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1.
Gastroenterology ; 156(1): 46-58.e7, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30009817

RESUMO

BACKGROUND & AIMS: The existence of postinfection irritable bowel syndrome (PI-IBS) has been substantiated by epidemiology studies conducted in diverse geographic and clinical settings. However, the available evidence has not been well summarized, and there is little guidance for diagnosis and treatment of PI-IBS. The ROME Foundation has produced a working team report to summarize the available evidence on the pathophysiology of PI-IBS and provide guidance for diagnosis and treatment, based on findings reported in the literature and clinical experience. METHODS: The working team conducted an evidence-based review of publication databases for articles describing the clinical features (diagnosis), pathophysiology (intestinal sensorimotor function, microbiota, immune dysregulation, barrier dysfunction, enteroendocrine pathways, and genetics), and animal models of PI-IBS. We used a Delphi-based consensus system to create guidelines for management of PI-IBS and a developed treatment algorithm based on published findings and experiences of team members. RESULTS: PI-IBS develops in about 10% of patients with infectious enteritis. Risk factors include female sex, younger age, psychological distress during or before acute gastroenteritis, and severity of the acute episode. The pathogenesis of PI-PBS appears to involve changes in the intestinal microbiome as well as epithelial, serotonergic, and immune system factors. However, these mechanisms are incompletely understood. There are no evidence-based, effective pharmacologic strategies for treatment of PI-IBS. We provide a consensus-based treatment algorithm, based on clinical presentation and potential disease mechanisms. CONCLUSIONS: Based on a systematic review of the literature and team experience, we summarize the clinical features, pathophysiology (from animal models and human studies), and progression of PI-IBS. Based on these findings, we present an algorithm for diagnosis and treatment of PI-IBS based on team consensus. We also propose areas for future investigation.


Assuntos
Doenças Transmissíveis/diagnóstico , Doenças Transmissíveis/terapia , Gastroenterite/diagnóstico , Gastroenterite/terapia , Síndrome do Intestino Irritável/diagnóstico , Síndrome do Intestino Irritável/terapia , Algoritmos , Animais , Tomada de Decisão Clínica , Doenças Transmissíveis/epidemiologia , Consenso , Técnica Delphi , Gastroenterite/epidemiologia , Humanos , Síndrome do Intestino Irritável/etiologia , Valor Preditivo dos Testes , Prevalência , Prognóstico , Fatores de Risco
2.
Microb Pathog ; 120: 71-78, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29709685

RESUMO

In the current study, the biocontrol potential of a novel strain Bacillus sp. PPM3 isolated from marine sediment from the Red Sea in Hurghada, Egypt is recognized. This novel strain was selected out of 32 isolates based on its ability to suppress the growth of four plant pathogenic fungi: Aspergillus flavus, Fusarium graminearum, Mucor sp. and Alternaria sp. The new marine strain was identified and characterized by phenotypic and molecular approaches. The culture filtrate of Bacillus sp. PPM3 suppressed the growth and spore germination of all tested fungi in vitro with the highest value of inhibition reported for Mucor sp. (97.5%). The antifungal effect of the culture filtrate from the strain PPM3 was due to production of highly stable secondary metabolites resistant to extreme pH, temperature and enzymatic treatments. A PCR analysis confirmed the expression of genes involved in the synthesis of antifungal lipopeptides: iturin, bacillomycin D, mycosubtilin and surfactin. In a greenhouse experiment strain PPM3 effectively reduced disease incidence of F. graminearum in maize plants and displayed additional plant growth stimulating effect. The results show that novel marine strain PPM3 could have a potential in commercial application as biocontrol agent for treatment of various plant diseases caused by soil-borne and postharvest pathogenic fungi.


Assuntos
Antifúngicos/farmacologia , Bacillus/isolamento & purificação , Bacillus/metabolismo , Agentes de Controle Biológico/farmacologia , Sedimentos Geológicos/microbiologia , Doenças das Plantas/prevenção & controle , Alternaria/efeitos dos fármacos , Alternaria/crescimento & desenvolvimento , Antifúngicos/metabolismo , Peptídeos Catiônicos Antimicrobianos , Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/crescimento & desenvolvimento , Bacillus/enzimologia , Bacillus/genética , DNA Bacteriano/genética , Egito , Fungos/efeitos dos fármacos , Fungos/patogenicidade , Fusarium/efeitos dos fármacos , Fusarium/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Oceano Índico , Lipopeptídeos/metabolismo , Lipoproteínas/metabolismo , Mucor/efeitos dos fármacos , Mucor/crescimento & desenvolvimento , Peptídeos/metabolismo , Peptídeos Cíclicos/metabolismo , Desenvolvimento Vegetal , Doenças das Plantas/microbiologia , RNA Ribossômico 16S/genética , Metabolismo Secundário , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Especificidade da Espécie , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Temperatura , Zea mays/crescimento & desenvolvimento , Zea mays/microbiologia
3.
Gut ; 66(4): 569-580, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28087657

RESUMO

Faecal microbiota transplantation (FMT) is an important therapeutic option for Clostridium difficile infection. Promising findings suggest that FMT may play a role also in the management of other disorders associated with the alteration of gut microbiota. Although the health community is assessing FMT with renewed interest and patients are becoming more aware, there are technical and logistical issues in establishing such a non-standardised treatment into the clinical practice with safety and proper governance. In view of this, an evidence-based recommendation is needed to drive the practical implementation of FMT. In this European Consensus Conference, 28 experts from 10 countries collaborated, in separate working groups and through an evidence-based process, to provide statements on the following key issues: FMT indications; donor selection; preparation of faecal material; clinical management and faecal delivery and basic requirements for implementing an FMT centre. Statements developed by each working group were evaluated and voted by all members, first through an electronic Delphi process, and then in a plenary consensus conference. The recommendations were released according to best available evidence, in order to act as guidance for physicians who plan to implement FMT, aiming at supporting the broad availability of the procedure, discussing other issues relevant to FMT and promoting future clinical research in the area of gut microbiota manipulation. This consensus report strongly recommends the implementation of FMT centres for the treatment of C. difficile infection as well as traces the guidelines of technicality, regulatory, administrative and laboratory requirements.


Assuntos
Clostridioides difficile , Enterocolite Pseudomembranosa/terapia , Transplante de Microbiota Fecal , Seleção de Pacientes , Manejo de Espécimes/métodos , Seleção do Doador , Europa (Continente) , Medicina Baseada em Evidências , Transplante de Microbiota Fecal/efeitos adversos , Transplante de Microbiota Fecal/métodos , Transplante de Microbiota Fecal/normas , Instalações de Saúde , Unidades Hospitalares/organização & administração , Humanos
4.
Am J Gastroenterol ; 110(2): 278-87, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25623659

RESUMO

Irritable bowel syndrome (IBS) is a heterogeneous functional disorder with a multifactorial etiology that involves the interplay of both host and environmental factors. Among environmental factors relevant for IBS etiology, the diet stands out given that the majority of IBS patients report their symptoms to be triggered by meals or specific foods. The diet provides substrates for microbial fermentation, and, as the composition of the intestinal microbiota is disturbed in IBS patients, the link between diet, microbiota composition, and microbial fermentation products might have an essential role in IBS etiology. In this review, we summarize current evidence regarding the impact of diet and the intestinal microbiota on IBS symptoms, as well as the reported interactions between diet and the microbiota composition. On the basis of the existing data, we suggest pathways (mechanisms) by which diet components, via the microbial fermentation, could trigger IBS symptoms. Finally, this review provides recommendations for future studies that would enable elucidation of the role of diet and microbiota and how these factors may be (inter)related in the pathophysiology of IBS.


Assuntos
Comportamento Alimentar , Intestinos/fisiopatologia , Síndrome do Intestino Irritável/fisiopatologia , Microbiota/fisiologia , Fermentação/fisiologia , Humanos , Intestinos/microbiologia , Síndrome do Intestino Irritável/etiologia , Síndrome do Intestino Irritável/microbiologia
5.
BMC Microbiol ; 13: 12, 2013 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-23339708

RESUMO

BACKGROUND: Deviations in composition and diversity of intestinal microbiota in infancy have been associated with both the development and recurrence of atopic eczema. Thus, we decided to use a deep and global microarray-based method to characterize the diversity and temporal changes of the intestinal microbiota in infancy and to define specific bacterial signatures associated with eczema. Faecal microbiota at 6 and 18 months of age were analysed from 34 infants (15 with eczema and 19 healthy controls) selected from a prospective follow-up study based on the availability of faecal samples. The infants were originally randomized to receive either Lactobacillus rhamnosus GG or placebo. RESULTS: Children with eczema harboured a more diverse total microbiota than control subjects as assessed by the Simpson's reciprocal diversity index of the microarray profiles. Composition of the microbiota did not differ between study groups at age of 6 months, but was significantly different at age of 18 months as assessed by MCPP (p=0.01). At this age healthy children harboured 3 -fold greater amount of members of the Bacteroidetes (p=0.01). Microbiota of children suffering from eczema had increased abundance of the Clostridium clusters IV and XIVa, which are typically abundant in adults. Probiotic Lactobacillus rhamnosus GG supplementation in early infancy was observed to have minor long-term effects on the microbiota composition. CONCLUSION: A diverse and adult-type microbiota in early childhood is associated with eczema and it may contribute to the perpetuation of eczema.


Assuntos
Bactérias/classificação , Bactérias/genética , Biodiversidade , Dermatite Atópica/microbiologia , Trato Gastrointestinal/microbiologia , Metagenoma , Análise em Microsséries , Feminino , Seguimentos , Humanos , Lactente , Masculino , Placebos/administração & dosagem , Probióticos/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto
6.
J Biomed Mater Res A ; 111(7): 962-974, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36571468

RESUMO

In this study, polycaprolactone (PCL), as a biocompatible polymer was functionalized by addition of medicinal plant extract- Achillea millefolium L. (yarrow). Nanofiber mats were fabricated from PCL solutions containing dry yarrow extract in four concentrations (5%, 10%, 15%, and 20% relative to the weight of the polymer) by using blend electrospinning method. The nanofibers were characterized for their biological, mechanical and drug release behavior. In vitro release of yarrow polyphenols from the electrospun PCL nanofibers over a period of 5 days showed the release of up to 98% of the total loaded polyphenols. The released polyphenols retained its antioxidant activity, which was determined by DPPH assay. Electrospun PCL/yarrow nanofiber mats exhibited the antibacterial effect against Staphylococcus aureus, but had no effect on the growth of Pseudomonas aeruginosa. All PCL/yarrow nanofiber mats had improved mechanical properties compared to the neat PCL nanofibers, as evident by an increase in Young's modulus of elasticity (up to 5.7 times), the tensile strength (up to 5.5 times), and the strain at break (up to 1.45 times). Based on our results, yarrow-loaded PCL nanofiber mats appeared to be multi-functional biomaterials suitable for the production of catheter-coating materials, patches, or gauzes with antibacterial and antioxidant properties.


Assuntos
Achillea , Nanofibras , Materiais Biocompatíveis/química , Antioxidantes , Nanofibras/química , Antibacterianos/química , Poliésteres/química
7.
J Fungi (Basel) ; 9(3)2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36983496

RESUMO

Helicobacter pylori eradication is characterized by decreasing successful eradication rates. Although treatment failure is primarily associated with resistance to antibiotics, other unknown factors may influence the eradication outcome. This study aimed to assess the presence of the antibiotics resistance genes in H. pylori and the presence of Candida spp., which are proposed to be endosymbiotic hosts of H. pylori, in gastric biopsies of H. pylori-positive patients while simultaneously assessing their relationship. The detection and identification of Candida yeasts and the detection of mutations specific for clarithromycin and fluoroquinolones were performed by using the real-time PCR (RT-PCR) method on DNA extracted from 110 gastric biopsy samples of H. pylori-positive participants. Resistance rate to clarithromycin and fluoroquinolone was 52% and 47%, respectively. Antibiotic resistance was associated with more eradication attempts (p < 0.05). Candida species were detected in nine (8.18%) patients. Candida presence was associated with older age (p < 0.05). A high rate of antibiotic resistance was observed, while Candida presence was scarce, suggesting that endosymbiosis between H. pylori and Candida may not be a major contributing factor to the eradication failure. However, the older age favored Candida gastric mucosa colonization, which could contribute to gastric pathologies and microbiome dysbiosis.

8.
Gastroenterology ; 141(5): 1792-801, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21820992

RESUMO

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) has been associated with disruptions to the intestinal microbiota, but studies have had limited power, coverage, and depth of analysis. We aimed to define microbial populations that can be used discriminate the fecal microbiota of patients with IBS from that of healthy subjects and correlate these with IBS intestinal symptom scores. METHODS: The microbiota composition was assessed by global and deep molecular analysis of fecal samples from 62 patients with IBS patients and 46 healthy individuals (controls). We used a comprehensive and highly reproducible phylogenetic microarray in combination with quantitative polymerase chain reaction. RESULTS: The intestinal microbiota of IBS patients differed significantly (P = .0005) from that of controls. The microbiota of patients, compared with controls, had a 2-fold increased ratio of the Firmicutes to Bacteroidetes (P = .0002). This resulted from an approximately 1.5-fold increase in numbers of Dorea, Ruminococcus, and Clostridium spp (P < .005); a 2-fold decrease in the number of Bacteroidetes (P < .0001); a 1.5-fold decrease in numbers of Bifidobacterium and Faecalibacterium spp (P < .05); and, when present, a 4-fold lower average number of methanogens (3.50 × 10(7) vs 8.74 × 10(6) cells/g feces; P = .003). Correlation analysis of the microbial groups and IBS symptom scores indicated the involvement of several groups of Firmicutes and Proteobacteria in the pathogenesis of IBS. CONCLUSIONS: Global and deep molecular analysis of fecal samples indicates that patients with IBS have a different composition of microbiota. This information might be used to develop better diagnostics and ultimately treatments for IBS.


Assuntos
Fezes/microbiologia , Síndrome do Intestino Irritável/microbiologia , Metagenoma/genética , Filogenia , Adulto , Idoso , Bifidobacterium/genética , Bifidobacterium/isolamento & purificação , Estudos de Casos e Controles , Clostridium/genética , Clostridium/isolamento & purificação , Feminino , Humanos , Síndrome do Intestino Irritável/diagnóstico , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Ruminococcus/genética , Ruminococcus/isolamento & purificação
9.
Environ Microbiol ; 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23286720

RESUMO

The microbiota that colonizes the human intestinal tract is complex and its structure is specific for each of us. In this study we expand the knowledge about the stability of the subject-specific microbiota and show that this ecosystem is stable in short-term intervals (< 1 year) but also during long periods of time (> 10 years). The faecal microbiota composition of five unrelated and healthy subjects was analysed using a comprehensive and highly reproducible phylogenetic microarray, the HITChip. The results show that the use of antibiotics, application of specific dietary regimes and distant travelling have limited impact on the microbiota composition. Several anaerobic genera, including Bifidobacterium and a number of genera within the Bacteroidetes and the Firmicutes phylum, exhibit significantly higher similarity than the total microbiota. Although the gut microbiota contains subject-specific species, the presence of which is preserved throughout the years, their relative abundance changes considerably. Consequently, the recently proposed enterotype status appears to be a varying characteristic of the microbiota. Our data show that the intestinal microbiota contains a core community of permanent colonizers, and that environmentally introduced changes of the microbiota throughout adulthood are primarily affecting the abundance but not the presence of specific microbial species.

10.
Nutrients ; 14(6)2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35334928

RESUMO

The present study aimed to investigate the neuroprotective effects of the vitamin B complex (B1, B2, B3, B5, B6, and B12-VBC), by studying the changes in the femoral nerve, quadriceps muscle, popliteal lymph nodes and gut microbiota in the rat model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). VBC treatment attenuated clinical signs of EAE during the disease, and reduced the duration of EAE thereby contributing to a faster recovery. In VBC-treated EAE rats, a significant decrease in nerve and muscle nuclear density was revealed during the onset period of the disease, while a marked increase was detected at the end of the disease, compared with untreated EAE rats. In the lymph nodes of VBC-treated EAE rats, a fewer number of lymphoid follicles in the cortical area and smaller epithelioid granulomas were detected. The changes in microbiota composition were examined using 16S rRNA gene sequencing and bioinformatics analysis, which revealed the potential of VBC treatment in establishing and/or maintaining gut microbiota homeostasis. Finally, the present study demonstrated that VBC treatment ameliorated the cellular changes in the affected peripheral nerve, muscles innervated by this nerve, and the gut microbiota dysbiosis which occurred during the EAE.


Assuntos
Encefalomielite Autoimune Experimental , Microbioma Gastrointestinal , Complexo Vitamínico B , Animais , Disbiose , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , RNA Ribossômico 16S/genética , Ratos , Complexo Vitamínico B/farmacologia
11.
Front Nutr ; 8: 688843, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34409062

RESUMO

Medicinal plants and their extracts contain substantial quantities of polyphenols. As metabolically active plant metabolites, polyphenols are food components with a wide range of biological activities. Given their poor absorbability in the digestive tract their activity toward the human host is typically mediated through interaction with intestinal microbes. As a result, polyphenols comprise a novel group of prebiotics. In this study, we tested the effect of five polyphenol-rich extracts from four medicinal herbs on the growth of probiotic and pathogenic microbes. The studied medicinal herbs were Gentiana asclepiadea L. (willow gentian), Hypericum perforatum L. (St. John's wort), Satureja montana L. (winter savory), and Achillea millefolium L. (yarrow). All these plants are traditionally used for the treatment of digestive problems. Extracts were prepared using safe solvent combinations. We tested the impact of addition of plant extracts on the growth of three probiotic lactobacilli and probiotic yeast Saccharomyces boulardii. The effect of addition of plant extracts to liquid media (concentration range 0.25-10 mg/mL) on the growth of probiotics, was tested in vitro. The antimicrobial activity of the extracts was tested against several opportunistic bacteria and yeast. St. John's wort, winter savory, and willow gentian extracts showed a stimulative effect on probiotic yeast growth, while the highest growth-stimulating effect was achieved when microwave-assisted yarrow extract was used in the concentration of 0.5 mg/mL. Under these conditions growth of S. boulardii was increased 130-fold. In addition, the yarrow extract stimulated the growth of Lactiplantibacillus plantarum 299v. The growth of two Lacticasibacillus rhamnosus strains was not stimulated by the addition of any extracts. Our results show that plant polyphenol-rich extracts can influence the growth of microorganisms that are typical members of the intestinal microbiota. For the first time we demonstrate that probiotic yeast growth can be stimulated by extracts of medicinal herbs, which when accompanied by suppression of Candida yeasts suggests a potential benefit of the treatment in diseases that are associated with fungal dysbiosis.

12.
J Gastrointestin Liver Dis ; 30(2): 274-282, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-33951119

RESUMO

Non-alcoholic fatty liver disease and colonic diverticulosis are widespread, obesity-related diseases. It has recently become clear that non-alcoholic fatty liver disease is a systemic disease and may play a key role in metabolic syndrome; therefore, the term metabolic-dysfunction-associated fatty liver disease has been introduced in the literature. Excess visceral adipose tissue is an important predictor of complications in both non-alcoholic fatty liver disease and colonic diverticulosis. Current evidence suggests that intestinal dysbiosis may be involved in the development of both non-alcoholic fatty liver disease and colonic diverticulosis, and that metabolic syndrome is a consequence rather than a cause of this complex relationship. In this review, our aim was to assess the current knowledge of the complex interplay between metabolic syndrome, non-alcoholic fatty liver disease, and colonic diverticulosis.


Assuntos
Diverticulose Cólica , Síndrome Metabólica , Hepatopatia Gordurosa não Alcoólica , Diverticulose Cólica/diagnóstico , Humanos , Síndrome Metabólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Obesidade , Fatores de Risco
13.
Front Cell Infect Microbiol ; 11: 639667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34458156

RESUMO

Introduction: Stool consistency has been associated with fecal microbial composition. Stool consistency often varies over time, in subjects with and without gastrointestinal disorders, raising the question whether variability in the microbial composition should be considered in microbiota studies. We evaluated within-subject day-to-day variability in stool consistency and the association with the fecal microbiota in irritable bowel syndrome (IBS) and healthy subjects, over seven days. Methods: Twelve IBS patients and 12 healthy subjects collected fecal samples during seven consecutive days. Stool consistency was determined by the patient-reported Bristol Stool Scale (BSS) and fecal dry weight percentage. 16S rRNA V4 gene sequencing was performed and microbial richness (alpha diversity; Chao1 index, observed number of species, effective Shannon index) and microbial community structure (beta diversity; Bray-Curtis distance, generalized UniFrac, and taxa abundance on family level) were determined. Results: Linear mixed-effects models showed significant associations between stool consistency and microbial richness, but no time effect. This implies that between-subject but not within-subject variation in microbiota over time can partially be explained by variation in stool consistency. Redundancy analysis showed a significant association between stool consistency and microbial community structure, but additional linear mixed-effects models did not demonstrate a time effect on this. Conclusion: This study supports an association between stool consistency and fecal microbiota, but no effect of day-to-day fluctuations in stool consistency within seven days. This consolidates the importance of considering stool consistency in gut microbiota research, though confirms the validity of single fecal sampling to represent an individual's microbiota at a given time point. NCT00775060.


Assuntos
Microbioma Gastrointestinal , Síndrome do Intestino Irritável , Microbiota , Fezes , Humanos , RNA Ribossômico 16S/genética
14.
Environ Microbiol ; 12(12): 3213-27, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20626454

RESUMO

The diversity and temporal stability of the predominant bacteria in the human ileum was studied with the use of ileal effluent samples of seven individuals with Brooke ileostomies. The total number of bacteria within the ileal effluent was in the range of 107 -108 bacteria per gram (wet weight). The diversity of the bacteria in the ileal effluent showed marked differences compared with that in faecal samples from age-matched healthy adults. The ileal effluent had a higher relative abundance of species within the orders Lactobacillales and Clostridiales, mainly Streptococcus bovis-related species, and the Veillonella group, and a lower proportion of species related to Ruminococcus gnavus, R. obeum and Bacteroides plebeius. In addition, inter-individual differences were found, indicative of a highly personal ileal microbiota profile. Furthermore, temporal profiles showed large fluctuations per individual over a period of 9-28 days (average similarity over a period of 9 days was as low as 44%), and differences between morning and afternoon profiles were observed. Parallel cloning and sequencing efforts revealed several phylotypes that were not identified in previous studies (12 out of 65 phylotypes showed less than 97% sequence similarity with previously reported sequences). Achaea were found to be below detection limit by quantitative PCR. Overall, the results indicate that the microbiota of the human ileum is relatively unstable, less complex and consisting of different dominating phylotypes when compared with the colonic microbiota.


Assuntos
Bactérias/genética , Íleo/microbiologia , Metagenoma , Adulto , Idoso , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Estudos de Casos e Controles , Fezes/microbiologia , Feminino , Genes de RNAr , Humanos , Ileostomia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Fatores de Tempo
15.
Microbiology (Reading) ; 156(Pt 11): 3270-3281, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20847013

RESUMO

A high-density phylogenetic microarray targeting small subunit rRNA (SSU rRNA) sequences of over 1000 microbial phylotypes of the human gastrointestinal tract, the HITChip, was used to assess the impact of faecal inoculum preparation and operation conditions on an in vitro model of the human large intestine (TIM-2). This revealed that propagation of mixed faecal donations for the production of standardized inocula has only a limited effect on the microbiota composition, with slight changes observed mainly within the Firmicutes. Adversely, significant shifts in several major groups of intestinal microbiota were observed after inoculation of the in vitro model. Hierarchical cluster analysis was able to show that samples taken throughout the inoculum preparation grouped with microbiota profiles observed for faecal samples of healthy adults. In contrast, the TIM-2 microbiota was distinct. While members of the Bacteroidetes and some groups within the Bacilli were increased in TIM-2 microbiota, a strong reduction in the relative abundance of other microbial groups, including Bifidobacterium spp., Streptococcus spp., and Clostridium clusters IV and XIVa, was observed. The changes detected with the HITChip could be confirmed using denaturing gradient gel electrophoresis (DGGE) of SSU rRNA amplicons.


Assuntos
Bactérias/genética , Intestino Grosso/microbiologia , Metagenoma , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Subunidades Ribossômicas Menores de Bactérias/genética , Técnicas Bacteriológicas , Análise por Conglomerados , DNA Bacteriano/genética , Eletroforese em Gel de Gradiente Desnaturante , Fezes/microbiologia , Humanos , Modelos Biológicos , Filogenia
16.
Aliment Pharmacol Ther ; 51(6): 582-602, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32056247

RESUMO

BACKGROUND: Helicobacter pylori is the most infamous constituent of the gastric microbiota and its presence is the strongest risk factor for gastric cancer and other gastroduodenal diseases. Although historically the healthy stomach was considered a sterile organ, we now know it is colonised with a complex microbiota. However, its role in health and disease is not well understood. AIM: To systematically explore the literature on the gastric microbiota in health and disease as well as the gut microbiota after bariatric surgery. METHODS: A systematic search of online bibliographic databases MEDLINE/EMBASE was performed between 1966 and February 2019 with screening in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Randomised controlled trials, cohort studies and observational studies were included if they reported next-generation sequencing derived microbiota analysis on gastric aspirate/tissue or stool samples (bariatric surgical outcomes). RESULTS: Sixty-five papers were eligible for inclusion. With the exception of H pylori-induced conditions, overarching gastric microbiota signatures of health or disease could not be determined. Gastric carcinogenesis induces a progressively altered microbiota with an enrichment of oral and intestinal taxa as well as significant changes in host gastric mucin expression. Proton pump inhibitors usage increases gastric microbiota richness. Bariatric surgery is associated with an increase in potentially pathogenic proteobacterial species in patient stool samples. CONCLUSION: While H pylori remains the single most important risk factor for gastric disease, its capacity to shape the collective gastric microbiota remains to be fully elucidated. Further studies are needed to explore the intricate host/microbial and microbial/microbial interplay.


Assuntos
Mucosa Gástrica/microbiologia , Gastroenteropatias/etiologia , Microbioma Gastrointestinal/fisiologia , Saúde , Neoplasias Gástricas/etiologia , Estudos de Coortes , DNA Bacteriano/análise , Mucosa Gástrica/patologia , Gastroenteropatias/tratamento farmacológico , Gastroenteropatias/epidemiologia , Gastroenteropatias/microbiologia , Infecções por Helicobacter/complicações , Infecções por Helicobacter/epidemiologia , Helicobacter pylori/fisiologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Inibidores da Bomba de Prótons/uso terapêutico , Fatores de Risco , Análise de Sequência de DNA/métodos , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/microbiologia
17.
Environ Microbiol ; 11(7): 1736-51, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19508560

RESUMO

In this paper we present the in silico assessment of the diversity of variable regions of the small subunit ribosomal RNA (SSU rRNA) gene based on an ecosystem-specific curated database, describe a probe design procedure based on two hypervariable regions with minimal redundancy and test the potential of such probe design strategy for the design of a flexible microarray platform. This resulted in the development and application of a phylogenetic microarray for studying the human gastrointestinal microbiota--referred as the human intestinal tract chip (HITChip). Over 4800 dedicated tiling oligonucleotide probes were designed based on two hypervariable regions of the SSU rRNA gene of 1140 unique microbial phylotypes (< 98% identity) following analysis of over 16,000 human intestinal SSU rRNA sequences. These HITChip probes were hybridized to a diverse set of human intestinal samples and SSU rRNA clones to validate its fingerprinting and quantification potential. Excellent reproducibility (median Pearson's correlation of 0.99) was obtained following hybridization with T7 polymerase transcripts generated in vitro from SSU rRNA gene amplicons. A linear dose-response was observed with artificial mixtures of 40 different representative amplicons with relative abundances as low as 0.1% of total microbiota. Analysis of three consecutively collected faecal samples from ten individuals (five young and five elderly adults) revealed temporal dynamics and confirmed that the adult intestinal microbiota is an individual-specific and relatively stable ecosystem. Further analysis of the stable part allowed for the identification of a universal microbiota core at the approximate genus level (90% sequence similarity). This core consists of members of Actinobacteria, Bacteroidetes and Firmicutes. Used as a phylogenetic fingerprinting tool with the possibility for relative quantification, the HITChip has the potential to bridge the gaps in our knowledge in the quantitative and qualitative description of the human gastrointestinal microbiota composition.


Assuntos
Biodiversidade , Trato Gastrointestinal/microbiologia , Metagenoma , Análise em Microsséries/métodos , Técnicas Microbiológicas/métodos , Adulto , Idoso , DNA Ribossômico/genética , Fezes/microbiologia , Variação Genética , Humanos , Sondas de Oligonucleotídeos/genética , Reprodutibilidade dos Testes
18.
Environ Microbiol ; 11(4): 914-26, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19128319

RESUMO

Carbohydrates, including starches, are an important energy source for humans, and are known for their interactions with the microbiota in the digestive tract. Largely, those interactions are thought to promote human health. Using 16S ribosomal RNA (rRNA)-based stable isotope probing (SIP), we identified starch-fermenting bacteria under human colon-like conditions. To the microbiota of the TIM-2 in vitro model of the human colon 7.4 g l(-1) of [U-(13)C]-starch was added. RNA extracted from lumen samples after 0 (control), 2, 4 and 8 h was subjected to density-gradient ultracentrifugation. Terminal-restriction fragment length polymorphism (T-RFLP) fingerprinting and phylogenetic analyses of the labelled and unlabelled 16S rRNA suggested populations related to Ruminococcus bromii, Prevotella spp. and Eubacterium rectale to be involved in starch metabolism. Additionally, 16S rRNA related to that of Bifidobacterium adolescentis was abundant in all analysed fractions. While this might be due to the enrichment of high-GC RNA in high-density fractions, it could also indicate an active role in starch fermentation. Comparison of the T-RFLP fingerprints of experiments performed with labelled and unlabelled starch revealed Ruminococcus bromii as the primary degrader in starch fermentation in the studied model, as it was found to solely predominate in the labelled fractions. LC-MS analyses of the lumen and dialysate samples showed that, for both experiments, starch fermentation primarily yielded acetate, butyrate and propionate. Integration of molecular and metabolite data suggests metabolic cross-feeding in the system, where populations related to Ruminococcus bromii are the primary starch degrader, while those related to Prevotella spp., Bifidobacterium adolescentis and Eubacterium rectale might be further involved in the trophic chain.


Assuntos
Bactérias/classificação , Bactérias/metabolismo , Intestino Grosso/microbiologia , Amido/metabolismo , Acetatos/metabolismo , Bactérias/crescimento & desenvolvimento , Butiratos/metabolismo , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fermentação , Genes de RNAr , Humanos , Técnicas In Vitro , Isótopos/metabolismo , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , Propionatos/metabolismo , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência do Ácido Nucleico , Coloração e Rotulagem
19.
Eur J Pharm Sci ; 124: 26-36, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30130639

RESUMO

Antibiotic containing polycaprolactone (PCL) fibers were produced by using three electrospinning methods: blend, emulsion and co-axial electrospinning (labeled as S1, S2 and S3, respectively). The profiles of drug release from three different systems were studied and antimicrobial properties of produced materials were evaluated. Morphology of the produced fibers was characterized and revealed that cefazolin-loaded PCL fibers had smaller diameter compared to neat PCL fibers, while the chemical interaction between the antibiotic and PCL showed that cefazolin neither had reacted with PCL phase, nor had degraded during the electrospinning process. The crystallinity and thermal characterization of fabricated fibers showed that the addition of cefazolin decreased the crystallinity of PCL. The results of the drug release behavior of the blend and co-axial electrospun fibers was on a higher level (~68% and ~43%, respectively) compared to the emulsion electrospun fibers (~5%), after a period of 30 days. The obtained data had the best fitting with the first order model and the Higuchi model, while the Korsmeyer-Peppas model showed a Pseudo-Fickian diffusion of the drug. Antibacterial evaluations showed that cefazolin-loaded PCL fibers had better effects on Staphylococcus aureus compared to Escherichia coli during the treatment period and that the effect of the emulsion fibers was notably weaker than the other two studied systems. The aim of the study was to test different systems for control drug release of different dynamics, which will be applied for prevent bacterial accumulation when indwelling urinary catheters, applied for different periods of time.


Assuntos
Antibacterianos/química , Cefazolina/química , Nanofibras/química , Poliésteres/química , Antibacterianos/administração & dosagem , Cefazolina/administração & dosagem , Composição de Medicamentos , Liberação Controlada de Fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Nanofibras/administração & dosagem , Poliésteres/administração & dosagem , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento
20.
J Gastrointestin Liver Dis ; 27(2): 119-125, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29922755

RESUMO

BACKGROUND AND AIMS: A negative association between H. pylori and inflammatory bowel disease (IBD) has been previously reported. There were also case reports suggesting a new onset of IBD 6-12 months after H. pylori eradication therapy. In a case-control study we investigated whether previous H. pylori eradication therapy was associated with the risk of developing IBD. METHODS: IBD outpatients with both Crohn´s disease (CD) and ulcerative colitis (UC) were enrolled. Age- and sex-matched blood donors served as controls in a 1:2 fashion. Information on demographics, medical history, previous H. pylori infection and eradication therapy was recorded. Serum samples for H. pylori serology testing (anti-H. pylori-IgG and anti-CagA-IgG) were obtained. Controls that received H. pylori eradication therapy during the 12 months previous to enrollment were excluded. RESULTS: Overall, 127 IBD patients (CD N= 90; UC N=37) and 254 controls were enrolled. The prevalence of H. pylori infection (positive H. pylori serology and/or previous eradication) in IBD patients and controls was 11% and 23%, respectively (OR 0.4, 95% CI 0.21-0.74, p<0.003). Four patients (3%) developed IBD (3 MC and 1 CU) after receiving successful H. pylori eradication (latency 6-12 months). The rate of previous H. pylori eradication therapy in patents who successively developed IBD was lower but not statistically different from that observed in the control group (OR 0.43, 95% CI 0.14-1.29, p=0.16). CONCLUSIONS: In our study previous H. pylori eradication therapy was not associated with the onset of IBD. Whether in a subgroup of patients, H. pylori eradication therapy may trigger a latent IBD, cannot be excluded.


Assuntos
Infecções por Helicobacter/complicações , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/isolamento & purificação , Doenças Inflamatórias Intestinais/etiologia , Adolescente , Adulto , Idoso , Antibacterianos/uso terapêutico , Produtos Biológicos/uso terapêutico , Estudos de Casos e Controles , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/microbiologia , Doença de Crohn/tratamento farmacológico , Doença de Crohn/epidemiologia , Doença de Crohn/microbiologia , Feminino , Alemanha/epidemiologia , Infecções por Helicobacter/epidemiologia , Humanos , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/epidemiologia , Doenças Inflamatórias Intestinais/microbiologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
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