Enteric Microbiota Research Articles

Enumeração de microrganismos causadores da mastite bovina e estudo da ação de antimicrobianos

1024x768 Mastitis is an inflammation of the mammary gland caused mainly by microorganisms, altering the characteristics of milk and results in significant economic losses for this production complex. The study aimed to determine the main causative agents of bovine mastitis in a dairy farm in Rio Pomba city, Minas Gerais state, Brazil, and evaluate the use of plant extract and antibiotics commonly used in the control of microorganisms that cause this disease. Raw milk samples coming from 47 dairy cow were individually collected for microbiological evaluation. We also evaluated the sensitivity of isolates from the plant extract and the antibiotics commonly used in the farm. It was found that 17.0 %, 31.9 %, 85.4 % and 38.3 % of the samples presented, respectively, Staphylococcus aureus , coliforms, faecal coliforms and Escherichia coli. Furthermore, most of the samples showed counts of aerobic mesophilic microorganisms and Streptococcus sp. between 10 4 and 10 5 CFU.mL -1 , while the counts of S. aureus ranged between 10 2 and 10 3 CFU.mL -1 in most of samples. A higher efficacy of tetracycline on the isolates of S. aureus was verified and of ampicillin on the E. coli isolates. All isolates of the latter bacteria were resistant to plant extract. Due to the high incidence of microorganisms, we emphasize the need for implementation of Good Agricultural Practices in milk production, because these bacteria are coming from hair, skin, mucous membranes of animals and/or belonging to the enteric microbiota of mammals, respectively. Normal 0 21 false false false PT-BR X-NONE X-NONE st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabela normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Calibri,sans-serif;}

Norovirus Triggered Microbiota-driven Mucosal Inflammation in Interleukin 10-deficient Mice

Infection may trigger clinically overt mucosal inflammation in patients with predisposition for inflammatory bowel disease. However, the impact of particular enteropathogenic microorganisms is ill-defined. In this study, the influence of murine norovirus (MNV) infection on clinical, histopathological, and immunological features of mucosal inflammation in the IL10-deficient (Il10) mouse model of inflammatory bowel disease was examined. C57BL/6J and C3H/HeJBir wild-type and Il10 mice kept under special pathogen-free conditions and devoid of clinical and histopathological signs of mucosal inflammation were monitored after MNV infection for structural and functional intestinal barrier changes by in situ MNV reverse transcription PCR, transgene reporter gene technology, histology, flux measurements, quantitative real-time PCR, immunohistology, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay. In addition, the influence of the enteric microbiota was analyzed in MNV-infected germfree Il10 mice. Although MNV-infected wild-type mice remained asymptomatic, mucosal inflammation was noted in previously healthy Il10 mice 2 to 4 weeks after infection. MNV-induced changes in Il10 mice included increased paracellular permeability indicated by increased mucosal mannitol flux, reduced gene expression of tight junction molecules, and an enhanced rate of epithelial apoptosis. MNV-induced reduction of tight junction protein expression and inflammatory lesions were absent in germfree Il10 mice, whereas epithelial apoptosis was still observed. Despite its subclinical course in wild-type animals, MNV causes epithelial barrier disruption in Il10 animals representing a potent colitogenic stimulus that largely depends on the presence of the enteric microbiota. MNV might thus trigger overt clinical disease in individuals with a nonsymptomatic predisposition for inflammatory bowel disease by impairment of the intestinal mucosa.

Heat Shock Proteins: Intestinal Gatekeepers that Are Influenced by Dietary Components and the Gut Microbiota.

Trillions of microorganisms that inhabit the intestinal tract form a diverse and intricate ecosystem with a deeply embedded symbiotic relationship with their hosts. As more detailed information on gut microbiota complexity and functional diversity accumulates, we are learning more about how diet-microbiota interactions can influence the immune system within and outside the gut and host health in general. Heat shock proteins are a set of highly conserved proteins that are present in all types of cells, from microbes to mammals. These proteins carry out crucial intracellular housekeeping functions and unexpected extracellular immuno-regulatory features in order to maintain the mucosal barrier integrity and gut homeostasis. It is becoming evident that the enteric microbiota is one of the major determinants of heat shock protein production in intestinal epithelial cells. This review will focus on the interactions between diet, gut microbiota and their role for regulating heat shock protein production and, furthermore, how these interactions influence the immune system and the integrity of the mucosal barrier.

Helminth co-infection in Helicobacter pylori infected INS-GAS mice attenuates gastric premalignant lesions of epithelial dysplasia and glandular atrophy and preserves colonization resistance of the stomach to lower bowel microbiota

Higher prevalence of helminth infections in Helicobacter pylori infected children was suggested to potentially lower the life-time risk for gastric adenocarcinoma. In rodent models, helminth co-infection does not reduce Helicobacter-induced inflammation but delays progression of pre-malignant gastric lesions. Because gastric cancer in INS-GAS mice is promoted by intestinal microflora, the impact of Heligmosomoides polygyrus co-infection on H. pylori-associated gastric lesions and microflora were evaluated. Male INS-GAS mice co-infected with H. pylori and H. polygyrus for 5 months were assessed for gastrointestinal lesions, inflammation-related mRNA expression, FoxP3+ cells, epithelial proliferation, and gastric colonization with H. pylori and Altered Schaedler Flora. Despite similar gastric inflammation and high levels of proinflammatory mRNA, helminth co-infection increased FoxP3+ cells in the corpus and reduced H. pylori-associated gastric atrophy (p < 0.04), dysplasia (p < 0.02) and prevented H. pylori-induced changes in the gastric flora (p < 0.05). This is the first evidence of helminth infection reducing H. pylori-induced gastric lesions while inhibiting changes in gastric flora, consistent with prior observations that gastric colonization with enteric microbiota accelerated gastric lesions in INS-GAS mice. Identifying how helminths reduce gastric premalignant lesions and impact bacterial colonization of the H. pylori infected stomach could lead to new treatment strategies to inhibit progression from chronic gastritis to cancer in humans.

Enteric microbiota leads to new therapeutic strategies for ulcerative colitis.

Ulcerative colitis (UC) is a leading form of inflammatory bowel disease that involves chronic relapsing or progressive inflammation. As a significant proportion of UC patients treated with conventional therapies do not achieve remission, there is a pressing need for the development of more effective therapies. The human gut contains a large, diverse, and dynamic population of microorganisms, collectively referred to as the enteric microbiota. There is a symbiotic relationship between the human host and the enteric microbiota, which provides nutrition, protection against pathogenic organisms, and promotes immune homeostasis. An imbalance of the normal enteric microbiota composition (termed dysbiosis) underlies the pathogenesis of UC. A reduction of enteric microbiota diversity has been observed in UC patients, mainly affecting the butyrate-producing bacteria, such as Faecalibacterium prausnitzii, which can repress pro-inflammatory cytokines. Many studies have shown that enteric microbiota plays an important role in anti-inflammatory and immunoregulatory activities, which can benefit UC patients. Therefore, manipulation of the dysbiosis is an attractive approach for UC therapy. Various therapies targeting a restoration of the enteric microbiota have shown efficacy in treating patients with active and chronic forms of UC. Such therapies include fecal microbiota transplantation, probiotics, prebiotics, antibiotics, helminth therapy, and dietary polyphenols, all of which can alter the abundance and composition of the enteric microbiota. Although there have been many large, randomized controlled clinical trials assessing these treatments, the effectiveness and safety of these bacteria-driven therapies need further evaluation. This review focuses on the important role that the enteric microbiota plays in maintaining intestinal homeostasis and discusses new therapeutic strategies targeting the enteric microbiota for UC.

Antimicrobial proteins in intestine and inflammatory bowel diseases.

Mucosal surface of the intestinal tract is continuously exposed to a large number of microorganisms. To manage the substantial microbial exposure, epithelial surfaces produce a diverse arsenal of antimicrobial proteins (AMPs) that directly kill or inhibit the growth of microorganisms. Thus, AMPs are important components of innate immunity in the gut mucosa. They are frequently expressed in response to colonic inflammation and infection. Expression of many AMPs, including human β-defensin 2-4 and cathelicidin, is induced in response to invasion of pathogens or enteric microbiota into the mucosal barrier. In contrast, some AMPs, including human α-defensin 5-6 and human β-defensin 1, are constitutively expressed without microbial contact or invasion. In addition, specific AMPs are reported to be associated with inflammatory bowel disease (IBD) due to altered expression of AMPs or development of autoantibodies against AMPs. The advanced knowledge for AMPs expression in IBD can lead to its potential use as biomarkers for disease activity. Although the administration of exogenous AMPs as therapeutic strategies against IBD is still at an early stage of development, augmented induction of endogenous AMPs may be another interesting future research direction for the protective and therapeutic purposes. This review discusses new advances in our understanding of how intestinal AMPs protect against pathogens and contribute to pathophysiology of IBD.

Autacoids in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD), including Crohn’s disease and ulcerative colitis (UC), are complex disorders characterized by chronic, local and systemic inflammation and spontaneously relapsing course. The causes of these diseases are unknown, however they display genetic and environmental components and appear to be immunologically mediated in part by enteric microbiota [1]. The immune system cells activation may lead to activation of plasma proteolytic cascades [1,2], as well as to release of inflammatory mediators in inflamed intestine. There are convincing evidences that IBD are diseases of immunological hyperresponsiveness within the mucosa. Immunological reactions may be directed against luminal bacteria and their products normally present in the intestine [2]. Both innate and adaptive immune response play a role in IBD pathogenesis and possibly in etiology. Autacoids, a local hormones e.g., histamine, serotonin, kinins, angiotensin, eicosanoids, neurotensin, nitric oxide, endothelins may be produced and act locally in IBD – inflamed intestine, and play a role inflammatory response, and progression in both Crohn’s disease and UC. A role of eicosanoids and nitric oxide in IBD was relatively well delineated. Much less attention has been paid to other autacoids, although a significance of the intestinal tissue kallikrein – kinin system in IBD has been investigated in the late 1990s – 2000s. Histamine, serotonin and kinins are vasodilator autacoids which as part of the humoral defense system participate in the inflammatory response. Enterochromaffin cellwhich are present in the mucosa of all regions of the gut except the oesophagus, contain most of the body’s serotonin (5-HT). Derived serotonin (5-HT) express toll-like receptors and thus may detect microorganisms [3,4]. Enterochromaffin cell 5-HT also appears to contribute to the initiation of intestinal inflammation, at least in the animal models. Mice that lack the 5-HT transporter (SERT; SERTKO mice), which inactivates 5-HT, are sensitive to experimentally induced colitis especially in animals with interleukin (IL)-10 deletion [5,6]. Histamine as a proinflammatory mediator is selectively located in the granules of human mast cells and basophils and released from these cells upon degranulation. It was shown that the number of mast cells and mast cells tryptase expression (a marker of mast cell degranulation are increased in colonic mucosa and submucosa in experimental and human IBD [7]. Interestingly, mast cells originated from the resected colon of active Crohn’s disease or UC released more histamine than those from normal colon after stimulation with colon-derived murine epithelial cell-associated compounds [8]. Knutson et al. found that the histamine secretion was increased in patients with Crohn’s disease compared with normal controls, and the secretion of histamine was related to disease activity, indicating strongly that degranulation of mast cells was involved in active Crohn’s disease [9]. A significance kinins in human IBD is still underestimated although in animal IBD models kinins have been documented in part to mediate intestinal and systemic inflammation. Tissue kallikrein cleaves kininogens to release kinins. The importance of intestinal tissue kallikrein (ITK) in the intestine mainly depends upon the secretion of active enzyme in the presence of kininogens, especially low molecular weight kininogen (LK), with subsequent kinins generation. It should be noted that in mild insults, kinins may play a salutary role recruiting to the extravascular milieu proteases, acute phase proteins, and neutrophils. In severe inflammation, however, kinins amplifies the inflammatory cascade, and contributes to tissue destruction. In late 1990s we have focused our attention on the ITK-kinin system in IBD. To study the localization of ITK and its naturally occurring serine protein inhibitor (SERPIN), kallistatin, in IBD we first focused in our models of rats enterocolitis induced by proteoglycan-polysaccharide (PG-APS) closely resembling Crohn’s disease [10]. We showed that the normal location of ITK was the goblet cells and that substantial amounts of ITK were present in the macrophages of the granuloma found in the submucosa, suggesting that ITK is present at the site of inflammation. In addition, ITK was found to be lower in the supernatant from in vitro cultures of inflamed intestine. This combination suggested secretion of ITK during inflammation.

Heme oxygenase-1 and carbon monoxide regulate intestinal homeostasis and mucosal immune responses to the enteric microbiota

Heme oxygenase-1 (HO-1) and its enzymatic by-product carbon monoxide (CO) have emerged as important regulators of acute and chronic inflammation. Mechanisms underlying their anti-inflammatory effects are only partially understood. In this addendum, we summarize current understanding of the role of the HO-1/CO pathway in regulation of intestinal inflammation with a focus on innate immune function. In particular, we highlight our recent findings that HO-1 and CO ameliorate intestinal inflammation through promotion of bacterial clearance. Our work and that of many others support further investigation of this global homeostatic pathway in the human inflammatory bowel diseases (IBDs).

Redox signaling regulates commensal-mediated mucosal homeostasis and restitution and requires formyl peptide receptor 1.

The mammalian gut microbiota is essential for normal intestinal development, renewal and repair. Injury to the intestinal mucosa can occur with infection, surgical trauma, and in idiopathic inflammatory bowel disease. Repair of mucosal injury, termed restitution, as well as restoration of intestinal homeostasis involves induced and coordinated proliferation and migration of intestinal epithelial cells. N-formyl peptide receptors (FPRs) are widely expressed pattern recognition receptors that can specifically bind and induce responses to host derived and bacterial peptides and small molecules. Here we report that specific members of the gut microbiota stimulate FPR1 on intestinal epithelial cells to generate reactive oxygen species via enterocyte NADPH oxidase NOX1, causing rapid phosphorylation of Focal Adhesion Kinase (FAK) and ERK MAPK. These events stimulate migration and proliferation of enterocytes adjacent to colonic wounds. Together, these findings identify a novel role of FPR1 as pattern recognition receptors for perceiving the enteric microbiota that promotes repair of mucosal wounds via generation of ROS from the enterocyte NOX1.

Prebiotic feeding elevates central brain derived neurotrophic factor, N-methyl-d-aspartate receptor subunits and d-serine

The influence of the gut microbiota on brain chemistry has been convincingly demonstrated in rodents. In the absence of gut bacteria, the central expression of brain derived neurotropic factor, (BDNF), and N-methyl-d-aspartate receptor (NMDAR) subunits are reduced, whereas, oral probiotics increase brain BDNF, and impart significant anxiolytic effects. We tested whether prebiotic compounds, which increase intrinsic enteric microbiota, also affected brain BDNF and NMDARs. In addition, we examined whether plasma from prebiotic treated rats released BDNF from human SH-SY5Y neuroblastoma cells, to provide an initial indication of mechanism of action.Rats were gavaged with fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS) or water for five weeks, prior to measurements of brain BDNF, NMDAR subunits and amino acids associated with glutamate neurotransmission (glutamate, glutamine, and serine and alanine enantiomers). Prebiotics increased hippocampal BDNF and NR1 subunit expression relative to controls. The intake of GOS also increased hippocampal NR2A subunits, and frontal cortex NR1 and d-serine. Prebiotics did not alter glutamate, glutamine, l-serine, l-alanine or d-alanine concentrations in the brain, though GOSfeeding raised plasma d-alanine. Elevated levels of plasma peptide YY (PYY) after GOS intake was observed. Plasma from GOS rats increased the release of BDNF from SH-SY5Y cells, but not in the presence of PYY antisera. The addition of synthetic PYY to SH-SY5Y cell cultures, also elevated BDNF secretion.We conclude that prebiotic-mediated proliferation of gut microbiota in rats, like probiotics, increases brain BDNF expression, possibly through the involvement of gut hormones. The effect of GOS on components of central NMDAR signalling was greater than FOS, and may reflect the proliferative potency of GOS on microbiota. Our data therefore, provide a sound basis to further investigate the utility of prebiotics in the maintenance of brain health and adjunctive treatment of neuropsychiatric disorders.

Intestinal microbiota influence the early postnatal development of the enteric nervous system

Normal gastrointestinal function depends on an intact and coordinated enteric nervous system (ENS). While the ENS is formed during fetal life, plasticity persists in the postnatal period during which the gastrointestinal tract is colonized by bacteria. We tested the hypothesis that colonization of the bowel by intestinal microbiota influences the postnatal development of the ENS. The development of the ENS was studied in whole mount preparations of duodenum, jejunum, and ileum of specific pathogen-free (SPF), germ-free (GF), and altered Schaedler flora (ASF) NIH Swiss mice at postnatal day 3 (P3). The frequency and amplitude of circular muscle contractions were measured in intestinal segments using spatiotemporal mapping of video recorded spontaneous contractile activity with and without exposure to lidocaine and N-nitro-L-arginine (NOLA). Immunolabeling with antibodies to PGP9.5 revealed significant abnormalities in the myenteric plexi of GF jejunum and ileum, but not duodenum, characterized by a decrease in nerve density, a decrease in the number of neurons per ganglion, and an increase in the proportion of myenteric nitrergic neurons. Frequency of amplitude of muscle contractions were significantly decreased in the jejunum and ileum of GF mice and were unaffected by exposure to lidocaine, while NOLA enhanced contractile frequency in the GF jejunum and ileum. These findings suggest that early exposure to intestinal bacteria is essential for the postnatal development of the ENS in the mid to distal small intestine. Future studies are needed to investigate the mechanisms by which enteric microbiota interact with the developing ENS.

Digestion of epithelial tight junction proteins by the commensalClostridium perfringens

The enteric microbiota contributes to the pathogenesis of inflammatory bowel disease, but the pathways involved and bacterial participants may vary in different hosts. We previously reported that some components of the human commensal microbiota, particularly Clostridium perfringens (C. perfringens), have the proteolytic capacity for host matrix degradation and reduce transepithelial resistance. Here, we examined the C. perfringens-derived proteolytic activity against epithelial tight junction proteins using human intestinal epithelial cell lines. We showed that the protein levels of E-cadherin, occludin, and junctional adhesion molecule 1 decrease in colonic cells treated with C. perfringens culture supernatant. E-cadherin ectodomain shedding in C. perfringens-stimulated intestinal epithelial cells was detected with antibodies against the extracellular domain of E-cadherin, and we demonstrate that this process occurs in a time- and dose-dependent manner. In addition, we showed that the filtered sterile culture supernatant of C. perfringens has no cytotoxic activity on the human intestinal cells at the concentrations used in this study. The direct cleavage of E-cadherin by the proteases from the C. perfringens culture supernatant was confirmed by C. perfringens supernatant-induced in vitro degradation of the human recombinant E-cadherin. We conclude that C. perfringens culture supernatant mediates digestion of epithelial cell junctional proteins, which is likely to enable access to the extracellular matrix components by the paracellular pathway.

A monoclonal antibody-based sandwich enzyme-linked immunosorbent assay for detection of secreted α-defensin

Paneth cells at the base of small intestinal crypts secrete α-defensins, which contribute to innate immunity and shape composition of enteric microbiota. Efforts to establish a relationship between secreted α-defensins and disease have been hampered by a lack of sensitive assays to quantify luminal α-defensins. Here we report on a highly sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for the mouse Paneth cell α-defensin cryptdin-4 (Crp4) in varied sources, including luminal contents rinsed from stomach to distal colon and fecal pellets. One pair of monoclonal antibodies (mAbs), selected from 10 rat hybridomas secreting Crp4-specific mAbs, was optimized for Crp4 detection and specificity in the sandwich ELISA. In CD1 mice, luminal Crp4 levels increased gradually from 6.8±5.2ng/ml in proximal small intestine to 54.3±10.3ng/ml in distal small intestine, and the peptide was detected in colonic lumen and feces. Secreted Crp4 was reduced significantly in feces of IL10 null mice, a model of inflammatory bowel disease (IBD) when compared with wild-type controls. This Crp4 sandwich ELISA enables accurate determinations of luminal α-defensins as biomarkers of Paneth cell function and enteric integrity in diverse disease states such as IBD, infectious disease, graft versus host disease, and obesity in association with dysbiosis of the intestinal microbiota.

Dietary Manipulation of the Enteric Microbiota to Treat Irritable Bowel Syndrome

Dietary Manipulation of the Enteric Microbiota to Treat Irritable Bowel Syndrome

Exploring the immunomodulatory potential of microbial-associated molecular patterns derived from the enteric bacterial microbiota

The human intestinal lumen represents one of the most densely populated microbial niches in the biological world and, as a result, the intestinal innate immune system exists in a constant state of stimulation. A key component in the innate defence system is the intestinal epithelial layer, which acts not only as a physical barrier, but also as an immune sensor. The expression of pattern recognition receptors, such as Toll-like receptors, in epithelial cells allows innate recognition of a wide range of highly conserved bacterial moieties, termed microbial-associated molecular patterns (MAMPs), from both pathogenic and non-pathogenic bacteria. To date, studies of epithelial immunity have largely concentrated on inflammatory pathogenic antigens; however, this review discusses the major types of MAMPs likely to be produced by the enteric bacterial microbiota and, using data from in vitro studies, animal model systems and clinical observations, speculates on their immunomodulatory potential.

Altered enteric microbiota ecology in interleukin 10-deficient mice during development and progression of intestinal inflammation

Inflammatory bowel diseases (IBD) result from dysregulated immune responses toward microbial and perhaps other luminal antigens in a genetically susceptible host, and are associated with altered composition and diversity of the intestinal microbiota. The interleukin 10-deficient (IL-10−/−) mouse has been widely used to model human IBD; however the specific alterations that occur in the intestinal microbiota of this mouse model during the onset of colonic inflammation have not yet been defined. The aim of our study was to define the changes in diversity and composition that occur in the intestinal microbiota of IL-10−/− mice during the onset and progression of colonic inflammation. We used high throughput sequencing of the 16S rRNA gene to characterize the diversity and composition of formerly germ-free, wild-type and IL-10−/− mice associated with the same intestinal microbiota over time. Following two weeks of colonization with a specific pathogen-free (SPF) microbiota we observed a significant increase in the diversity and richness of the intestinal microbiota of wild-type mice. In contrast, a progressive decrease in diversity and richness was observed at three and four weeks in IL-10−/− mice. This decrease in diversity and richness was mirrored by an increase in Proteobacteria and Escherichia coli in IL-10−/− mice. An increase in E. coli was also observed in conventionally raised IL-10−/− mice at the point of colonic inflammation. Our data reports the sequential changes in diversity and composition of the intestinal microbiota in an immune-mediated mouse model that may help provide insights into the primary vs. secondary role of dysbiosis in human IBD patients.

Sa1960 Risk of Upper Gastrointestinal Complications and the Use of Individual NSAIDs: A Nested Case-Control Study From the Sos Project

Background . Proton pump inhibitors (PPIs) are commonly coprescribed to reduce gastroduodenal injury caused by Non Steroidal Anti-Inflammatory Drugs (NSAIDs). However, while suppression of gastric acid secretion by PPIs is highly effective in reducing gastric injury, PPIs might worsen intestinal injury caused by non selective COX inhibitors. This so-called NSAIDs-PPIs enteropathy has been linked to development of an altered microbiota. Aims. To investigate whether probiotics prevent development of intestinal injury in a model of NSAIDs-PPIs enteropathy.Methods. Mice administered with omeprazole 10 mg/kg (ip twice daily) for 9 days, treated with naproxen (50 mg/kg per os) on the final 4 days. The probiotic VSL#3 at the dose of 18 x109 UCF daily (per os) was administered for 9 days. Small intestinal damage was scored, changes in hematocrit, gastric pH, intestinal expression of IL-1 β, and TNFαmRNA were measured. Change in small intestinal microbiota was assessed by terminal restriction fragment lenght polymorphisms (T-RFLP). To produce terminal restriction fragments the 16S rRNA was amplified and digested with HaeIII. Results. Treating mice with omeprazole increased significantly gastric pH from 2,43±0,29 to 3,66±0,2 (naproxen +omeprazole group) and 3,9 ±0,18 (naproxen + omeprazole +VSL#3 group) and reduced significantly the severity of gastric injury score (mm of lesion) from 20,17±4,8 (naproxen group) to 6±1,15 (naproxen+ omeprazole group) and 7±2,4 (naproxen+ omeprazole+VSL#3 group). In contrast, intestinal injury (mm of lesion) caused by naproxen was exacerbated by omeprazole administration from 37,5±12,12 (naproxen group) to 84,17±11,56 (naproxen + omeprazole group; P,0.05). This effect was reversed by VSL#3. Naproxen alone and naproxen + omeprazole increased the ileal expression of IL-1 β and TNF α, two markers of mucosal inflammation. This effect was reversed by VSL#3. Finally, VSL#3 administration resulted in a robust colonization of small intestine as assessed by T-RFLP. Conclusions. Omeprazole exacerbates naproxen -induced intestinal damage at least in part because of significant shifts in enteric microbiota. VSL#3 has been shown effective in reducing intestinal injury caused by indomethacin in human (APT32:209) and might hold utility in the prevention of NSAIDs-PPIs enteropathy.

Similaridade genética entre APEC e cepas de Escherichia coli isoladas de Guaruba guarouba em um estudo com psitacídeos hígidos de cativeiro

The role of psittacine birds as a reservoir of avian pathogenic Escherichia coli (APEC) is not known but would be helpful in understanding the human – animal interface, since the enteric microbiota of these birds consists of Gram positive bacteria. The aim of this study was to identify the presence of APEC in feces of clinically healthy Guaruba guarouba. To do this, we isolated and analyzed E. coli from cloacal fecal samples taken from 87 psittacine birds from six zoologic parks, three commercial breeders and one conservation breeder. Of the 87 birds examined, 46 (52.87%) presented E. coli in feces. The presence of the following eight virulence genes was determined by the polymerase chain reaction (PCR): irp2, iucD, iss, vat, cvi/cva, tsh, astA, and papC, and 29 (63.04%) of 46 E. coli isolates tested were positive at least one of the eight genes studied. The frequency of virulence genes observed in isolates of E. coli were 32.6% (15/46) irp2, 26% (12/46) iucD, 19.5% iss (9/46), 17.4% vat (8/46), 17.4% cvi/cva (8/46), 8.7% tsh (4/46), 4.4% astA (2/46) and 0% papC (0/46). The isolates were grouped in 13 genotypic profiles according to virulence gene combinations, but only 2 isolates were classified as APEC, with the pattern iuc, iss, cvi/cva, irp + and iuc, iss, cvi/cva, irp, tsh, vat +. This study reveals the presence of APEC in clinically healthy captive G. guarouba, suggesting that these psittacine birds may act as reservoir for pathogenic microorganisms. Epidemiological studies are needed to determine the relevance of this species as a reservoir and the implications for conservation of endangered species G. guarouba.

Ileal flows and apparent ileal digestibility of fatty acids in growing gilts fed flaxseed containing diets1

An experiment was conducted to quantify the ileal flow and apparent ileal digestibility (AID) of fatty acids (FA) in growing gilts fed corn, wheat, and soybean meal based diets without (CON) or with ground flaxseed (FS). A total of 20 healthy purebred Yorkshire female pigs, weighing approximately 25 kg BW, were allotted to 1 of 3 feeding regimens: R1 (n = 5 pigs), feeding a diet containing 10% FS between 25 and 50 kg BW and CON diet thereafter, R2 (n = 10 pigs), feeding CON diet between 25 and 85 kg BW and a diet containing 6% FS thereafter, and R3 (n = 5 pigs), feeding CON diet between 25 and 110 kg BW. Titanium dioxide was used as an indigestible marker to assess AID and ileal flows of crude fat and FA. At 110 kg BW, pigs were slaughtered and representative digesta samples were obtained from the distal ileum. Ileal flows and AID of crude fat and individual FA did not differ (P > 0.10) between R1 and R3, and therefore, results from these 2 feeding regimens were combined to give 2 dietary treatments (CON and FS). There were no treatment effects on AID of crude fat and the sum of all FA, SFA, or MUFA. However, the AID of individual SFA decreased with chain length (linear; P < 0.05) for both FS and CON. The AID of myristic acid (14:0), individual trans-18:1 FA (6t-8t-18:1 to 12t-18:1), myristoleic acid (9c-14:1), and palmitoleic acid (9c-16:1) were greater for CON than FS (P < 0.05) whereas no diet effect was observed for the AID of linoleic acid (18:2n-6; 80.2 and 86.1% for FS and CON, respectively) and α-linolenic acid (18:3n-3; 86.7 and 89.8% for FS and CON, respectively). Ileal flows of rumenic acid (9c11t-CLA), n-3 PUFA, and highly unsaturated FA (HUFA; arachidonic, eicosatrienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) exceeded their intakes, indicating net appearance of these FA in the upper gut of the pig. It remains to be determined whether enteric microbiota can elongate and desaturate 18:2n-6 and 18:3n-3 and isomerize 18:2n-6. The contribution of endogenous FA losses from the host to the ileal flow of these FA should also be considered. Further studies are needed to quantify production of CLA isomers and PUFA in the small intestine of pigs, specifically the n-3 HUFA, and to assess their contribution to the FA supply of the host.

Linking the gut microbiota to human health

The human gut is the natural environment for a diverse and dynamic microbial ecosystem, whose structure and functions are presently a major target of research in biomedicine. Experimental studies in germ-free animals performed some decades ago revealed the importance of these microbial communities for normal growth and development and for the maintenance of health in adult life. The host provides habitat and nutrition to the microbial communities and derives many benefits from its symbionts that contribute to metabolic, defensive and trophic functions. Development of novel gene sequencing technologies as well as availability of powerful bioinformatic analysis tools provide new insights into the composition and structure of the human gut microbiota. There is no clear definition of the characteristics of a normal 'healthy' gut microbiota in human subjects, but several disease states have been associated with changes in the composition of faecal and intestinal mucosal communities, including inflammatory bowel diseases, obesity and the metabolic syndrome. Probiotics and prebiotics are used to improve symbiosis between enteric microbiota and the host or restore states of dysbiosis.