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1.
BMC Bioinformatics ; 22(1): 3, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407079

RESUMO

BACKGROUND: Hydrogen cross-feeding microbes form a functionally important subset of the human colonic microbiota. The three major hydrogenotrophic functional groups of the colon: sulphate-reducing bacteria (SRB), methanogens and reductive acetogens, have been linked to wide ranging impacts on host physiology, health and wellbeing. RESULTS: An existing mathematical model for microbial community growth and metabolism was combined with models for each of the three hydrogenotrophic functional groups. The model was further developed for application to the colonic environment via inclusion of responsive pH, host metabolite absorption and the inclusion of host mucins. Predictions of the model, using two existing metabolic parameter sets, were compared to experimental faecal culture datasets. Model accuracy varied between experiments and measured variables and was most successful in predicting the growth of high relative abundance functional groups, such as the Bacteroides, and short chain fatty acid (SCFA) production. Two versions of the colonic model were developed: one representing the colon with sequential compartments and one utilising a continuous spatial representation. When applied to the colonic environment, the model predicted pH dynamics within the ranges measured in vivo and SCFA ratios comparable to those in the literature. The continuous version of the model simulated relative abundances of microbial functional groups comparable to measured values, but predictions were sensitive to the metabolic parameter values used for each functional group. Sulphate availability was found to strongly influence hydrogenotroph activity in the continuous version of the model, correlating positively with SRB and sulphide concentration and negatively with methanogen concentration, but had no effect in the compartmentalised model version. CONCLUSIONS: Although the model predictions compared well to only some experimental measurements, the important features of the colon environment included make it a novel and useful contribution to modelling the colonic microbiota.


Assuntos
Bactérias/metabolismo , Colo , Microbioma Gastrointestinal , Hidrogênio/metabolismo , Colo/metabolismo , Colo/microbiologia , Humanos , Modelos Biológicos , Sulfetos/metabolismo
2.
Nat Commun ; 11(1): 5912, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33219235

RESUMO

The physiological homeostasis of gut mucosal barrier is maintained by both genetic and environmental factors and its impairment leads to pathogenesis such as inflammatory bowel disease. A cytokine like molecule, FAM3D (mouse Fam3D), is highly expressed in mouse gastrointestinal tract. Here, we demonstrate that deficiency in Fam3D is associated with impaired integrity of colonic mucosa, increased epithelial hyper-proliferation, reduced anti-microbial peptide production and increased sensitivity to chemically induced colitis associated with high incidence of cancer. Pretreatment of Fam3D-/- mice with antibiotics significantly reduces the severity of chemically induced colitis and wild type (WT) mice co-housed with Fam3D-/- mice phenocopy Fam3D-deficiency showing increased sensitivity to colitis and skewed composition of fecal microbiota. An initial equilibrium of microbiota in cohoused WT and Fam3D-/- mice is followed by an increasing divergence of the bacterial composition after separation. These results demonstrate the essential role of Fam3D in colon homeostasis, protection against inflammation associated cancer and normal microbiota composition.


Assuntos
Carcinogênese , Colo , Citocinas/metabolismo , Animais , Colite , Colo/metabolismo , Colo/microbiologia , Colo/patologia , Neoplasias Colorretais , Modelos Animais de Doenças , Microbioma Gastrointestinal , Inflamação , Doenças Inflamatórias Intestinais , Mucosa Intestinal/crescimento & desenvolvimento , Mucosa Intestinal/patologia , Camundongos , Proteínas Citotóxicas Formadoras de Poros/metabolismo
3.
Exp Parasitol ; 219: 108030, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33080305

RESUMO

The gut microbiota has been demonstrated to associate with protection against helminth infection and mediate via microbial effects on the host humoral immunity. As a non-permissive host of Schistosoma japonicum, the Microtus fortis provides an ideal animal model to be investigated, because of its natural self-healing capability. Although researches on the systemic immunological responses have revealed that the host immune system contributes a lot to the resistance, the role of gut microbiome remains unclear. In this study, we exposed the M. fortis to the S.japonicum infection, carried out a longitudinal research (uninfected control, infected for 7 days, 14 days, 21 days, and 31 days) on their colonic microbiota based on the 16S rRNA gene amplicon sequencing. The bacterial composition disclosed a disturbance-recovery alteration followed by the resistance to S. japonicum. The alpha diversity of colon microbiota was reduced after the infection, but it gradually recovered along with self-healing process. Further LEfSe analysis revealed that phyla shifted from Firmicutes to Bacteroidetes, which were mainly driven by an increase of Ruminococcaceae and a depletion of Muribaculaceae in the family level along the Control-Infection-Recovery (CIR) process. We identified a temporary blooming of Lactobacillaceae and Lactobacillus in the mid infection stage (D14). As a recognized probiotics repository, we speculate the increased abundance of Lactobacillaceae in M. fortis colonic microbiota might relate to the natural resistance to the schistosome. Besides, potential microbial functions were also significantly changed in the resistance process. These results demonstrate the remarkable alterations of reed vole colonic microbiota in both community structure and potential functions along with the resistance to S. japonicum infection. The identified microbial biomarkers might offer new ways for drug development to conquer human schistosomiasis.


Assuntos
Colo/microbiologia , Microbioma Gastrointestinal , Schistosoma japonicum/imunologia , Esquistossomose Japônica/imunologia , Animais , Arvicolinae , Bacteroidetes/crescimento & desenvolvimento , Biomarcadores , Análise Discriminante , Modelos Animais de Doenças , Resistência à Doença , Firmicutes/crescimento & desenvolvimento , Estudos Longitudinais , Masculino
4.
Science ; 370(6515): 467-472, 2020 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-33093110

RESUMO

Colon mucus segregates the intestinal microbiota from host tissues, but how it organizes to function throughout the colon is unclear. In mice, we found that colon mucus consists of two distinct O-glycosylated entities of Muc2: a major form produced by the proximal colon, which encapsulates the fecal material including the microbiota, and a minor form derived from the distal colon, which adheres to the major form. The microbiota directs its own encapsulation by inducing Muc2 production from proximal colon goblet cells. In turn, O-glycans on proximal colon-derived Muc2 modulate the structure and function of the microbiota as well as transcription in the colon mucosa. Our work shows how proximal colon control of mucin production is an important element in the regulation of host-microbiota symbiosis.


Assuntos
Colo/metabolismo , Colo/microbiologia , Microbioma Gastrointestinal , Mucina-2/metabolismo , Muco/metabolismo , Animais , Fezes/microbiologia , Glicosilação , Camundongos , Camundongos Knockout , Mucina-2/genética , Transcrição Genética
6.
PLoS One ; 15(9): e0239681, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991615

RESUMO

Cellular homeostasis of zinc, an essential element for living organisms, is tightly regulated by a family of zinc transporters. The zinc transporter 7, ZnT7, is highly expressed on the membrane of the Golgi complex of intestinal epithelial cells and goblet cells. It has previously been shown that Znt7 knockout leads to zinc deficiency and decreased weight gain in C57BL/6 mice on a defined diet. However, effects within the colon are unknown. Given the expression profile of Znt7, we set out to analyze the changes in mucin density and gut microbial composition in the mouse large intestine induced by Znt7 knockout. We fed a semi-purified diet containing 30 mg Zn/kg to Znt7-/- mice with their heterozygous and wild type littermates and found a sex specific effect on colonic mucin density, goblet cell number, and microbiome composition. In male mice Znt7 knockout led to increased goblet cell number and mucin density but had little effect on gut microbiome composition. However, in female mice Znt7 knockout was associated with decreased goblet cell number and mucin density, with increased proportions of the microbial taxa, Allobaculum, relative to wild type. The gut microbial composition was correlated with mucin density in both sexes. These findings suggest that a sex-specific relationship exists between zinc homeostasis, mucin production and the microbial community composition within the colon.


Assuntos
Proteínas de Transporte de Cátions/genética , Colo/metabolismo , Microbioma Gastrointestinal , Células Caliciformes/citologia , Animais , Peso Corporal , Proteínas de Transporte de Cátions/deficiência , Proteínas de Transporte de Cátions/metabolismo , Colo/microbiologia , Colo/patologia , Dieta , Feminino , Células Caliciformes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mucinas/metabolismo , Análise de Componente Principal , RNA Mensageiro/metabolismo , Zinco/metabolismo
7.
Ecotoxicol Environ Saf ; 203: 111041, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888612

RESUMO

Although the production and use of PCB153 have been banned globally, PCB153 pollution remains because of its persistence and long half-life in the environment. There is ongoing evidence that exposure to PCB153 may influence gut microbiota health and increase the risk of host health. It is needed to illuminate whether there are associations between gut microbiota dysregulation and PCB153-induced host diseases. Importantly, it is urgently needed to find specific strains as biomarkers to monitor PCB153 pollution and associated disorders. The work aims to investigate the change of gut microbiota composition, structure and diversity and various host physiological indexes, to ravel the chain causality of PCB153, gut microbiota health and host health, and to find potential gut microbiota markers for PCB153 pollution. Here, adult female mice were administrated with PCB153. Obtained results indicated that PCB153 led to gut microbiota health deterioration. PCB153 exposure also induced obesity, hepatic lipid accumulation, abdominal adipose tissue depots and dyslipidemia in mice. Furthermore, specific gut microbiota significantly correlated with the host health indexes. This work provides support for the relationship between gut microbiota aberrance derived from PCB153 and risk of host health, and offers some indications of possible indicative functions of gut microbiota on PCB153 pollution.


Assuntos
Dislipidemias/induzido quimicamente , Monitoramento Ambiental/métodos , Poluentes Ambientais/toxicidade , Microbioma Gastrointestinal/efeitos dos fármacos , Obesidade/induzido quimicamente , Bifenilos Policlorados/toxicidade , Animais , Biomarcadores/análise , Colo/microbiologia , Dislipidemias/metabolismo , Dislipidemias/microbiologia , Feminino , Conteúdo Gastrointestinal/microbiologia , Microbioma Gastrointestinal/genética , Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo , Obesidade/microbiologia , RNA Ribossômico 16S
8.
PLoS Negl Trop Dis ; 14(9): e0008667, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32986710

RESUMO

Digestive and cardiodigestive forms of Chagas' disease are observed in 2% to 27% of the patients, depending on their geographic location, Trypanosoma cruzi strain and immunopathological responses. The aim of this work was to evaluate the role of NOD2 innate immune receptor in the pathogenesis of the digestive system in Chagas' disease. Patients with digestive form of the disease showed lower mRNA expression of NOD2, higher expression of RIP2 and α-defensin 6, compared to indeterminate form, detected by Real-time PCR in peripheral blood mononuclear cells. In addition, there was a negative correlation between the expression of NOD2 and the degree of dilation of the esophagus, sigmoid and rectum in those patients. The infection of NOD2-/- mice with T. cruzi strain isolated from the digestive patient induced a decrease in intestinal motility. Histopathological analysis of the colon and jejunum of NOD2-/- and wild type C57BL/6 animals revealed discrete inflammatory foci during the acute phase of infection. Interestingly, during the chronic phase of the infection there was inflammation and hypertrophy of the longitudinal and circular muscular layer more pronounced in the colon and jejunum from NOD2-/- animals, when compared to wild type C57BL/6 mice. Together, our results suggest that NOD2 plays a protective role against the development of digestive form of Chagas' disease.


Assuntos
Doença de Chagas/imunologia , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/imunologia , Proteína Adaptadora de Sinalização NOD2/metabolismo , Trypanosoma cruzi/imunologia , Adolescente , Adulto , Idoso , Animais , Brasil , Doença de Chagas/patologia , Colo/microbiologia , Colo/patologia , Modelos Animais de Doenças , Feminino , Humanos , Imunidade Inata , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/genética , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismo , Adulto Jovem , alfa-Defensinas/genética , alfa-Defensinas/metabolismo
9.
Nat Commun ; 11(1): 4766, 2020 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-32958778

RESUMO

Germline telomere maintenance defects are associated with an increased incidence of inflammatory diseases in humans, yet whether and how telomere dysfunction causes inflammation are not known. Here, we show that telomere dysfunction drives pATM/c-ABL-mediated activation of the YAP1 transcription factor, up-regulating the major pro-inflammatory factor, pro-IL-18. The colonic microbiome stimulates cytosolic receptors activating caspase-1 which cleaves pro-IL-18 into mature IL-18, leading to recruitment of interferon (IFN)-γ-secreting T cells and intestinal inflammation. Correspondingly, patients with germline telomere maintenance defects exhibit DNA damage (γH2AX) signaling together with elevated YAP1 and IL-18 expression. In mice with telomere dysfunction, telomerase reactivation in the intestinal epithelium or pharmacological inhibition of ATM, YAP1, or caspase-1 as well as antibiotic treatment, dramatically reduces IL-18 and intestinal inflammation. Thus, telomere dysfunction-induced activation of the ATM-YAP1-pro-IL-18 pathway in epithelium is a key instigator of tissue inflammation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ciclo Celular/metabolismo , Inflamação/patologia , Telômero/patologia , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Antibacterianos/uso terapêutico , Proteínas Mutadas de Ataxia Telangiectasia/antagonistas & inibidores , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Caspase 1/metabolismo , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Criança , Colo/metabolismo , Colo/microbiologia , Colo/patologia , Gastroenteropatias/patologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbioma Gastrointestinal/fisiologia , Humanos , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/microbiologia , Interleucina-18/genética , Interleucina-18/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Camundongos , Camundongos Mutantes , Fosforilação , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , Transdução de Sinais , Telomerase/genética , Telomerase/metabolismo
11.
Am J Physiol Gastrointest Liver Physiol ; 319(4): G421-G431, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32755385

RESUMO

The loss of the intestinal Na+/H+ exchanger isoform 8 (NHE8) results in an ulcerative colitis-like condition with reduction of mucin production and dysbiosis, indicating that NHE8 plays an important role in intestinal mucosal protection. The aim of this study was to investigate the potential rebalance of the altered microbiota community of NHE8-deficient mice via fecal microbiota transplantation (FMT) and feeding probiotic VSL#3. We also aimed to stimulate mucin production by sodium butyrate administration via enema. Data from 16S rRNA sequencing showed that loss of NHE8 contributes to colonic microbial dysbiosis with reduction of butyrate-producing bacteria. FMT increased bacterial adhesion in the colon in NHE8 knockout (NHE8KO) mice. Periodic-acid Schiff reagent (PAS) stain and quantitative PCR showed no changes in mucin production during FMT. In mice treated with the probiotic VSL#3, a reduction of Lactobacillus and segmented filamentous bacteria (SFB) in NHE8KO mouse colon was detected and an increase in goblet cell theca was observed. In NHE8KO mice receiving sodium butyrate (NaB), 1 mM NaB stimulated Muc2 expression without changing goblet cell theca, but 10 mM NaB induced a significant reduction of goblet cell theca without altering Muc2 expression. Furthermore, 5 mM and 10 mM NaB-treated HT29-MTX cells displayed increased apoptosis, while 0.5 mM NaB stimulated Muc2 gene expression. These data showed that loss of NHE8 leads to dysbiosis with reduction of butyrate-producing bacteria and FMT and VSL#3 failed to rebalance the microbiota in NHE8KO mice. Therefore, FMT, VSL#3, and NaB are not able to restore mucin production in the absence of NHE8 in the intestine.NEW & NOTEWORTHY Loss of Na+/H+ exchanger isoform 8 (NHE8), a Slc9 family of exchanger that contributes to sodium uptake, cell volume regulation, and intracellular pH homeostasis, resulted in dysbiosis with reduction of butyrate-producing bacteria and decrease of Muc2 production in the intestine in mice. Introducing fecal microbiota transplantation (FMT) and VSL#3 in NHE8 knockout (NHE8KO) mice failed to rebalance the microbiota in these mice. Furthermore, administration of FMT, VSL#3, and sodium butyrate was unable to restore mucin production in the absence of NHE8 in the intestine.


Assuntos
Mucosa Intestinal/fisiologia , Trocadores de Sódio-Hidrogênio/fisiologia , Animais , Butiratos/metabolismo , Ácido Butírico/administração & dosagem , Colo/microbiologia , Disbiose/etiologia , Disbiose/microbiologia , Disbiose/terapia , Transplante de Microbiota Fecal , Microbioma Gastrointestinal/fisiologia , Células Caliciformes/efeitos dos fármacos , Células Caliciformes/fisiologia , Células HT29 , Humanos , Lactobacillus/fisiologia , Camundongos , Camundongos Knockout , Mucinas/biossíntese , Probióticos/administração & dosagem , Trocadores de Sódio-Hidrogênio/deficiência
12.
Appl Environ Microbiol ; 86(20)2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32801170

RESUMO

Differences in individual host responses have emerged as an issue regarding the health benefits of probiotics. Here, we applied ribosome engineering (RE) technology, developed in an actinomycete study, to Lacticaseibacillus rhamnosus GG (LGG). RE can effectively enhance microbial potential by using antibiotics to induce spontaneous mutations in the ribosome and/or RNA polymerase. In this study, we identified eight types of streptomycin resistance mutations in the LGG rpsL gene, which encodes ribosomal protein S12. Notably, LGG harboring the K56N mutant (LGG-MTK56N) expressed high levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) on the cell surface compared with the LGG wild type (LGG-WT). GAPDH plays a key role in colonic mucin adhesion. Indeed, LGG-MTK56N significantly increased type A human colonic mucin adhesion compared to LGG-WT in experiments using the Biacore system. The ability to adhere to the colon is an important property of probiotics; thus, these results suggest that RE is an effective breeding strategy for probiotic lactic acid bacteria.IMPORTANCE We sought to apply ribosome engineering (RE) to probiotic lactic acid bacteria and to verify RE's impact. Here, we showed that one mutant of RE Lacticaseibacillus rhamnosus GG (LGG-MTK56N) bore a GAPDH on the cell surface; the GAPDH was exported via an ABC transporter. Compared to the wild-type parent, LGG-MTK56N adhered more strongly to human colonic mucin and exhibited a distinct cell size and shape. These findings demonstrate that RE in LGG-MTK56N yielded dramatic changes in protein synthesis, protein transport, and cell morphology and affected adherence to human colonic mucin.


Assuntos
Aderência Bacteriana/genética , Proteínas de Bactérias/genética , Gliceraldeído-3-Fosfato Desidrogenases/genética , Lactobacillus rhamnosus/genética , Mucinas/fisiologia , Ribossomos/metabolismo , Proteínas de Bactérias/metabolismo , Bioengenharia , Colo/microbiologia , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Humanos , Lactobacillus rhamnosus/enzimologia
13.
PLoS One ; 15(8): e0237108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750076

RESUMO

Anatomically terminal parts of the urinary, reproductive, and digestive systems of birds all connect to the cloaca. As the feces drain through the cloaca in chickens, the cloacal bacteria were previously believed to represent those of the digestive system. To investigate similarities between the cloacal microbiota and the microbiota of the digestive and reproductive systems, microbiota inhabiting the colon, cloaca, and magnum, which is a portion of the chicken oviduct of 34-week-old, specific-pathogen-free hens were analyzed using a 16S rRNA metagenomic approach using the Ion torrent sequencer and the Qiime2 bioinformatics platform. Beta diversity via unweighted and weighted unifrac analyses revealed that the cloacal microbiota was significantly different from those in the colon and the magnum. Unweighted unifrac revealed that the cloacal microbiota was distal from the microbiota in the colon than from the microbiota in the magnum, whereas weighted unifrac revealed that the cloacal microbiota was located further away from the microbiota in the magnum than from the microbiota inhabiting the colon. Pseudomonas spp. were the most abundant in the cloaca, whereas Lactobacillus spp. and Flavobacterium spp. were the most abundant species in the colon and the magnum. The present results indicate that the cloaca contains a mixed population of bacteria, derived from the reproductive, urinary, and digestive systems, particularly in egg-laying hens. Therefore, sampling cloaca to study bacterial populations that inhabit the digestive system of chickens requires caution especially when applied to egg-laying hens. To further understand the physiological role of the microbiota in chicken cloaca, exploratory studies of the chicken's cloacal microbiota should be performed using chickens of different ages and types.


Assuntos
Galinhas/microbiologia , Cloaca/microbiologia , Colo/microbiologia , Microbioma Gastrointestinal , Oviductos/microbiologia , Animais , Feminino , Flavobacterium/genética , Flavobacterium/patogenicidade , Lactobacillus/genética , Lactobacillus/patogenicidade , Metagenoma , Pseudomonas/genética , Pseudomonas/patogenicidade
14.
PLoS One ; 15(8): e0238006, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857814

RESUMO

This study aimed to evaluate the effects of two prebiotics in different concentrations on nutrient digestibility, fermentative products and immunological variables in adult dogs. Twenty-four adult dogs were randomly divided into six blocks according to their metabolic body weights (BW0.75); within these groups, dogs were randomized to four treatments: control without prebiotics (CO); inclusion of 0.5% prebiotic blend Yes-Golf (B1); inclusion of 1.0% galactooligosaccharide (GOS); and inclusion of 1.0% prebiotic blend Yes-Golf (B2). The experiment lasted 30 days, with 20 days adaptation and 10 days stool and blood collection. Results were analyzed for normality and means were separated by ANOVA and adjusted by the Tukey test at the significance level of 5.0%. Prebiotic supplementation had no effect on apparent digestibility coefficients (ADC), total stool production and fecal scores (p > 0.05). Prebiotics evaluated also did not alter fecal pH, nor the concentrations of ammonia, lactic acid, short chain fatty acids (SCFA) and most fecal branched chain fatty acids (BCFA) (p > 0.05). The addition of GOS decreased the concentration of iso-valeric acid (p = 0.0423). Regarding immunological variables, concentrations of fecal IgA were not influenced by the treatments. Treatments GOS and B2 increased the total number of polymorphonuclear cells, as well as the oxidative burst in relation to treatments B1 and CO (p < 0.0001). Treatment B2 improved the rate of S. aureus phagocytosis in relation to CO (p = 0.0111), and both the GOS and B2 treatments had a better index for E. coli phagocytosis than the CO treatment (p = 0.0067). In conclusion, there was indication that both prebiotics GOS and B2 at 1.0% inclusion improved the immunity of healthy dogs.


Assuntos
Colo/efeitos dos fármacos , Oligossacarídeos/farmacologia , Prebióticos , Animais , Colo/imunologia , Colo/microbiologia , Dieta/veterinária , Cães , Ácidos Graxos Voláteis/análise , Fezes/química , Microbioma Gastrointestinal/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Fagocitose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Staphylococcus aureus/fisiologia
15.
Proc Natl Acad Sci U S A ; 117(35): 21536-21545, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817490

RESUMO

The building evidence for the contribution of microbiota to human disease has spurred an effort to develop therapies that target the gut microbiota. This is particularly evident in inflammatory bowel diseases (IBDs), where clinical trials of fecal microbiota transplantation have shown some efficacy. To aid the development of novel microbiota-targeted therapies and to better understand the biology underpinning such treatments, we have used gnotobiotic mice to model microbiota manipulations in the context of microbiotas from humans with inflammatory bowel disease. Mice colonized with IBD donor-derived microbiotas exhibit a stereotypical set of phenotypes, characterized by abundant mucosal Th17 cells, a deficit in the tolerogenic RORγt+ regulatory T (Treg) cell subset, and susceptibility to disease in colitis models. Transplanting healthy donor-derived microbiotas into mice colonized with human IBD microbiotas led to induction of RORγt+ Treg cells, which was associated with an increase in the density of the microbiotas following transplant. Microbiota transplant reduced gut Th17 cells in mice colonized with a microbiota from a donor with Crohn's disease. By culturing strains from this microbiota and screening them in vivo, we identified a specific strain that potently induces Th17 cells. Microbiota transplants reduced the relative abundance of this strain in the gut microbiota, which was correlated with a reduction in Th17 cells and protection from colitis.


Assuntos
Transplante de Microbiota Fecal , Doenças Inflamatórias Intestinais/microbiologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Animais , Colite/prevenção & controle , Colo/microbiologia , Doença de Crohn/metabolismo , Doença de Crohn/microbiologia , Citocinas/imunologia , Modelos Animais de Doenças , Fezes/microbiologia , Feminino , Microbioma Gastrointestinal/imunologia , Humanos , Doenças Inflamatórias Intestinais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/microbiologia , Células Th17/microbiologia
16.
Appl Environ Microbiol ; 86(21)2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32859592

RESUMO

Salmonella enterica serovar Typhimurium is a prevalent incitant of enteritis in human beings and nonhuman animals. It has been proposed that host defense responses incited by Salmonella allow the bacterium to overcome colonization resistance. Piglets (n = 24) were orally inoculated with S. enterica serovar Typhimurium DT104 or buffer alone, and the host and microbial responses were temporally examined at the acute (2 days postinoculation [dpi]), subacute (6 dpi), and recovery (10 dpi) stages of salmonellosis. At the acute stage of disease, body temperatures were elevated, and feed consumption and weight gain were reduced. The densities of Salmonella associated with the gut mucosa decreased over time, with higher densities of the bacterium in the ileum and the large intestine. Moreover, substantive histopathological changes were observed as a function of time, with prominent epithelial injury and neutrophil infiltration observed at 2 dpi. Correspondingly, a variety of host metrics were temporally affected in piglets with salmonellosis (e.g., TNFα, IFNγ, PR39, ßD2, iNOS, IL8, REGIIIγ). The enteric microbiota was characterized using culture-independent and -dependent methods in concert, and taxon- and location-specific changes to the microbiota were observed in infected piglets. Bacteroides spp. (e.g., Bacteroides uniformis, Bacteroides fragilis), Streptococcus spp. (e.g., Streptococcus gallolyticus), and various Gammaproteobacteria were highly associated with inflamed tissues, while bacteria within the Ruminococcaceae and Veillonellaceae families were mainly associated with healthy mucosae. In conclusion, the study findings showed that S Typhimurium incited temporal and spatial modifications to the swine autochthonous microbiota, and to host defense responses, that were consistent with overcoming colonization resistance to incite salmonellosis in swine.IMPORTANCE Limited information is available on host and enteric microbiota responses incited by Salmonella enterica serovar Typhimurium in swine and on possible mechanisms by which the bacterium overcomes colonization resistance to incite salmonellosis. Temporal characterization of a variety of host metrics in piglets (e.g., physiological, histopathological, and immunological) showed the importance of studying the progression of salmonellosis. A number of host responses integrally associated with disease development were identified. Utilization of next-generation sequence analysis to characterize the enteric microbiota was found to lack sufficient resolution; however, culture-dependent and -independent methods in combination identified taxon- and location-specific changes to bacterial communities in infected piglets. The study identified bacterial and host responses associated with salmonellosis, which will be beneficial in understanding colonization resistance and in the development of effective alternatives to antibiotics to mitigate salmonellosis.


Assuntos
Ceco/microbiologia , Colo/microbiologia , Microbioma Gastrointestinal , Interações entre Hospedeiro e Microrganismos/imunologia , Íleo/microbiologia , Salmonella typhimurium/fisiologia , Animais , Ceco/imunologia , Colo/imunologia , Íleo/imunologia , Masculino , Distribuição Aleatória , Salmonelose Animal/imunologia , Salmonelose Animal/microbiologia , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Fatores de Tempo
17.
PLoS One ; 15(7): e0236199, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673355

RESUMO

Antimicrobial-resistant and novel pathogens continue to emerge, outpacing efforts to contain and treat them. Therefore, there is a crucial need for safe and effective therapies. Ultraviolet-A (UVA) phototherapy is FDA-approved for several dermatological diseases but not for internal applications. We investigated UVA effects on human cells in vitro, mouse colonic tissue in vivo, and UVA efficacy against bacteria, yeast, coxsackievirus group B and coronavirus-229E. Several pathogens and virally transfected human cells were exposed to a series of specific UVA exposure regimens. HeLa, alveolar and primary human tracheal epithelial cell viability was assessed after UVA exposure, and 8-Oxo-2'-deoxyguanosine was measured as an oxidative DNA damage marker. Furthermore, wild-type mice were exposed to intracolonic UVA as an in vivo model to assess safety of internal UVA exposure. Controlled UVA exposure yielded significant reductions in Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, Clostridioides difficile, Streptococcus pyogenes, Staphylococcus epidermidis, Proteus mirabilis and Candida albicans. UVA-treated coxsackievirus-transfected HeLa cells exhibited significantly increased cell survival compared to controls. UVA-treated coronavirus-229E-transfected tracheal cells exhibited significant coronavirus spike protein reduction, increased mitochondrial antiviral-signaling protein and decreased coronavirus-229E-induced cell death. Specific controlled UVA exposure had no significant effect on growth or 8-Oxo-2'-deoxyguanosine levels in three types of human cells. Single or repeated in vivo intraluminal UVA exposure produced no discernible endoscopic, histologic or dysplastic changes in mice. These findings suggest that, under specific conditions, UVA reduces various pathogens including coronavirus-229E, and may provide a safe and effective treatment for infectious diseases of internal viscera. Clinical studies are warranted to further elucidate the safety and efficacy of UVA in humans.


Assuntos
Infecções Bacterianas/terapia , Micoses/terapia , Infecções Oportunistas/terapia , Terapia Ultravioleta/métodos , Viroses/terapia , Animais , Apoptose/efeitos da radiação , Bactérias/efeitos da radiação , Infecções Bacterianas/microbiologia , Sobrevivência Celular/efeitos da radiação , Colo/microbiologia , Colo/efeitos da radiação , Coronavirus Humano 229E/efeitos da radiação , Dano ao DNA/efeitos da radiação , Modelos Animais de Doenças , Enterovirus Humano B/efeitos da radiação , Feminino , Células HeLa , Humanos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/efeitos da radiação , Masculino , Camundongos , Micoses/microbiologia , Infecções Oportunistas/microbiologia , Cultura Primária de Células , Terapia Ultravioleta/efeitos adversos , Viroses/virologia , Leveduras/efeitos da radiação
19.
PLoS One ; 15(7): e0236106, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32673362

RESUMO

Alfalfa is a forage legume commonly associated with ruminant livestock production that may be a potential source of health-promoting phytochemicals. Anecdotal evidence from producers suggests that later cuttings of alfalfa may be more beneficial to non-ruminants; however, published literature varies greatly in measured outcomes, supplement form, and cutting. The objective of this study was to measure body weight, average daily feed intake, host immunity, and the colon microbiota composition in mice fed hay, aqueous, and chloroform extracts of early (1st) and late (5th) cutting alfalfa before and after challenge with Citrobacter rodentium. Prior to inoculation, alfalfa supplementation did not have a significant impact on body weight or feed intake, but 5th cutting alfalfa was shown to improve body weight at 5- and 6-days post-infection compared to 1st cutting alfalfa (P = 0.02 and 0.01). Combined with the observation that both chloroform extracts improved mouse body weight compared to control diets in later stages of C. rodentium infection led to detailed analyses of the immune system and colon microbiota in mice fed 1st and 5th cutting chloroform extracts. Immediately following inoculation, 5th cutting chloroform extracts significantly reduced the relative abundance of C. rodentium (P = 0.02) and did not display the early lymphocyte recruitment observed in 1st cutting extract. In later timepoints, both chloroform extracts maintained lower splenic B-cell and macrophage populations while increasing the relative abundance of potentially beneficially genera such as Turicibacter (P = 0.02). At 21dpi, only 5th cutting chloroform extracts increased the relative abundance of beneficial Akkermansia compared to the control diet (P = 0.02). These results suggest that lipid soluble compounds enriched in late-cutting alfalfa modulate pathogen colonization and early immune responses to Citrobacter rodentium, contributing to protective effects on body weight.


Assuntos
Citrobacter rodentium/fisiologia , Colo/efeitos dos fármacos , Infecções por Enterobacteriaceae/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Lipídeos/química , Medicago sativa/química , Extratos Vegetais/farmacologia , Imunidade Adaptativa/efeitos dos fármacos , Animais , Peso Corporal/efeitos dos fármacos , Colo/microbiologia , Citocinas/biossíntese , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/metabolismo , Infecções por Enterobacteriaceae/microbiologia , Feminino , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Interações Hospedeiro-Patógeno/imunologia , Imunidade Inata/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/uso terapêutico , Solubilidade
20.
PLoS One ; 15(7): e0235985, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32678865

RESUMO

Chronic constipation (CC) is one of the most common gastrointestinal disorders worldwide. Its pathogenesis, however, remains largely unclear. The purpose of the present work was to gain an insight into the role of contractility and microbiota in the etiology of CC. To this end, we studied spontaneous and evoked contractile activity of descending colon segments from patients that have undergone surgery for refractory forms of CC. The juxta-mucosal microbiota of these colon samples were characterized with culture-based and 16S rRNA sequencing techniques. In patients with CC the spontaneous colonic motility remained unchanged compared to the control group without dysfunction of intestinal motility. Moreover, contractions induced by potassium chloride and carbachol were increased in both circular and longitudinal colonic muscle strips, thus indicating preservation of contractile apparatus and increased sensitivity to cholinergic nerve stimulation in the constipated intestine. In the test group, the gut microbiota composition was assessed as being typically human, with four dominant bacterial phyla, namely Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria, as well as usual representation of the most prevalent gut bacterial genera. Yet, significant inter-individual differences were revealed. The phylogenetic diversity of gut microbiota was not affected by age, sex, or colonic anatomy (dolichocolon, megacolon). The abundance of butyrate-producing genera Roseburia, Coprococcus, and Faecalibacterium was low, whereas conventional probiotic genera Lactobacillus and Bifidobacteria were not decreased in the gut microbiomes of the constipated patients. As evidenced by our study, specific microbial biomarkers for constipation state are absent. The results point to a probable role played by the overall gut microbiota at the functional level. To our knowledge, this is the first comprehensive characterization of CC pathogenesis, finding lack of disruption of motor activity of colonic smooth muscle cells and insufficiency of particular members of gut microbiota usually implicated in CC.


Assuntos
Colo/microbiologia , Colo/fisiopatologia , Constipação Intestinal/microbiologia , Constipação Intestinal/fisiopatologia , Microbioma Gastrointestinal , Contração Muscular , Adulto , Idoso , Doença Crônica , Classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
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