamental risk factor, gastric cancer (GC) aetiology involves combined effects of microbial (both H. pylori and non-H. pylori), host and environmental factors. Significant differences exist between the gastric microbiome of those with gastritis, intestinal metaplasia and GC, suggesting that dysbiosis in the stomach is dynamic and correlates with progression to GC. Most notably, a consistent increase in abundance of lactic acid bacteria (LAB) has been observed in GC patients including Streptococcus, Lactobacillus, Bifidobacterium and Lactococcus. This review summarises how LAB can influence GC by a number of mechanisms that include supply of exogenous lactate -a fuel source for cancer cells that promotes inflammation, angiogenesis, metastasis, epithelial-mesenchymal transition and immune evasion-, production of reactive oxygen species and N-nitroso compounds, as well as anti-H. pylori properties that enable colonization by other non-H. pylori carcinogenic pathobionts.


Assuntos
Disbiose/metabolismo , Lactobacillales/patogenicidade , Neoplasias Gástricas/microbiologia , Progressão da Doença , Disbiose/complicações , Transição Epitelial-Mesenquimal , Humanos , Espécies Reativas de Oxigênio/metabolismo , Neoplasias Gástricas/metabolismo , Evasão Tumoral , Microambiente Tumoral
5.
Gastroenterology ; 156(5): 1440-1454.e2, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30529583

RESUMO

BACKGROUND & AIMS: Fecal microbiota transplantation (FMT) can induce remission in patients with ulcerative colitis (UC). In a randomized controlled trial of FMT in patients with active UC, we aimed to identify bacterial taxonomic and functional factors associated with response to therapy. METHODS: We performed a double-blind trial of 81 patients with active UC randomly assigned to groups that received an initial colonoscopic infusion and then intensive multidonor FMT or placebo enemas, 5 d/wk for 8 weeks. Patients in the FMT group received blended homogenized stool from 3-7 unrelated donors. Patients in the placebo group were eligible to receive open-label FMT after the double-blind study period. We collected 314 fecal samples from the patients at screening, every 4 weeks during treatment, and 8 weeks after the blinded or open-label FMT therapy. We also collected 160 large-bowel biopsy samples from the patients at study entry, at completion of 8 weeks of blinded therapy, and at the end of open-label FMT, if applicable. We analyzed 105 fecal samples from the 14 individual donors (n = 55), who in turn contributed to 21 multidonor batches (n = 50). Bacteria in colonic and fecal samples were analyzed by both 16S ribosomal RNA gene and transcript amplicon sequencing; 285 fecal samples were analyzed by shotgun metagenomics, and 60 fecal samples were analyzed for metabolome features. RESULTS: FMT increased microbial diversity and altered composition, based on analyses of colon and fecal samples collected before vs after FMT. Diversity was greater in fecal and colon samples collected before and after FMT treatment from patients who achieved remission compared with patients who did not. Patients in remission after FMT had enrichment of Eubacterium hallii and Roseburia inulivorans compared with patients who did not achieve remission after FMT and had increased levels of short-chain fatty acid biosynthesis and secondary bile acids. Patients who did not achieve remission had enrichment of Fusobacterium gonidiaformans, Sutterella wadsworthensis, and Escherichia species and increased levels of heme and lipopolysaccharide biosynthesis. Bacteroides in donor stool were associated with remission in patients receiving FMT, and Streptococcus species in donor stool was associated with no response to FMT. CONCLUSIONS: In an analysis of fecal and colonic mucosa samples from patients receiving FMT for active UC and stool samples from donors, we associated specific bacteria and metabolic pathways with induction of remission. These findings may be of value in the design of microbe-based therapies for UC. ClinicalTrials.gov, Number NCT01896635.


Assuntos
Bactérias/metabolismo , Colite Ulcerativa/terapia , Microbioma Gastrointestinal , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Biomarcadores/metabolismo , Colite Ulcerativa/diagnóstico , Colite Ulcerativa/microbiologia , Método Duplo-Cego , Transplante de Microbiota Fecal/efeitos adversos , Fezes/microbiologia , Humanos , Metabolômica , New South Wales , Indução de Remissão , Ribotipagem , Fatores de Tempo , Resultado do Tratamento
6.
Int J Microbiol ; 2018: 9203908, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30123276

RESUMO

Crohn's disease (CD) is an inflammatory disease of the gastrointestinal tract, with a rising incidence worldwide, particularly in children. CD is thought to arise due to an immune response to environmental factors. The role of bacteria in CD has recently been highlighted, and here, we examine the prevalence of two bacterial species, enterotoxigenic Bacteroides fragilis (ETBF) and Fusobacterium nucleatum, implicated in gastrointestinal pathologies, in a pediatric CD cohort. Stool samples from 30 children with treatment-naïve CD and 30 age- and sex-matched controls were collected, and DNA was extracted. Quantitative PCR was used to determine the levels of ETBF and F. nucleatum in stool samples. Bacterial positivity and relative abundance were assessed between cases and controls and in relation to disease severity. No associations were found between colonization with ETBF and CD, or between colonization with either ETBF or F. nucleatum and disease severity or presence of C. concisus. However, a strong association was observed between positivity for F. nucleatum in the stool samples and the occurrence of CD in patients (25/30) as compared to controls (8/30) (P=0.003). F. nucleatum is more prevalent in the stool samples of pediatric CD patients, compared to healthy controls, and may have potential use as a biomarker of pediatric CD.

7.
Infect Immun ; 86(7)2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29685983

RESUMO

The morbidity and mortality resulting from acute gastroenteritis and associated chronic sequelae represent a substantial burden on health care systems worldwide. Few studies have investigated changes in the gut microbiome following an episode of acute gastroenteritis. By using nondirected 16S rRNA gene amplicon sequencing, the fecal microbiota of 475 patients with acute gastroenteritis was examined. Patient age was correlated with the overall microbial composition, with a decrease in the abundance of Faecalibacterium being observed in older patients. We observed the emergence of a potential Escherichia-Shigella-dominated enterotype in a subset of patients, and this enterotype was predicted to be more proinflammatory than the other common enterotypes, with the latter being dominated by Bacteroides or Faecalibacterium The increased abundance of Escherichia-Shigella did not appear to be associated with infection with an agent of a similar sequence similarity. Stool color and consistency were associated with the diversity and composition of the microbiome, with deviations from the norm (not brown and solid) showing increases in the abundances of bacteria such as Escherichia-Shigella and Veillonella Analysis of enriched outliers within the data identified a range of genera previously associated with gastrointestinal diseases, including Treponema, Proteus, Capnocytophaga, Arcobacter, Campylobacter, Haemophilus, Aeromonas, and Pseudomonas Our data represent the first in-depth analysis of gut microbiota in acute gastroenteritis. Phenotypic changes in stool color and consistency were associated with specific changes in the microbiota. Enriched bacterial taxa were detected in cases where no causative agent was identified by using routine diagnostic tests, suggesting that in the future, microbiome analyses may be utilized to improve diagnostics.


Assuntos
Bactérias/isolamento & purificação , Gastroenterite/etiologia , Microbioma Gastrointestinal , Doença Aguda , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Bactérias/classificação , Criança , Pré-Escolar , Fezes , Gastroenterite/microbiologia , Humanos , Lactente , Pessoa de Meia-Idade , Adulto Jovem
8.
Sci Rep ; 7(1): 15957, 2017 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-29162924

RESUMO

The gastric microbiome has been proposed as an etiological factor in gastric carcinogenesis. We compared the gastric microbiota in subjects presenting with gastric cancer (GC, n = 12) and controls (functional dyspepsia (FD), n = 20) from a high GC risk population in Singapore and Malaysia. cDNA from 16S rRNA transcripts were amplified (515F-806R) and sequenced using Illumina MiSeq 2 × 250 bp chemistry. Increased richness and phylogenetic diversity but not Shannon's diversity was found in GC as compared to controls. nMDS clustered GC and FD subjects separately, with PERMANOVA confirming a significant difference between the groups. H. pylori serological status had a significant impact on gastric microbiome α-diversity and composition. Several bacterial taxa were enriched in GC, including Lactococcus, Veilonella, and Fusobacteriaceae (Fusobacterium and Leptotrichia). Prediction of bacterial metabolic contribution indicated that serological status had a significant impact on metabolic function, while carbohydrate digestion and pathways were enriched in GC. Our findings highlight three mechanisms of interest in GC, including enrichment of pro-inflammatory oral bacterial species, increased abundance of lactic acid producing bacteria, and enrichment of short chain fatty acid production pathways.


Assuntos
Carcinogênese/patologia , Disbiose/microbiologia , Microbioma Gastrointestinal , Neoplasias Gástricas/microbiologia , Biodiversidade , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori/fisiologia , Humanos , Filogenia
9.
J Crohns Colitis ; 11(10): 1180-1199, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28486648

RESUMO

BACKGROUND: Faecal microbiota transplantation [FMT] has been investigated as a potential treatment for inflammatory bowel disease [IBD]. We thus performed a systematic review and meta-analysis assessing the effectiveness and safety of FMT in IBD. METHODS: A systematic review was conducted until January 2017. Studies were excluded if patients had co-infection or data were pooled across disease subtypes (ulcerative colitis [UC], Crohn's disease [CD], pouchitis). Clinical remission was established as the primary outcome. Pooled effect sizes and 95% confidence intervals were obtained using the random effects model. RESULTS: In all, 53 studies were included [41 in UC, 11 in CD, 4 in pouchitis]. Overall, 36% [201/555] of UC, 50.5% [42/83] of CD, and 21.5% [5/23] of pouchitis patients achieved clinical remission. Among cohort studies, the pooled proportion achieving clinical remission was 33% (95% confidence interval [CI] = 23%-43%] for UC and 52% [95% CI = 31%-72%] for CD, both with moderate risk of heterogeneity. For four RCTs in UC, significant benefit in clinical remission (pooled odds ratios [[P-OR] = 2.89, 95% CI = 1.36-6.13, p = 0.006) with moderate heterogeneity [Cochran's Q, p = 0.188; I2 = 37%] was noted. Sub-analyses suggest remission in UC improved with increased number of FMT infusions and lower gastrointestinal tract administration. Most adverse events were transient gastrointestinal complaints. Microbiota analysis was performed in 24 studies, with many identifying increased diversity and a shift in recipient microbiota profile towards the donor post-FMT. CONCLUSIONS: FMT appears effective in UC remission induction, but long-term durability and safety remain unclear. Additional well-designed controlled studies of FMT in IBD are needed, especially in CD and pouchitis.


Assuntos
Transplante de Microbiota Fecal , Doenças Inflamatórias Intestinais/terapia , Colite Ulcerativa/terapia , Doença de Crohn/terapia , Microbioma Gastrointestinal , Humanos , Resultado do Tratamento
10.
Lancet ; 389(10075): 1218-1228, 2017 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-28214091

RESUMO

BACKGROUND: The intestinal microbiota is implicated in the pathogenesis of ulcerative colitis. Faecal microbiota transplantation is a novel form of therapeutic microbial manipulation, but its efficacy in ulcerative colitis is uncertain. We aimed to establish the efficacy of intensive-dosing, multidonor, faecal microbiota transplantation in active ulcerative colitis. METHODS: We conducted a multicentre, double-blind, randomised, placebo-controlled trial at three hospitals in Australia. We randomly allocated patients with active ulcerative colitis (Mayo score 4-10) in a 1:1 ratio, using a pre-established randomisation list, to either faecal microbiota transplantation or placebo colonoscopic infusion, followed by enemas 5 days per week for 8 weeks. Patients, treating clinicians, and other study staff were unaware of the assigned treatment. Faecal microbiota transplantation enemas were each derived from between three and seven unrelated donors. The primary outcome was steroid-free clinical remission with endoscopic remission or response (Mayo score ≤2, all subscores ≤1, and ≥1 point reduction in endoscopy subscore) at week 8. Analysis was by modified intention-to-treat and included all patients receiving one study dose. We performed 16S rRNA stool analysis to assess associated microbial changes. This trial is registered with ClinicalTrials.gov, number NCT01896635. The trial has ended; this report presents the final analysis. FINDINGS: From November, 2013, to May, 2015, 85 patients were enrolled to our trial, of whom 42 were randomly assigned faecal microbiota transplantation and 43 were allocated placebo. One patient assigned faecal microbiota transplantation and three allocated placebo did not receive study treatment and were excluded from the analysis. The primary outcome was achieved in 11 (27%) of 41 patients allocated faecal microbiota transplantation versus three (8%) of 40 who were assigned placebo (risk ratio 3·6, 95% CI 1·1-11·9; p=0·021). Adverse events were reported by 32 (78%) of 41 patients allocated faecal microbiota transplantation and 33 (83%) of 40 who were assigned placebo; most were self-limiting gastrointestinal complaints, with no significant difference in number or type of adverse events between treatment groups. Serious adverse events occurred in two patients assigned faecal microbiota transplantation and in one allocated placebo. Microbial diversity increased with and persisted after faecal microbiota transplantation. Several bacterial taxa were associated with clinical outcome; in particular, the presence of Fusobacterium spp was associated with lack of remission. INTERPRETATION: Intensive-dosing, multidonor, faecal microbiota transplantation induces clinical remission and endoscopic improvement in active ulcerative colitis and is associated with distinct microbial changes that relate to outcome. Faecal microbiota transplantation is, thus, a promising new therapeutic option for ulcerative colitis. Future work should focus on precisely defining the optimum treatment intensity and the role of donor-recipient matching based on microbial profiles. FUNDING: Broad Medical Research Program, Gastroenterological Society of Australia, Mount Sinai (New York) SUCCESS fund, University of New South Wales.


Assuntos
Colite Ulcerativa/terapia , Transplante de Microbiota Fecal/métodos , Adulto , Colite Ulcerativa/microbiologia , Colonoscopia , Método Duplo-Cego , Transplante de Microbiota Fecal/efeitos adversos , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal , Humanos , Masculino , Pessoa de Meia-Idade , Indução de Remissão , Índice de Gravidade de Doença , Doadores de Tecidos
11.
Gut ; 66(2): 235-249, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-26508508

RESUMO

OBJECTIVE: To conduct a comprehensive global systematic review and meta-analysis on the association between Helicobacter pylori infection and IBD. As bacterial antigen cross-reactivity has been postulated to be involved in this association, published data on enterohepatic Helicobacter spp (EHS) and Campylobacter spp and IBD was also analysed. DESIGN: Electronic databases were searched up to July 2015 for all case-control studies on H. pylori infection/EHS/Campylobacter spp and IBD. Pooled ORs (P-OR) and 95% CIs were obtained using the random effects model. Heterogeneity, sensitivity and stratified analyses were performed. RESULTS: Analyses comprising patients with Crohn's disease (CD), UC and IBD unclassified (IBDU), showed a consistent negative association between gastric H. pylori infection and IBD (P-OR: 0.43, p value <1e-10). This association appears to be stronger in patients with CD (P-OR: 0.38, p value <1e-10) and IBDU (P-OR: 0.43, p value=0.008) than UC (P-OR: 0.53, p value <1e-10). Stratification by age, ethnicity and medications showed significant results. In contrast to gastric H. pylori, non H. pylori-EHS (P-OR: 2.62, p value=0.001) and Campylobacter spp, in particular C. concisus (P-OR: 3.76, p value=0.006) and C. showae (P-OR: 2.39, p value=0.027), increase IBD risk. CONCLUSIONS: H. pylori infection is negatively associated with IBD regardless of ethnicity, age, H. pylori detection methods and previous use of aminosalicylates and corticosteroids. Antibiotics influenced the magnitude of this association. Closely related bacteria including EHS and Campylobacter spp increase the risk of IBD. These results infer that H. pylori might exert an immunomodulatory effect in IBD.


Assuntos
Infecções por Campylobacter/epidemiologia , Campylobacter , Colite Ulcerativa/epidemiologia , Doença de Crohn/epidemiologia , Infecções por Helicobacter/epidemiologia , Helicobacter pylori , Antibacterianos/uso terapêutico , Infecções por Campylobacter/complicações , Infecções por Helicobacter/complicações , Humanos , Fatores de Proteção , Fatores de Risco , Gastropatias/epidemiologia , Gastropatias/microbiologia
12.
Mol Nutr Food Res ; 61(1)2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-26767716

RESUMO

SCOPE: Overconsumption of energy-rich food is a major contributor to the obesity epidemic. The eating habits of many people are characterized by the cycling between overconsumption of energy-rich foods and dieting, the effects of which on the microbiota are currently unknown. METHODS AND RESULTS: We compared the fecal microbiota of rats either continuously fed chow or palatable cafeteria diet to a "cycled" group switched between the two diets (chow for 4, cafeteria for 3 days/wk, n = 12/group) over 16 wk. Enriched bacterial metabolic pathways were predicted, and a range of metabolic parameters was correlated to microbial taxa and pathways. Cycled rats showed large excursions in food intake on each diet switch. When switched from chow to cafeteria, they overconsumed, and when switched back to chow they underconsumed relative to those maintained on the two diets. Metabolic parameters of cycled rats were intermediate between those of the other diet groups (p < 0.05). The microbiota of cycled rats was nearly indistinguishable from rats under constant cafeteria diet, and both groups were significantly different to the chow group. Correlation analyses identified microbial metabolic pathways associated with an obese phenotype. CONCLUSION: These data suggest that continuous or intermittent exposure to palatable foods have similar effects on the gut microbiota.


Assuntos
Dieta , Microbioma Gastrointestinal , Obesidade/microbiologia , Tecido Adiposo , Animais , Dieta Ocidental , Ingestão de Alimentos , Comportamento Alimentar , Microbioma Gastrointestinal/genética , Insulina/sangue , Leptina/sangue , Masculino , Metagenômica/métodos , Obesidade/etiologia , Ratos Sprague-Dawley
13.
Best Pract Res Clin Gastroenterol ; 31(6): 657-668, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29566909

RESUMO

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease worldwide. It is well-accepted that gut dysbiosis is associated with NAFLD, however, there is some conflicting evidence regarding the nature of these alterations. Infection with Helicobacter species, mainly H. pylori, has also been associated with increased NAFLD risk, however, some studies have failed to reproduce this finding. Further studies including large study samples and standardised procedures for microbiota analyses, H. pylori detection and NAFLD diagnostic criteria, are required. The mechanisms involving Helicobacter species and the intestinal microbiome in NAFLD pathogenesis appear to be part of the multiple-hit theory, in which increased intestinal permeability, inflammatory responses, altered choline, bile acids and carbohydrate metabolism, production of short-chain fatty acids, urea cycle and urea transport systems, altered maintenance of hepatic γδT-17 cells, insulin resistance, hormones secreted by the adipose tissue, metabolic hormones, bacterial metabolites and Helicobacter toxins, are all implicated.


Assuntos
Microbioma Gastrointestinal/imunologia , Helicobacter pylori/patogenicidade , Hepatopatia Gordurosa não Alcoólica/etiologia , Helicobacter pylori/crescimento & desenvolvimento , Humanos , Hepatopatia Gordurosa não Alcoólica/microbiologia , Hepatopatia Gordurosa não Alcoólica/patologia
14.
Sci Rep ; 6: 34288, 2016 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-27677841

RESUMO

The epithelial response to the opportunistic pathogen Campylobacter concisus is poorly characterised. Here, we assessed the intestinal epithelial responses to two C. concisus strains with different virulence characteristics in Caco-2 cells using RNAseq, and validated a subset of the response using qPCR arrays. C. concisus strains induced distinct response patterns from intestinal epithelial cells, with the toxigenic strain inducing a significantly more amplified response. A range of cellular functions were significantly regulated in a strain-specific manner, including epithelial-to-mesenchymal transition (NOTCH and Hedgehog), cytoskeletal remodeling, tight junctions, inflammatory responses and autophagy. Pattern recognition receptors were regulated, including TLR3 and IFI16, suggesting that nucleic acid sensing was important for epithelial recognition of C. concisus. C. concisus zonula occludens toxin (ZOT) was expressed and purified, and the epithelial response to the toxin was analysed using RNAseq. ZOT upregulated PAR2 expression, as well as processes related to tight junctions and cytoskeletal remodeling. C. concisus ZOT also induced upregulation of TLR3, pro-inflammatory cytokines IL6, IL8 and chemokine CXCL16, as well as the executioner caspase CASP7. Here, we characterise distinct global epithelial responses to C. concisus strains, and the virulence factor ZOT, and provide novel information on mechanisms by which this bacterium may affect the host.

16.
Microbiology (Reading) ; 162(8): 1388-1397, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27339421

RESUMO

Campylobacter concisus is a member of the oral microbiota that has been associated with the development of inflammatory bowel diseases. However, the role of the bacterium in disease aetiology remains poorly understood. Here, we examine optimal conditions for the growth of C. concisus, and the pathogenic potential of this bacterium in human gastrointestinal cells from the upper tract. Further, the presence of C. concisus in the lower tract of Crohn's disease (CD) patients undergoing therapy is observed, and the associations of C. concisus with the abundance of other microbial taxa and compounds they produce are evaluated. C. concisus strains had the ability to tolerate moderate levels of acidity, adhere to and invade esophageal and gastric cells; however, these properties did not correlate with their pathogenic potential in intestinal cells. The presence of the bacterium in the lower gut of CD patients was associated with an increased relative abundance of Faecalibacterium and Lachnospiraceae incertae sedis. Short chain fatty acids that can be produced by these microbial species did not appear to be responsible for this association. However, we identified genetic similarity between C. concisus and Firmicutes, specifically within aspartate and glutamate racemases. The potential pathogenesis of C. concisus in the upper gastrointestinal tract, and the responsiveness of the bacterium to therapy in a subset of CD patients warrant further investigation into whether this bacterium has a causal role in disease or its presence is incidental.


Assuntos
Sangue/microbiologia , Campylobacter/classificação , Campylobacter/patogenicidade , Doença de Crohn/microbiologia , Ácidos Graxos Voláteis/metabolismo , Firmicutes/classificação , Trato Gastrointestinal/microbiologia , Aderência Bacteriana/fisiologia , Campylobacter/genética , Campylobacter/metabolismo , Infecções por Campylobacter/microbiologia , Células Cultivadas , Clostridiales/isolamento & purificação , Faecalibacterium/isolamento & purificação , Firmicutes/genética , Trato Gastrointestinal/citologia , Humanos
17.
PLoS One ; 11(2): e0148731, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26849125

RESUMO

The association of Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) with Crohn's disease is a controversial issue. M. paratuberculosis is detected by amplifying the IS900 gene, as microbial culture is unreliable from humans. We determined the presence of M. paratuberculosis in patients with Crohn's disease (CD) (n = 22), ulcerative colitis (UC) (n = 20), aphthous ulcers (n = 21) and controls (n = 42) using PCR assays validated on bovine tissue. Culture from human tissue was also performed. M. paratuberculosis prevalence in the CD and UC groups was compared to the prevalence in age and sex matched non-inflammatory bowel disease controls. Patients and controls were determined to be M. paratuberculosis positive if all three PCR assays were positive. A significant association was found between M. paratuberculosis and Crohn's disease (p = 0.02) that was not related to age, gender, place of birth, smoking or alcohol intake. No significant association was detected between M. paratuberculosis and UC or aphthous ulcers; however, one M. paratuberculosis isolate was successfully cultured from a patient with UC. We report the resistance of this isolate to ethambutol, rifampin, clofazamine and streptomycin. Interestingly this isolate could not only survive but could grow slowly at 5°C. We demonstrate a significant association between M. paratuberculosis and CD using multiple pre-validated PCR assays and that M. paratuberculosis can be isolated from patients with UC.


Assuntos
Colite Ulcerativa/microbiologia , Doença de Crohn/microbiologia , Farmacorresistência Bacteriana , Mycobacterium avium subsp. paratuberculosis , Paratuberculose/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bovinos , Colite Ulcerativa/genética , Doença de Crohn/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mycobacterium avium subsp. paratuberculosis/genética , Mycobacterium avium subsp. paratuberculosis/crescimento & desenvolvimento , Mycobacterium avium subsp. paratuberculosis/isolamento & purificação , Paratuberculose/genética
18.
Diagn Microbiol Infect Dis ; 84(2): 151-4, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26643061

RESUMO

Limited information is available on the systemic immunoglobulin response in patients infected with the emerging pathogen Campylobacter concisus. The aim of the present study was to detect anti-C. concisus antibodies in serum of 88 patients with C. concisus gastroenteritis. Specific IgG antibodies to C. concisus were measured in serum using an in-house enzyme-linked immunosorbent assay, and pooled donor serum was used as a control. The mean optical density was 0.135 (SEM: 0.020) for the 88 adult patients and 0.100 (SEM: 0.011) in controls. When using an optical density value equal to the mean +3 SEM for the control serum, 22 (25%) C. concisus-positive patients had increased IgG antibodies. Patients with high IgG levels more often reported headache, and they had a trend toward more mucus in stools, whereas IgG levels were unrelated to age, duration of diarrhea, number of stools per day, and weight loss.


Assuntos
Anticorpos Antibacterianos/sangue , Infecções por Campylobacter/imunologia , Infecções por Campylobacter/microbiologia , Campylobacter/imunologia , Diarreia/imunologia , Diarreia/microbiologia , Imunoglobulina G/sangue , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Infecções por Campylobacter/patologia , Diarreia/patologia , Ensaio de Imunoadsorção Enzimática , Feminino , Cefaleia/etiologia , Humanos , Pessoa de Meia-Idade , Adulto Jovem
19.
J Med Microbiol ; 65(3): 219-226, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26698172

RESUMO

Given that Campylobacter jejuni is recognized as the most common cause of bacterial gastroenteritis worldwide, recent findings showing comparable levels of Campylobacter concisus in patients with gastroenteritis would suggest that this bacterium is clinically important. The prevalence and abundance of Campylobacter concisus in stool samples collected from patients with acute gastroenteritis was examined using quantitative real-time PCR. The associated virulence determinants exotoxin 9 and zonula occludens toxin DNA were detected for Campylobacter concisus-infected samples using real-time PCR. Campylobacter concisus was detected at high prevalence in patients with gastroenteritis (49.7 %), higher than that observed for Campylobacter jejuni (∼5 %). The levels of Campylobacter concisus were putatively classified into clinically relevant and potentially transient subgroups based on a threshold developed using Campylobacter jejuni levels, as the highly sensitive real-time PCR probably detected transient passage of the bacterium from the oral cavity. A total of 18 % of patients were found to have clinically relevant levels of Campylobacter concisus, a significant number of which also had high levels of one of the virulence determinants. Of these patients, 78 % were found to have no other gastrointestinal pathogen identified in the stool, which strongly suggests a role for Campylobacter concisus in the aetiology of gastroenteritis in these patients. These results emphasize the need for diagnostic laboratories to employ identification protocols for emerging Campylobacter species. Clinical follow-up in patients presenting with high levels of Campylobacter concisus in the intestinal tract is needed, given that it has been associated with more chronic sequelae.


Assuntos
Infecções por Campylobacter/microbiologia , Campylobacter/classificação , Campylobacter/patogenicidade , Gastroenterite/microbiologia , Adolescente , Adulto , Criança , Pré-Escolar , Diarreia/microbiologia , Fezes/microbiologia , Feminino , Regulação Bacteriana da Expressão Gênica/fisiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Virulência , Adulto Jovem
20.
World J Gastroenterol ; 21(38): 10907-14, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26478682

RESUMO

AIM: To explore gastroenterologist perceptions towards and experience with faecal microbiota transplantation (FMT). METHODS: A questionnaire survey consisting of 17 questions was created to assess gastroenterologists' attitude towards and experience with FMT. This was anonymously distributed in hard copy format amongst attendees at gastroenterology meetings in Australia between October 2013 and April 2014. Basic descriptive statistical analyses were performed. RESULTS: Fifty-two clinicians participated. Twenty one percent had previously referred patients for FMT, 8% more than once. Ninety percent would refer patients with Clostridium difficile infection (CDI) for FMT if easily available, 37% for ulcerative colitis, 13% for Crohn's disease and 6% for irritable bowel syndrome. Six percent would not refer any indication, including recurrent CDI. Eighty-six percent would enroll patients in FMT clinical trials. Thirty-seven percent considered the optimal mode of FMT administration transcolonoscopic, 17% nasoduodenal, 13% enema and 8% oral capsule. The greatest concerns regarding FMT were: 42% lack of evidence, 12% infection risk, 10% non infectious adverse effects/lack of safety data, 10% aesthetic, 10% lack of efficacy, 4% disease exacerbation, and 2% inappropriate use; 6% had no concerns. Seventy seven percent believed there is a lack of accessibility while 52% had an interest in learning how to provide FMT. Only 6% offered FMT at their institution. CONCLUSION: Despite general enthusiasm, most gastroenterologists have limited experience with, or access to, FMT. The greatest concerns were lack of supportive evidence and safety issues. However a significant proportion would refer indications other than CDI for FMT despite insufficient evidence. These data provide guidance on where education and training are required.


Assuntos
Atitude do Pessoal de Saúde , Clostridioides difficile , Enterocolite Pseudomembranosa/terapia , Transplante de Microbiota Fecal , Gastroenterologia , Austrália , Colite Ulcerativa/terapia , Doença de Crohn/terapia , Transplante de Microbiota Fecal/efeitos adversos , Transplante de Microbiota Fecal/métodos , Acessibilidade aos Serviços de Saúde , Humanos , Síndrome do Intestino Irritável/terapia , Percepção
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