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1.
J Crohns Colitis ; 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31751459

RESUMO

BACKGROUND: The natural history of intestinal lesions in Crohn's disease [CD] is not fully understood. Although the extent of lesions at diagnosis usually defines the extent of the disease, some lesions seen at diagnosis, particularly aphthous ulcers [AUs], may resolve before follow-up. The aim of this study was to evaluate the outcomes of CD patients with colonic AUs seen at diagnosis. METHODS: CD patients with aphthous colitis at diagnosis who had been followed since 2001 were included in a case control study matched with two groups of controls: one without colonic involvement at diagnosis and a second group with colonic lesions more severe than AUs at diagnosis. RESULTS: Seventy-five patients were included, with a median follow-up of 7.3 years [interquartile range 2.7-9.8]. Seventy-one per cent of those having a second colonoscopy at least 6 months after diagnosis were stable or healed. Medical treatments were similar between the three groups. The AU group's rate of ileal surgery was similar to those without colitis. In multivariate analysis, the independent factors associated with ileal resection were ileal involvement (odds ratio [OR]: 8.8; 95% confidence interval [CI] [7.68-33.75]; p = 0.002) and the presence of severe colitis (OR = 0.5; 95% CI [0.32-0.79], p = 0.003). The risk of ileal surgery was not influenced by the presence of aphthous colitis (OR: 0.63; 95% CI [0.37-1.1]; p = 0.1). CONCLUSION: Aphthous colitis at diagnosis seems to resolve in most patients. This suggests that these lesions are of little clinical significance and may not need to be considered prior to ileal resection in CD or when making other important therapeutic decisions.

3.
Gut ; 68(12): 2111-2121, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31563878

RESUMO

Although faecal microbiota transplantation (FMT) has a well-established role in the treatment of recurrent Clostridioides difficile infection (CDI), its widespread dissemination is limited by several obstacles, including lack of dedicated centres, difficulties with donor recruitment and complexities related to regulation and safety monitoring. Given the considerable burden of CDI on global healthcare systems, FMT should be widely available to most centres.Stool banks may guarantee reliable, timely and equitable access to FMT for patients and a traceable workflow that ensures safety and quality of procedures. In this consensus project, FMT experts from Europe, North America and Australia gathered and released statements on the following issues related to the stool banking: general principles, objectives and organisation of the stool bank; selection and screening of donors; collection, preparation and storage of faeces; services and clients; registries, monitoring of outcomes and ethical issues; and the evolving role of FMT in clinical practice,Consensus on each statement was achieved through a Delphi process and then in a plenary face-to-face meeting. For each key issue, the best available evidence was assessed, with the aim of providing guidance for the development of stool banks in order to promote accessibility to FMT in clinical practice.

4.
Microbiome ; 7(1): 111, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31375137

RESUMO

BACKGROUND: Normal mammalian development and homeostasis are dependent upon the gut microbiota. Antibiotics, essential for the treatment and prophylaxis of bacterial infections, can have collateral effects on the gut microbiota composition, which can in turn have far-reaching and potentially deleterious consequences for the host. However, the magnitude and duration of such collateral effects appear to vary between individuals. Furthermore, the degree to which such perturbations affect the host response is currently unclear. We aimed to test the hypothesis that different human microbiomes have different responses to a commonly prescribed antibiotic and that these differences may impact the host response. METHODS: Germ-free mice (n = 30) humanized with the microbiota of two unrelated donors (A and B) were subjected to a 7-day antibiotic challenge with amoxicillin-clavulanate ("co-amoxiclav"). Microbiome and colonic transcriptome analysis was performed, pre (day 0) and post antibiotics (day 8) and subsequently into recovery (days 11 and 18). RESULTS: Unique community profiles were evident depending upon the donor, with donor A recipient mice being dominated by Prevotella and Faecalibacterium and donor B recipient mice dominated by Bacteroides and Parabacteroides. Donor A mice underwent a marked destabilization of their microbiota following antibiotic treatment, while donor B mice maintained a more stable profile. Dramatic and overlapping alterations in the host transcriptome were apparent following antibiotic challenge in both groups. Despite this overlap, donor A mice experienced a more significant alteration in gene expression and uniquely showed correlations between host pathways and key microbial genera. CONCLUSIONS: Germ-free mice humanized by different donor microbiotas maintain distinct microbiome profiles, which respond in distinct ways to antibiotic challenge and evince host responses that parallel microbiome disequilibrium. These results suggest that inter-individual variation in the gut microbiota may contribute to personalized host responses following microbiota perturbation.

5.
Ann Rheum Dis ; 78(10): 1398-1404, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31377728

RESUMO

OBJECTIVES: Familial Mediterranean fever (FMF) can be complicated by AA amyloidosis (AAA), though it remains unclear why only some patients develop amyloidosis. We examined the gut microbiota composition and inflammatory markers in patients with FMF complicated or not by AAA. METHODS: We analysed the gut microbiota of 34 patients with FMF without AAA, 7 patients with FMF with AAA, 19 patients with AAA of another origin, and 26 controls using 16S ribosomal RNA gene sequencing with the Illumina MiSeq platform. Associations between bacterial taxa and clinical phenotypes were evaluated using multivariate association with linear models statistical method. Blood levels of interleukin (IL)-1ß, IL-6, tumour necrosis factor-α and adipokines were assessed by ELISA; indoleamine 2,3-dioxygenase (IDO) activity was determined by high-performance liquid chromatography. RESULTS: Compared with healthy subjects, specific changes in faecal microbiota were observed in FMF and AAA groups. Several operational taxonomic units (OTUs) were associated with FMF. Moreover, two OTUs were over-represented in FMF-related AAA compared with FMF without AAA. Additionally, higher adiponectin levels and IDO activity were observed in FMF-related AAA compared with FMF without AAA (p<0.05). CONCLUSION: The presence of specific changes in faecal microbiota in FMF and in FMF-related AAA suggests that intestinal microorganisms may play a role in the pathogenesis of these diseases. These findings may offer an opportunity to use techniques for gut microbiota manipulation.

6.
Environ Microbiol ; 21(11): 4020-4031, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31325218

RESUMO

Antimicrobial peptides secreted by intestinal immune and epithelial cells are important effectors of innate immunity. They play an essential role in the maintenance of intestinal homeostasis by limiting microbial epithelium interactions and preventing unnecessary microbe-driven inflammation. Pancreatitis-associated protein (PAP) belongs to Regenerating islet-derived III proteins family and is a C-type (Ca+2 dependent) lectin. PAP protein plays a protective effect presenting anti-inflammatory properties able to reduce the severity of colitis, preserving gut barrier and epithelial inflammation. Here, we sought to determine whether PAP delivered at intestinal lumen by recombinant Lactococcus lactis strain (LL-PAP) before and after chemically induced colitis is able to reduce the severity in two models of colitis. After construction and characterization of our recombinant strains, we tested their effects in dinitro-benzenesulfonic-acid (DNBS) and Dextran sulfate sodium (DSS) colitis model. After the DNBS challenge, mice treated with LL-PAP presented less severe colitis compared with PBS and LL-empty-treated mice groups. After the DSS challenge, no protective effects of LL-PAP could be detected. We determined that after 5 days administration, LL-PAP increase butyrate producer's bacteria, especially Eubacterium plexicaudatum. Based on our findings, we hypothesize that a treatment with LL-PAP shifts the microbiota preventing the severity of colon inflammation in DNBS colitis model. These protective roles of LL-PAP in DNBS colitis model might be through intestinal microbiota modulation.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31262571

RESUMO

Primary sclerosing cholangitis is a chronic cholestatic liver disease, whose pathogenesis remains poorly understood. Several studies have shown that PSC patients harbor an impaired gut microbiota. A recent study confirmed that PSC patients displayed a bacterial dysbiosis, characterized by an increased abundance of three different bacteria: Klebsiella pneumoniae, Proteus mirabilis and Enterococcus gallinarum. This study also provides evidence for a possible mechanism of action of these bacteria: notably the formation of pores in gut epithelium leading to an increased gut permeability and the induction of liver inflammation characterized by an increased proportion of T helper 17 (TH17) cells. For the first time, strong data demonstrate not only an association between gut microbiota and primary sclerosing cholangitis but also a possible causal link.

9.
Gut ; 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31142586

RESUMO

OBJECTIVE: Following ileal resection for Crohn's disease (CD), recurrence is very frequent. Although several clinical risk factors of recurrence have been identified, predicting relapse remains challenging. Performing an ileocolonoscopy within the first year after surgery is currently recommended to assess endoscopic recurrence and to adjust the treatment. We took advantage of a large prospective multicentric cohort to investigate the role of the ileal mucosa-associated microbiota in postoperative endoscopic recurrence. PATIENTS AND METHODS: Ileal mucosa-associated microbiota was analysed by 16S sequencing at the time of surgery and/or of endoscopic evaluation in 201 patients (288 samples in total) prospectively recruited in France. RESULTS: Ileal mucosa-associated microbiota exhibits profound changes following surgery in CD. Compared with non-recurrence setting, endoscopic recurrence is associated with strong changes in ileal mucosa-associated microbiota that are highly reminiscent of those observed generally in ileal CD compared with healthy subjects with a reduction in alpha diversity, an increase in several members of the Proteobacteria phylum and a decrease in several members of the Lachnospiraceae and the Ruminococcaceae families within the Firmicutes phylum. At the time of surgery, we identified several bacterial taxa associated with endoscopic recurrence and that can better predict relapse than usual clinical risk factors. CONCLUSION: Surgery has an important impact on ileal mucosa-associated microbiota. Postoperative endoscopic recurrence is associated with changes in microbiota composition and alpha diversity. The gut microbiota has the potential to predict postoperative evolution and recurrence.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31085339

RESUMO

BACKGROUND & AIMS: The degree of histologic and endoscopic disease activity has been associated with an increased risk of colorectal neoplasia (CRN) in patients with inflammatory bowel diseases (IBDs), but no histologic scoring systems have been validated for determining risk of CRN. We investigated the association between histologic and endoscopic disease activity and risk of first CRN in patients with IBD who had negative findings from a surveillance colonoscopy. METHODS: We performed a retrospective analysis of consecutive patients who underwent at least 2 colonoscopies at Saint Antoine Hospital in France from January 1, 1996, through March 1, 2015, and whose first procedure was a surveillance colonoscopy. Histologic IBD activity was assessed by the Nancy histologic index. Patients were followed up for a mean 5.7 ± 3.3 years. Logistic regression and generalized estimating equations were used to identify clinical, endoscopic, and histologic factors associated with detection of neoplasia in the inflamed colon mucosa. RESULTS: Among 398 patients who underwent 1277 colonoscopies, we identified 45 patients with CRN. Factors associated with CRN were primary sclerosing cholangitis (odds ratio [OR], 2.65; 95% CI, 1.06-6.61; P = .04), age (OR per 1-year increase, 1.04; 95% CI, 1.01-1.07; P = .003), and mean Nancy histologic index during follow-up evaluation (per 1-unit increase, OR, 1.69; 95% CI, 1.29-2.21; P < .001). After adjustment for established factors, chronic disease activity defined as detection of ulcerations at more than 50% of colonoscopies was not associated with an increased risk of CRN (OR, 1.24; 95% CI, 0.53-2.91; P = .62). CONCLUSIONS: In addition to established risk factors, we associated Nancy histologic index scores with development of CRN. Histologic findings based on the Nancy histologic index therefore should be included in determining the risk of colonic neoplasia in patients with IBD.

12.
Gut ; 2019 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-31003979

RESUMO

OBJECTIVE: Patients with primary sclerosing cholangitis (PSC) were previously shown to display a bacterial gut dysbiosis but fungal microbiota has never been examined in these patients. The aim of this study was to assess the fungal gut microbiota in patients with PSC. DESIGN: We analysed the faecal microbiota of patients with PSC and concomitant IBD (n=27), patients with PSC and no IBD (n=22), patients with IBD and no PSC (n=33) and healthy subjects (n=30). Bacterial and fungal composition of the faecal microbiota was determined using 16S and ITS2 sequencing, respectively. RESULTS: We found that patients with PSC harboured bacterial dysbiosis characterised by a decreased biodiversity, an altered composition and a decreased correlation network density. These alterations of the microbiota were associated with PSC, independently of IBD status. For the first time, we showed that patients with PSC displayed a fungal gut dysbiosis, characterised by a relative increase in biodiversity and an altered composition. Notably, we observed an increased proportion of Exophiala and a decreased proportion of Saccharomyces cerevisiae. Compared with patients with IBD and healthy subjects, the gut microbiota of patients with PSC exhibited a strong disruption in bacteria-fungi correlation network, suggesting an alteration in the interkingdom crosstalk. CONCLUSION: This study demonstrates that bacteria and fungi contribute to gut dysbiosis in PSC.

13.
Nat Rev Gastroenterol Hepatol ; 16(6): 331-345, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30824884

RESUMO

The gut microbiota is a dense and diverse ecosystem that is involved in many physiological functions as well as in disease pathogenesis. It is dominated by bacteria, which have been extensively studied in the past 15 years; however, other microorganisms, such as fungi, phages, archaea and protists, are also present in the gut microbiota. Exploration of the fungal component, namely, the mycobiota, is at an early stage, and several specific technical challenges are associated with mycobiota analysis. The number of fungi in the lower gastrointestinal tract is far lower than that of bacteria, but fungal cells are much larger and much more complex than bacterial cells. In addition, a role of the mycobiota in disease, notably in IBD, is indicated by both descriptive data in humans and mechanistic data in mice. Interactions between bacteria and fungi within the gut, their functional roles and their interplay with the host and its immune system are fascinating areas that researchers are just beginning to investigate. In this Review, we discuss the newest data on the gut mycobiota and explore both the technical aspects of its study and its role in health and gastrointestinal diseases.


Assuntos
Gastroenteropatias/microbiologia , Microbioma Gastrointestinal/fisiologia , Trato Gastrointestinal/microbiologia , Interações Hospedeiro-Patógeno/fisiologia , Interações Microbianas/fisiologia , Animais , Humanos
14.
PLoS Genet ; 15(3): e1008018, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30849075

RESUMO

Several bacteria in the gut microbiota have been shown to be associated with inflammatory bowel disease (IBD), and dozens of IBD genetic variants have been identified in genome-wide association studies. However, the role of the microbiota in the etiology of IBD in terms of host genetic susceptibility remains unclear. Here, we studied the association between four major genetic variants associated with an increased risk of IBD and bacterial taxa in up to 633 IBD cases. We performed systematic screening for associations, identifying and replicating associations between NOD2 variants and two taxa: the Roseburia genus and the Faecalibacterium prausnitzii species. By exploring the overall association patterns between genes and bacteria, we found that IBD risk alleles were significantly enriched for associations concordant with bacteria-IBD associations. To understand the significance of this pattern in terms of the study design and known effects from the literature, we used counterfactual principles to assess the fitness of a few parsimonious gene-bacteria-IBD causal models. Our analyses showed evidence that the disease risk of these genetic variants were likely to be partially mediated by the microbiome. We confirmed these results in extensive simulation studies and sensitivity analyses using the association between NOD2 and F. prausnitzii as a case study.


Assuntos
Microbioma Gastrointestinal/genética , Interações entre Hospedeiro e Microrganismos/genética , Doenças Inflamatórias Intestinais/genética , Doenças Inflamatórias Intestinais/microbiologia , Adulto , Proteínas Adaptadoras de Sinalização CARD/genética , Clostridiales/genética , Clostridiales/isolamento & purificação , Clostridiales/patogenicidade , Faecalibacterium prausnitzii/genética , Faecalibacterium prausnitzii/isolamento & purificação , Faecalibacterium prausnitzii/patogenicidade , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Humanos , Doenças Inflamatórias Intestinais/etiologia , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , Proteína Adaptadora de Sinalização NOD2/genética , Polimorfismo de Nucleotídeo Único
15.
Gut ; 68(11): 1961-1970, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30792246

RESUMO

T cell clonal expansions are present in the inflamed mucosa of patients with Crohn's disease (CD) and may be implicated in postoperative recurrence after ileocolonic resection. METHODS: T cell receptor (TCR) analysis was performed in 57 patients included in a prospective multicentre cohort. Endoscopic recurrence was defined by a Rutgeerts score >i0. DNA and mRNA were extracted from biopsies collected from the surgical specimen and endoscopy, and analysed by high throughput sequencing and microarray, respectively. RESULTS: TCR repertoire in the mucosa of patients with CD displayed diverse clonal expansions. Active smokers at time of surgery had a significantly increased proportion of clonal expansions as compared with non-smokers (25.9%vs17.9%, p=0.02). The percentage of high frequency clones in the surgical specimen was significantly higher in patients with recurrence and correlated with postoperative endoscopic recurrence (area under the curve (AUC) 0.69, 95% CI 0.54 to 0.83). All patients with clonality above 26.8% (18/57) had an endoscopic recurrence. These patients with a high clonality were more frequently smokers than patients with a low clonality (61% vs 23%, p=0.005). The persistence of a similar TCR repertoire at postoperative endoscopy was associated with smoking and disease recurrence. Patients with high clonality showed increased expression of genes associated with CD8 T cells and reduced expression of inflammation-related genes. Expanded clones were found predominantly in the CD8 T cell compartment. CONCLUSION: Clonal T cell expansions are implicated in postoperative endoscopic recurrence. CD patients with increased proportion of clonal T cell expansions in the ileal mucosa represent a subgroup associated with smoking and where pathogenesis appears as T cell driven. TRIAL REGISTRATION NUMBER: NCT03458195.


Assuntos
Doença de Crohn/etiologia , Doença de Crohn/cirurgia , Ileíte/etiologia , Ileíte/cirurgia , Receptores de Antígenos de Linfócitos T/metabolismo , Fumar , Adulto , Idoso , Estudos de Coortes , Doença de Crohn/patologia , Feminino , Humanos , Ileíte/patologia , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Recidiva , Resultado do Tratamento , Adulto Jovem
16.
Haematologica ; 104(8): 1682-1688, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30733264

RESUMO

Fecal microbiota transplantation is an effective treatment in recurrent Clostridium difficile infection. Promising results to eradicate multidrug-resistant bacteria have also been reported with this procedure, but there are safety concerns in immunocompromised patients. We report results in ten adult patients colonized with multidrug-resistant bacteria, undergoing fecal microbiota transplantation before (n=4) or after (n=6) allogeneic hematopoietic stem cell transplantation for hematologic malignancies. were obtained from healthy related or unrelated donors. Fecal material was delivered either by enema or via nasogastric tube. Patients were colonized or had infections from either carbapenemase-producing bacteria (n=8) or vancomycin-resistant enterococci (n=2). Median age at fecal microbiota transplantation was 48 (range, 16-64) years. Three patients needed a second transplant from the same donor due to initial failure of the procedure. With a median follow up of 13 (range, 4-40) months, decolonization was achieved in seven of ten patients. In all patients, fecal micro-biota transplantation was safe: one patient presented with constipation during the first five days after FMT and two patients had grade I diarrhea. One case of gut grade III acute graft-versus-host disease occurred after fecal microbiota transplantation. In patients carrying or infected by multidrug-resistant bacteria, fecal microbiota transplantation is an effective and safe decolonization strategy, even in those with hematologic malignancies undergoing hematopoietic stem cell transplantation.

17.
JAMA ; 321(8): 773-785, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30806694

RESUMO

Importance: Use of thiopurines may be limited by myelosuppression. TPMT pharmacogenetic testing identifies only 25% of at-risk patients of European ancestry. Among patients of East Asian ancestry, NUDT15 variants are associated with thiopurine-induced myelosuppression (TIM). Objective: To identify genetic variants associated with TIM among patients of European ancestry with inflammatory bowel disease (IBD). Design, Setting, and Participants: Case-control study of 491 patients affected by TIM and 679 thiopurine-tolerant unaffected patients who were recruited from 89 international sites between March 2012 and November 2015. Genome-wide association studies (GWAS) and exome-wide association studies (EWAS) were conducted in patients of European ancestry. The replication cohort comprised 73 patients affected by TIM and 840 thiopurine-tolerant unaffected patients. Exposures: Genetic variants associated with TIM. Main Outcomes and Measures: Thiopurine-induced myelosuppression, defined as a decline in absolute white blood cell count to 2.5 × 109/L or less or a decline in absolute neutrophil cell count to 1.0 × 109/L or less leading to a dose reduction or drug withdrawal. Results: Among 1077 patients (398 affected and 679 unaffected; median age at IBD diagnosis, 31.0 years [interquartile range, 21.2 to 44.1 years]; 540 [50%] women; 602 [56%] diagnosed as having Crohn disease), 919 (311 affected and 608 unaffected) were included in the GWAS analysis and 961 (328 affected and 633 unaffected) in the EWAS analysis. The GWAS analysis confirmed association of TPMT (chromosome 6, rs11969064) with TIM (30.5% [95/311] affected vs 16.4% [100/608] unaffected patients; odds ratio [OR], 2.3 [95% CI, 1.7 to 3.1], P = 5.2 × 10-9). The EWAS analysis demonstrated an association with an in-frame deletion in NUDT15 (chromosome 13, rs746071566) and TIM (5.8% [19/328] affected vs 0.2% [1/633] unaffected patients; OR, 38.2 [95% CI, 5.1 to 286.1], P = 1.3 × 10-8), which was replicated in a different cohort (2.7% [2/73] affected vs 0.2% [2/840] unaffected patients; OR, 11.8 [95% CI, 1.6 to 85.0], P = .03). Carriage of any of 3 coding NUDT15 variants was associated with an increased risk (OR, 27.3 [95% CI, 9.3 to 116.7], P = 1.1 × 10-7) of TIM, independent of TPMT genotype and thiopurine dose. Conclusions and Relevance: Among patients of European ancestry with IBD, variants in NUDT15 were associated with increased risk of TIM. These findings suggest that NUDT15 genotyping may be considered prior to initiation of thiopurine therapy; however, further study including additional validation in independent cohorts is required.


Assuntos
Colite Ulcerativa/genética , Doença de Crohn/genética , Metiltransferases/metabolismo , Pirofosfatases/genética , Adolescente , Adulto , Estudos de Casos e Controles , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Doença de Crohn/tratamento farmacológico , Doença de Crohn/metabolismo , Grupo com Ancestrais do Continente Europeu , Exoma , Feminino , Estudo de Associação Genômica Ampla , Haplótipos , Humanos , Contagem de Leucócitos , Masculino , Metiltransferases/genética , Metiltransferases/uso terapêutico , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/métodos , Adulto Jovem
18.
Front Immunol ; 10: 143, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30787928

RESUMO

The human colonic mucosa contains regulatory type 1-like (Tr1-like, i.e., IL-10-secreting and Foxp3-negative) T cells specific for the gut Clostridium Faecalibacterium prausnitzii (F. prausnitzii), which are both decreased in Crohn's disease patients. These data, together with the demonstration, in mice, that colonic regulatory T cells (Treg) induced by Clostridium bacteria are key players in colon homeostasis, support a similar role for F. prausnitzii-specific Treg in the human colon. Here we assessed the mechanisms whereby F. prausnitzii induces human colonic Treg. We demonstrated that F. prausnitzii, but not related Clostridia, skewed human dendritic cells to prime IL-10-secreting T cells. Accordingly, F. prausnitzii induced dendritic cells to express a unique array of potent Tr1/Treg polarizing molecules: IL-10, IL-27, CD39, IDO-1, and PDL-1 and, following TLR4 stimulation, inhibited their up-regulation of costimulation molecules as well as their production of pro-inflammatory cytokines IL-12 (p35 and p40) and TNFα. We further showed that these potent tolerogenic effects relied on F. prausnitzii-induced TLR2/6 triggering, JNK signaling and CD39 ectonucleotidase activity, which was induced by IDO-1 and IL-27. These data, together with the presence of F. prausnitzii-specific Tr1-like Treg in the human colon, point out to dendritic cells polarization by F. prausnitzii as the first described cellular mechanism whereby the microbiota composition may affect human colon homeostasis. Identification of F. prausnitzii-induced mediators involved in Tr1-like Treg induction by dendritic cells opens therapeutic avenues for the treatment of inflammatory bowel diseases.

19.
Talanta ; 195: 593-598, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30625588

RESUMO

In this study, we validated a method for quantifying 20 tryptophan (Trp) catabolites by liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) in 4 different matrices (urine, serum, intestinal contents and liver). The detection limit for all metabolites ranged between 0.015 and 11.25 nmol/L and the dynamic range of the calibration curves were adjusted to allow quantification of metabolites at endogenous levels. Matrix effects were evaluated using isotope labeled internal standards. Reproducibility in the 4 matrices was characterized by CV = 6.2% with an accuracy of 6.6%. Our method has been applied to the determination and quantification of 20 metabolites concentrations in 5 different mouse compartments (plus cecal contents). Our results show that our approach allows for a global exploration of the Trp metabolism by quantifying a large number of Trp metabolites, at the individual level by multi-matrix approach.


Assuntos
Ceco/química , Conteúdo Gastrointestinal/química , Fígado/química , Triptofano/análise , Triptofano/metabolismo , Animais , Ceco/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Cinurenina/metabolismo , Fígado/metabolismo , Espectrometria de Massas , Camundongos , Reprodutibilidade dos Testes , Serotonina/metabolismo
20.
Front Microbiol ; 9: 2849, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30524414

RESUMO

Introduction: Bile acids (BA) influence germination and growth of Clostridium difficile. Ursodeoxycholic acid (UDCA), a BA minor in human, used for cholestatic liver diseases, inhibits germination and growth of C. difficile in vitro, but was never tested in vivo with an infectious challenge versus control. We hypothesized that UDCA could prevent CDI. We evaluated the effects of UDCA on C. difficile in vitro and in hamsters, with pharmacokinetics study and with an infectious challenge. Then, we studied CDI incidence in UDCA-treated patients. Methods: We evaluated germination and growth of C. difficile, with 0.01, 0.05, and 0.1% UDCA. We analyzed fecal BA of hamsters receiving antibiotics and UDCA (50 mg/kg/day), antibiotics, or UDCA alone. Then, we challenged with spores of C. difficile at D6 hamsters treated with UDCA (50 mg/kg/day) from D1 to D13, versus control. In human, we analyzed the database of a cohort on CDI in acute flares of inflammatory bowel disease (IBD). As PSC-IBD patients were under UDCA treatment, we compared PSC-IBD patients to IBD patients without PSC. Results: In vitro, UDCA inhibited germination and growth of C. difficile at 0.05 and 0.1%, competing with 0.1% TCA (with 0.1%: 0.05% ± 0.05% colony forming unit versus 100% ± 0%, P < 0.0001). In hamsters, UDCA reached high levels only when administered with antibiotics (43.5% UDCA at D5). Without antibiotics, UDCA was in small amount in feces (max. 4.28%), probably because of UDCA transformation into LCA by gut microbiota. During infectious challenge, mortality was similar in animals treated or not with UDCA (62.5%, n = 5/8, P = 0.78). UDCA percentage was high, similar and with the same kinetics in dead and surviving hamsters. However, dead hamsters had a higher ratio of primary over secondary BA compared to surviving hamsters. 9% (n = 41/404) of IBD patients without PSC had a CDI, versus 25% (n = 4/12) of PSC-IBD patients treated with UDCA. Conclusion: We confirmed the inhibitory effect of UDCA on growth and germination of C. difficile in vitro, with 0.05 or 0.1% UDCA. However, in our hamster model, UDCA was inefficient to prevent CDI, despite high levels of UDCA in feces. Patients with PSC-IBD treated with UDCA did not have less CDI than IBD patients.

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