Intestinal Tract (intestinal + tract)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Intestinal Tract

  • human intestinal tract

  • Selected Abstracts

    Probiotic and Prebiotic Influence Beyond the Intestinal Tract

    NUTRITION REVIEWS, Issue 11 2007
    Irene Lenoir-Wijnkoop
    Probiotics and prebiotics have long been appreciated for their positive influences on gut health. Research on the mechanisms and effects of these agents shows that their impact reaches beyond the intestine. Effects on the microecology and pathology of the oral cavity, stomach, and vaginal tract have been observed. Likely mediated through immune influences, systemic effects such as reduced severity of colds or other respiratory conditions, impact on allergy incidence and symptoms, and reduced absences from work or daycare have also been noted. These observations, among others, suggest a broader spectrum of influence than commonly considered for these unique substances. [source]

    Observations on the Macroscopic Anatomy of the Intestinal Tract and its Mesenteric Folds in the Pampas Deer (Ozotoceros bezoarticus, Linnaeus 1758)

    W. Pérez
    Summary We described the macroscopic anatomy of the intestines and their peritoneal folds of five adult pampas deer (Ozotoceros bezoarticus), a cervid species considered to ingest a high proportion of grass in its natural diet. The mean (±SD) body weight was 17 (±2) kg. The small intestine and the caecocolon measured 495 (±37) cm and 237 (±24) cm in length, respectively, with an average ratio (small intestine:caecocolon) of 1.9 (±0.1). The ascending colon had two and a half centripetal gyri, a central flexure and two centrifugal gyri. The spiral ansa, which was similar to an ellipse, was fixed to the whole left face of the mesenterium. Apart from the peritoneal folds described in the Nomina Anatomica Veterinaria, three additional, hitherto not described folds were found: a fold that fixed the caecum to the proximal ansa of the ascending colon, one that joined the terminal part of the proximal ansa to the last centrifugal gyrus of the spiral ansa of the ascending colon, and one that linked the ascending duodenum to the proximal ansa of the ascending colon. When compared with published data from other cervids of different feeding niches, it appears that, among cervids, the ratio of small intestine to the caecocolon length does not reflect the natural diet. [source]

    Niche heterogeneity determines bacterial community structure in the termite gut (Reticulitermes santonensis)

    Hong Yang
    Summary Differences in microenvironment and interactions of microorganisms within and across habitat boundaries should influence structure and diversity of the microbial communities within an ecosystem. We tested this hypothesis using the well characterized gut tract of the European subterranean termite Reticulitermes santonensis as a model. By cloning and sequencing analysis and molecular fingerprinting (terminal restriction fragment length polymorphism), we characterized the bacterial microbiota in the major intestinal habitats , the midgut, the wall of the hindgut paunch, the hindgut fluid and the intestinal protozoa. The bacterial community was very diverse (> 200 ribotypes) and comprised representatives of several phyla, including Firmicutes (mainly clostridia, streptococci and Mycoplasmatales -related clones), Bacteroidetes, Spirochaetes and a number of Proteobacteria, all of which were unevenly distributed among the four habitats. The largest group of clones fell into the so-called Termite group 1 (TG-1) phylum, which has no cultivated representatives. The majority of the TG-1 clones were associated with the protozoa and formed two phylogenetically distinct clusters, which consisted exclusively of clones previously retrieved from the gut of this and other Reticulitermes species. Also the other clones represented lineages of microorganisms that were exclusively recovered from the intestinal tract of termites. The termite specificity of these lineages was underscored by the finding that the closest relatives of the bacterial clones obtained from R. santonensis were usually derived also from the most closely related termites. Overall, differences in diversity between the different gut habitats and the uneven distribution of individual phylotypes support conclusively that niche heterogeneity is a strong determinant of the structure and spatial organization of the microbial community in the termite gut. [source]

    Population genetics of Escherichia coli in a natural population of native Australian rats

    Gulietta M. Pupo
    Escherichia coli, a normal inhabitant of the intestinal tract of mammals and birds, is a diverse species. Most studies on E. coli populations involve organisms from humans or human-associated animals. In this study, we undertook a survey of E. coli from native Australian mammals, predominantly Rattus tunneyi, living in a relatively pristine environment in the Bundjalung National Park. The genetic diversity was assessed and compared by multilocus enzyme electrophoresis (MLEE), sequence analysis of the mdh (malate dehydrogenase) gene and biotyping using seven sugars. Ninety-nine electrophoretic types were identified from the 242 isolates analysed by MLEE and 15 sequences from the mdh genes sequenced from 21 representative strains. The Bundjalung isolates extend the diversity represented by the E. coli reference (ECOR) set, with new MLEE alleles found in six out of 10 loci. Many of the Bundjalung isolates fell into a discrete group in MLEE. Other Bundjalung strains fell into the recognized E. coli ECOR set groups, but tended to be at the base of both the MLEE and mdh gene trees, implying that these strains are derived independently from ancestral forms of the ECOR groups and that ECOR strains represent only a subset of E. coli adapted to humans and human-associated animals. Linkage disequilibrium analysis showed that the Bundjalung population has an ,epidemic' population structure. The Bundjalung isolates were able to utilize more sugars than the ECOR strains, suggesting that diet plays a prominent role in adaptation of E. coli. [source]

    End-to-end jejuno-ileal anastomosis following resection of strangulated small intestine in horses: a comparative study

    D. I. RENDLE
    Summary Reasons for performing study: Small intestinal resection and anastomosis is a relatively common procedure in equine surgical practice. This study was designed to test objectively the subjective opinions of surgeons at the Liphook Equine Hospital that an end-to-end jejuno-ileal anastomosis (JIA) is an effective and clinically justifiable procedure, contrary to conventional recommendations. Hypothesis: An end-to-end JIA carries no greater risk of morbidity and mortality than an end-to-end jejunojejunal anastomosis (JJA). Methods: A retrospective observational study was performed on a population of 100 horses that had undergone small intestinal resection and end-to-end anastomosis. Two groups were identified; Group 1 (n = 30) had undergone an end-to-end JIA and Group 2 (n = 70) an end-to-end JJA. The 2 populations were tested for pre- and intraoperative comparability and for their equivalence of outcomes. Results: The 2 populations were comparable in terms of their distributions of preoperative parameters and type of lesion present. The observations used as outcome parameters (incidence risk of post operative colic, incidence risk of post operative ileus, duration of post operative ileus, rates of functioning original anastomoses at the time of discharge and at 12 months, survival rates at 6 months and 12 months) were equivalent between the 2 groups. Conclusion: End-to-end JIA carries no greater risk of morbidity and mortality than an end-to-end JJA. Potential relevance: Surgeons faced with strangulating obstructions involving the jejuno-ileal junction in which there remains an accessible length of viable terminal ileum may reasonably perform an end-to-end JIA. This has the potentially significant advantage over a jejunocaecal anastomosis of preserving more anatomical and physiological normality to the intestinal tract. The study was, however, relatively small for an equivalence study and greater confidence would be gained with higher numbers. [source]

    A randomized controlled trial of transcatheter arterial chemoembolization with lipiodol, doxorubicin and cisplatin versus intravenous doxorubicin for patients with unresectable hepatocellular carcinoma

    M. MABED md, professor
    Hepatocellular carcinoma (HCC) is a major and often therapeutically frustrating oncological problem. A total of 100 patients with unresectable HCC were recruited and randomized to be treated with either transcatheter arterial chemoembolization (TACE) or systemic chemotherapy. Fifty patients were treated with TACE using lipiodol, doxorubicin and cisplatin, while 50 patients were treated with systemic doxorubicin alone. Patients treated with TACE achieved a significantly higher response rate, with partial response achieved in 16 patients (32%) versus five patients (10%) in the chemotherapy arm (P = 0.007). A significantly more favourable tumour response to chemoembolization was found in patients with single lesions (P = 0.02), Child class A (P = 0.007), Okuda stage 1 (P = 0.005) and ,-feto protein less than 400 ng/mL (P < 0.001). The probability of tumour progression was significantly lower in cases treated with TACE where the median progression free survival was 32 weeks (range, 16,70 weeks) versus 26 weeks (range, 14,54 weeks) for patients treated with systemic chemotherapy (P = 0.03). However, the median overall survival did not differ significantly in cases treated with TACE (38 weeks) compared with those treated with chemotherapy (32 weeks) (P = 0.08), except for patients with serum albumin >3.3 g/dL (60 vs. 36 weeks; P = 0.003). Multivariate Cox regression analysis showed that a rise of serum albumin by 1 g/dL is associated with a decrease in the risk of death by 33% (95% confidence interval: 0.12,0.94, P = 0.038). Mortality in the chemoembolization arm was due to tumour progression in 18 patients (53%), liver failure in 11 patients (32%) and gastro intestinal tract (GIT) bleeding in 5 patients (15%). Mortality in the chemotherapy arm was due to tumour progression in 23 patients (64%), liver failure in 9 patients (25%) and GIT bleeding in 4 patients (11%). Treatment-related mortality was 4% in the TACE arm versus 0% in the chemotherapy arm. In conclusion, the overall survival benefits of TACE and systemic doxorubicin are similar for patients with unresectable HCC amenable to either treatment. It is crucial to optimize the benefit,risk ratio of TACE. In this setting, serum albumin level is a candidate marker for selection of cases who may benefit from this procedure. [source]

    Site-specific expression of CD11b and SIRP, (CD172a) on dendritic cells: implications for their migration patterns in the gut immune system

    Diane Bimczok
    Abstract Dendritic cells (DC) in the intestinal tract play a major role in directing the mucosal immune system towards tolerance or immunity. We analyzed whether different mucosal DC subsets in pigs have specific functions, localizations, or migration patterns in vivo. Therefore, we collected physiologically migrating DC by pseudo-afferent cannulation of the intestinal duct in eight Göttingen minipigs. Lymph DC were phenotypically and functionally characterized and compared to DC found on histological sections of porcine small intestine and mesenteric lymph nodes (MLN). Four different DC subpopulations were detected. Lamina propria (LP) DC were mainly CD11b+ signal regulatory protein,, (SIRP,)+, DC in Peyer's patches were mainly CD11b,/SIRP,+ in subepithelial domes and CD11b,/SIRP,, in interfollicular regions, whereas MLN DC were largely CD11b+/SIRP,,. Of these four subsets, only the CD11b+/SIRP,+ DC and the CD11b+/SIRP,, DC were present in lymph. This suggests that DC migration to MLN largely originates from the LP. Lymph DC expressed high levels of MHC class,II and costimulatory molecules and had a low capacity for FITC-dextran uptake, indicating a mature phenotype. However, lymph DC did not induce PBMC proliferation in MLR, and migration was not significantly influenced by mucosal antigen application. [source]

    Cloning, chromosomal localization and characterization of the murine mucin gene orthologous to human MUC4

    FEBS JOURNAL, Issue 13 2002
    Jean-Luc Desseyn
    We report here the full coding sequence of a novel mouse putative membrane-associated mucin containing three extracellular EGF-like motifs and a mucin-like domain consisting of at least 20 tandem repeats of 124,126 amino acids. Screening a cosmid and a BAC libraries allowed to isolate several genomic clones. Genomic and cDNA sequence comparisons showed that the gene consists of 25 exons and 24 introns covering a genomic region of ,,52 kb. The first intron is ,,16 kb in length and is followed by an unusually large exon (, 9.5 kb) encoding Ser/Thr-rich tandemly repeated sequences. Radiation hybrid mapping localized this new gene to a mouse region of chromosome 16, which is the orthologous region of human chromosome 3q29 encompassing the large membrane-anchored mucin MUC4. Contigs analysis of the Human Genome Project did not reveal any other mucin on chromosome 3q29 and, interestingly, our analysis allowed the determination of the genomic organization of the human MUC4 and showed that its exon/intron structure is identical to that of the mouse gene we cloned. Furthermore, the human MUC4 shares considerable homologies with the mouse gene. Based on these data, we concluded that we isolated the mouse ortholog of MUC4 we propose as Muc4. Expression studies showed that Muc4 is ubiquitous like SMC and MUC4, with highest levels of expression in trachea and intestinal tract. [source]

    From soil to gut: Bacillus cereus and its food poisoning toxins

    Lotte P. Stenfors Arnesen
    Abstract Bacillus cereus is widespread in nature and frequently isolated from soil and growing plants, but it is also well adapted for growth in the intestinal tract of insects and mammals. From these habitats it is easily spread to foods, where it may cause an emetic or a diarrhoeal type of food-associated illness that is becoming increasingly important in the industrialized world. The emetic disease is a food intoxication caused by cereulide, a small ring-formed dodecadepsipeptide. Similar to the virulence determinants that distinguish Bacillus thuringiensis and Bacillus anthracis from B. cereus, the genetic determinants of cereulide are plasmid-borne. The diarrhoeal syndrome of B. cereus is an infection caused by vegetative cells, ingested as viable cells or spores, thought to produce protein enterotoxins in the small intestine. Three pore-forming cytotoxins have been associated with diarrhoeal disease: haemolysin BL (Hbl), nonhaemolytic enterotoxin (Nhe) and cytotoxin K. Hbl and Nhe are homologous three-component toxins, which appear to be related to the monooligomeric toxin cytolysin A found in Escherichia coli. This review will focus on the toxins associated with foodborne diseases frequently caused by B. cereus. The disease characteristics are described, and recent findings regarding the associated toxins are discussed, as well as the present knowledge on virulence regulation. [source]

    Visualization of Helicobacter Species Within the Murine Cecal Mucosa Using Specific Fluorescence In Situ Hybridization

    HELICOBACTER, Issue 2 2005
    Vivian Chan
    ABSTRACT Background., Members of the genus Helicobacter have been associated with colitis development in a number of immunodeficient animal models. While it is known that these organisms can initiate colitis development, the location and spatial distribution of these bacteria within the intestinal tract is currently unknown. In this study, we developed and optimized fluorescence in situ hybridization (FISH) probes specifically for Helicobacter species. Materials and Methods., Based on 16S-RNA gene alignments, two probes specific for the entire family Helicobacteraceae and two probes specific for Helicobacter ganmani and Helicobacter hepaticus were designed. Evaluation of these probes was determined using ATCC reference strains and cecum samples from ten IL-10 knockout mice. The presence of Helicobacter species was determined using FISH and verified using PCR-DGGE and microscopic examination of silver stained sections. Results., Analysis of the ATCC reference strains revealed that the probes HEL274/HEL717 were specific for the family Helicobacteraceae, while HEP642 was specific for H. hepaticus and GAN1237 for H. ganmani. Using these probes, a pattern of spatial localization of the two different Helicobacter species was observed in the cecum tissues of IL-10 knockout mice. This consistently showed that H. ganmani was localized to the lower regions and H. hepaticus to the mid-upper regions of the crypts. Conclusion., We have developed FISH probes specific for the family Helicobacteraceae as well as two individual Helicobacter species. This study will allow the future use of the FISH to better understand host-pathogen interactions in vitro. [source]

    Cytokine-mediated control of lipopolysaccharide-induced activation of small intestinal epithelial cells

    IMMUNOLOGY, Issue 3 2007
    Michael Lotz
    Summary Cytokines with anti-inflammatory properties have been implicated in the prevention of inappropriate immune activation by commensal bacteria in the intestinal tract. Here, we analysed receptor expression, cellular signalling, and the inhibitory activity of interleukin (IL)-4, -10, -11, and -13 as well as of transforming growth factor-, on lipopolysaccharide-mediated small intestinal epithelial cell activation. Only IL-4 and IL-13 had a significant inhibitory effect on chemokine secretion and nitric oxide (NO) production in differentiated and polarized cells. Reverse transcription,polymerase chain reaction of primary intestinal epithelial cells obtained by laser-microdissection confirmed expression of the type II IL-4 receptor consisting of the IL-4 receptor , and the IL-13 receptor ,1. Also, IL-4 or IL-13 led to rapid signal transducer and activator of transcription 6 phosphorylation, diminished inducible NO synthase expression, and enhanced the antagonistic arginase 1 activity. In conclusion, cytokines such as IL-4 and IL-13 affect intestinal epithelial cells and exhibit a modulating activity on Toll-like receptor-4-mediated epithelial cell activation. [source]

    Mechanisms and modulation of intestinal epithelial repair

    Dr. Axel U. Dignass
    Abstract The mucosal epithelium of the alimentary tract represents a crucial barrier to a broad spectrum of noxious and immunogenic substances within the intestinal lumen. An impairment of the integrity of the mucosal epithelial barrier is observed in the course of various intestinal disorders including inflammatory bowel diseases (IBD), celiac disease, intestinal infections, and various other diseases. Furthermore, even under physiologic conditions temporary damage of the epithelial surface mucosa may be caused by proteases, residential flora, dietary compounds, or other factors. Generally, the integrity of the intestinal mucosal surface barrier is rapidly reestablished even after extensive destruction because of an enormous regenerative capability of the mucosal surface epithelium. Rapid resealing of the surface epithelium is accomplished by epithelial cell migration, also termed epithelial restitution, epithelial cell proliferation, and differentiation. Healing of the intestinal surface epithelium is regulated by a complex network of highly divergent factors, among them a broad spectrum of structurally distinct regulatory peptides that have been identified within the mucosa of the intestinal tract. These regulatory peptides, conventionally designated as growth factors and cytokines, play an essential role in regulating differential epithelial cell functions to preserve normal homeostasis and integrity of the intestinal mucosa. In addition, a number of other peptide molecules such as extracellular matrix factors and blood clotting factors, and also nonpeptide molecules including phospholipids, short-chain fatty acids, adenine nucleotides, trace elements, and pharmacological agents, have been demonstrated to modulate intestinal epithelial repair mechanisms. Some of these molecules may be released by platelets, adjacent stromal cells, inflammatory cells, or injured epithelial and nonepithelial cells and may play an important role in the modulation of intestinal injury. Repeated damage and injury of the intestinal surface are key features of various intestinal disorders including IBD and require constant repair of the epithelium. Enhancement of intestinal repair mechanisms by regulatory peptides or other modulatory factors may provide future approaches for the treatment of diseases that are characterized by injuries of the epithelial surface. [source]

    In vitro bioaccessibility of iron and zinc in fortified fruit beverages

    Antonio Cilla
    Summary Iron and zinc bioaccessibility was estimated in the in vitro gastrointestinal digests of six different fortified fruit beverages (Fb) containing iron and/or zinc and/or skimmed milk (M). Solubility values can be used to establish trends in relative bioavailability of iron and zinc, as the first stage towards mineral bioavailability comprises solubility in the intestinal tract. FbFe, FbFeM and FbFeZnM samples showed iron bioaccessibility above 88%, differing (P < 0.05) from those of FbFeZn (53%). In turn, FbZn, FbFeZn and FbZnM samples presented higher zinc bioaccessibility (above 68%), differing (P < 0.05) from those of FbFeZnM (48%). The presence of milk-derived caseinophosphopeptides (CPPs) formed during gastrointestinal digestion in dairy samples does not increase iron or zinc bioaccessibility in FbFeM or FbZnM vs. FbFe or FbZn, but it is hypothesised that the negative interacting effect of zinc upon iron bioaccessibility when co-supplemented in these fruit beverages is overcome in the presence of CPPs, which favour iron solubility more than in the case of zinc. [source]

    The effect of Pediococcus acidilactici on the gut microbiota and immune status of on-growing red tilapia (Oreochromis niloticus)

    R.M.W. Ferguson
    Abstract Aim:, To assess Pediococcus acidilactici as a dietary supplement for on-growing red tilapia (Oreochromis niloticus). Methods and Results:, Tilapia were fed either a control diet or control diet supplemented with Ped. acidilactici at 107 CFU g,1 for 32 days. Ped. acidilactici colonized the intestinal tract and significantly affected the intestinal microbial communities. PCR-DGGE revealed direct antagonism of gastric Ped. acidilactici with an endogenous uncultured bacterium during a period of reverting to nonsupplemented feeding. Light microscopy revealed that gut integrity and leucocyte levels were unaffected by Ped. acidilactici; however, blood leucocyte levels and serum lysozyme activity were elevated after 14-days' feeding. No significant improvements in growth performance were observed at the end of the trial (day 32), but survival was significantly higher in the probiotic group. Conclusions:, The study demonstrates that oral supplementation of Ped. acidilactici modulates intestinal bacterial communities in on-growing red tilapia and also stimulates some aspects of the nonspecific immune response. Significance and Impact of the study:, To our knowledge this is the first study assessing the effects of probiotics on the gut microbiota of tilapia using culture-independent methods. Such methods are crucial to understand the mechanisms which underpin and mediate host benefits. [source]

    OmpA is an adhesion factor of Aeromonas veronii, an optimistic pathogen that habituates in carp intestinal tract

    A. Namba
    Abstract Aims:, In the present study, we focused on one of the Aeromonas veronii isolates that exhibited marked adhesion onto carp intestine and studied its membrane-associated proteins for their possible involvement in mucosal adhesion. Methods and Results:, We isolated a strain of Aer. veronii (CWP11) that exhibited a high degree of temperature-dependent adhesion activity onto carp intestinal tract and studied its adhesion factor. A proteomic analysis of the membrane-associated fraction showed the presence of multiple proteins that were specifically expressed in CWP11 cells cultured at 25°C. Of these, a 30 kDa protein was identified to be OmpA by a mass fingerprint analysis. Cloning and nucleotide sequencing of the ompA region of CWP11 revealed the presence of two tandem ompA homologues (ompAI - ompAII). Escherichia coli that expressed either OmpAI or OmpAII exhibited marked adhesion onto carp intestinal surface. Disruption of ompAI by a homologous recombination technique resulted in marked reduction of the adhesion activity in CWP11. Conclusion:, The OmpA homologue plays an important role in the adhesion of the Aer. veronii strain onto the surface of intestinal tract. Significance and Impact of the Study:, We successfully identified an OmpA homologue to be an adhesion factor of Aer. veronii, an optimistic pathogen that habituates in carp intestinal tract. [source]

    Antimicrobial activity of essential oils and structurally related synthetic food additives towards selected pathogenic and beneficial gut bacteria

    W. Si
    Abstract Aims:, To assess the potential of essential oils and structurally related synthetic food additives in reducing bacterial pathogens in swine intestinal tract. Methods and Results:, The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Among 66 essential oils/compounds that exhibited ,80% inhibition towards Salmonellatyphimurium DT104 and Escherichia coli O157:H7, nine were further studied. Most of the oils/compounds demonstrated high efficacy against S. typhimurium DT104, E. coli O157:H7, and E. coli with K88 pili with little inhibition towards lactobacilli and bifidobacteria. They were also tolerant to the low pH. When mixed with pig cecal digesta, these oils/compounds retained their efficacy against E. coli O157:H7. In addition, they significantly inhibited E. coli and coliform bacteria in the digesta, but had little effect on the total number of lactobacilli and anaerobic bacteria. Conclusions:, Some essential oils/compounds demonstrated good potential, including efficacy, tolerance to low pH, and selectivity towards bacterial pathogens, in reducing human and animal bacterial pathogens in swine intestinal tract. Significance and Impact of the Study:, This study has identified candidates of essential oils/compounds for in vivo studies to develop antibiotic substitutes for the reduction of human and animal bacterial pathogens in swine intestinal tract. [source]

    Benzoic acid-degrading bacteria from the intestinal tract of Macrotermes michaelseni Sjöstedt

    David Kamanda Ngugi
    Abstract The intestinal tracts of termites host a wide variety of microbial symbionts, which have been implicated in degradative processes. In this study, a fungus-cultivating termite, Macrotermes michaelseni was found to harbor 2.2 × 106 bacterial cells per ml of gut homogenates capable of degrading benzoic acid. Two benzoic acid degrading bacteria were isolated from the highest dilution of gut homogenates in oxic media with benzoic acid as the sole carbon source. Isolate CBC was related to Stenotrophomonas maltophila LMG 958T, Xanthomonas campestris DSM 3586T and Stenotrophomonas acidaminophila DSM 13117T with a sequence similarity of 98.3%, 94.7% and 94.2%, respectively. Isolate CBW was related to Enterobacter aerogenes JCM 1235T and Raoultella ornithinolytica ATCC 31898T with sequence similarity of 98.4% and 97.8%, respectively. In addition to growing on benzoic acid (up to 9 mM) aerobically, isolate CBW also degraded benzoic acid under anoxic conditions with nitrate as electron acceptor. Isolate CBC did not degrade bezoic acid with nitrate but could degraded resorcinol under oxic conditions. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Isolation and identification of mixed linked , -glucan degrading bacteria in the intestine of broiler chickens and partial characterization of respective 1,3-1,4- , -glucanase activities

    Lutz Beckmann
    Media with 1,3-1,4- , -glucans as selective markers were used for isolation of non-starch-polysaccharide (NSP) degrading bacteria from the intestinal tract of broiler chicken. Formerly unknown 1,3-1,4- , endoglucanase activities in various bacterial species were identified in this study. E. faecium , Streptococcus , Bacteroides and Clostridium strains seem to be responsible for degradation of mixed linked , -glucans in the small intestine and in the hind gut of chickens. Strict anaerobic bacteria (Bacteroides ovatus , B. uniformis , presumably B. capillosus and Clostridium perfringens ) as well as an unidentified bacterium with 98% 16S rDNA homology to an uncultered chicken cecum bacterium were isolated. Additionally, Streptococcus bovis with 1,3-1,4- , -endoglucanase activity was also detected. Different 1,3-1,4- , -endoglucanase activity profiles were observed in SDS/PAGE zymograms. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Experimental exposure of zebrafish, Danio rerio (Hamilton), to Mycobacterium marinum and Mycobacterium peregrinum reveals the gastrointestinal tract as the primary route of infection: a potential model for environmental mycobacterial infection

    M J Harriff
    Abstract The natural route by which fish become infected with mycobacteria is unknown. Danio rerio (Hamilton) were exposed by bath immersion and intubation to Mycobacterium marinum and Mycobacterium peregrinum isolates obtained from diseased zebrafish. Exposed fish were collected over the course of 8 weeks and examined for the presence of mycobacteriosis. Mycobacteria were consistently cultured from the intestines, and often from the livers and spleens of fish exposed by both methods. Mycobacteria were not observed in the gills. Histological analysis revealed that fish infected with M. marinum often developed granulomas accompanied by clinical signs of mycobacteriosis, while infection with M. peregrinum infrequently led to clinical signs of disease. Passage of the bacteria through environmental amoebae (Acanthamoeba castellani) was associated with increased growth of M. peregrinum over the course of 8 weeks, when compared to infection with the bacteria not passed through amoebae. The results provide evidence that zebrafish acquire mycobacteria primarily through the intestinal tract, resulting in mycobacterial dissemination. [source]

    Equivocal Colonic Carcinogenicity of Aloe arborescens Miller var. natalensis Berger at High-Dose Level in a Wistar Hannover Rat 2-y Study

    M. Yokohira
    ABSTRACT:, A 2-y carcinogenicity study of Aloe, Aloe arborescens Miller var. natalensis Berger, a food additive, was conducted for assessment of toxicity and carcinogenic potential in the diet at doses of 4% or 0.8% in groups of male and female Wistar Hannover rats. Both sexes receiving 4% showed diarrhea, with loss of body weight gain. The survival rate in the 4% female group was significantly increased compared with control females after 2 y. Hematological and biochemical examination showed increase of RBC, Hb, and Alb in the 4% males. The cause of these increases could conceivably have been dehydration through diarrhea. AST and Na were significantly decreased in the males receiving 4%, and Cl was significantly decreased in both 4% and 0.8% males. A/G was significantly increased in the 4% females, and Cl was significantly decreased (0.8%) in the female group. Histopathologically, both sexes receiving 4% showed severe sinus dilatation of ileocecal lymph nodes, and yellowish pigmentation of ileocecal lymph nodes and renal tubules. Adenomas or adenocarcinomas in the cecum, colon, and rectum were observed in 4% males but not in the 0.8% and control male groups. Similarly, in females, adenomas in the colon were also observed in the 4% but not 0.8% and control groups. In conclusion, Aloe, used as a food additive, exerted equivocal carcinogenic potential at 4% high-dose level on colon in the 2-y carcinogenicity study in rats. Aloe is not carcinogenic at nontoxic-dose levels and that carcinogenic potential in at 4% high-dose level on colon is probably due to irritation of the intestinal tract by diarrhea. [source]

    Synthesis and Bioaccessibility of Fe-Pheophytin Derivatives from Crude Spinach Extract

    R.E. Nelson
    ABSTRACT:, Heme iron is recognized as a highly bioavailable source of iron suitable for treatment of iron deficiency anemia. However, the animal origin of purified heme limits its broad applicability due to religious, personal, and food safety issues. Development of chlorophyll-derived heme mimetics offers opportunities to expand current iron fortification strategies. The objective of this study was the synthesis of Fe-pheophytin (FePhe) derivatives from natural chlorophyll and subsequent evaluation of their digestive behavior and bioaccessibility in vitro. FePhe a and a, were synthesized from crude spinach extracts by treatment with 1.3 M iron(II)chloride and 0.25 M Na-acetate dissolved in glacial acetic acid at 80 °C for 30 min. FePhe-rich extracts (approximately 1 mM) were formulated into corn starch based test meals (7.5% lipid) and subjected to a 2-step in vitro digestion designed to simulate in vivo gastric and small intestinal conditions. Recovery of FePhe following digestion and transfer of FePhe and pheophytins (Phe) from test meal matrix to mixed micelles was assessed by RP C18-HPLC to determine the digestive stability and micellarization efficiency (bioaccessibility). FePhe a and a, derivatives were moderately stable to digestive conditions with recoveries of 52.3% and 58.7%, respectively. Residual Phe a was stable to digestion. Micellarization efficiency of FePhe a (4%) and a, (3.4%) was significantly (P < 0.05) lower than Phe a (25.8%) from test meals. While digestive stability and micellarization efficiency are limiting, the presence of lipophilic FePhe derivatives in mixed micelles suggests that these compounds would be available for subsequent absorption in the intestinal tract. [source]

    Isolation and Characterization of Lactobacillus Species Having Potential for Use as Probiotic Cultures for Dogs

    S. McCoy
    ABSTRACT:, The need to control pathogenic microorganisms in the intestinal tract of dogs is a growing concern. There is interest in using probiotics such as species of Lactobacillus to help control canine intestinal infections. For successful use as a probiotic, the bacterial species should be of canine intestinal origin since these species exhibit host specificity. Serial dilutions of freshly voided dog feces were plated on Lactobacillus selection (LBS) agar to isolate the cultures. Isolates were identified based on Gram stain, catalase test, and fermentation patterns using API 50 CH kits. All potential isolates were compared for bile resistance based on relative ability to grow in broth containing 0.3% Oxgall, the ability to inhibit Salmonella Typhimurium in associative broth cultures, and the production of reuterin. Of the lactobacilli isolated, Lactobacillus reuteri was the dominant species. However, some cultures of L. acidophilus also were isolated. We found variations among the isolates of L. reuteri and L. acidophilus with respect to bile tolerance. In general, isolates of L. reuteri appeared to be more bile resistant than were isolates of L. acidophilus. There were also variations in the ability to inhibit growth of S. Typhimurium. Some isolates of L. reuteri produced reuterin while others did not. [source]

    Influence of urease activity in the intestinal tract on the results of 13C-urea breath test

    Yoshihisa Urita
    Abstract Background and Aim:, A late rise in 13CO2 excretion in the 13C-urea breath test (UBT) should be found when the substrate passes rapidly through the stomach and makes contact with the colonic bacteria. The aim of this study was to evaluate the influence of intestinal urease activity on the results of the UBT. Method:, A total of 143 subjects who were diagnosed as Helicobacter pylori negative by serology, histology and rapid urease test were recruited. At the end of endoscopy, the tip of the endoscope was placed to the second part of the duodenum and 20 mL of water containing 100 mg of 13C-urea was sprayed into the duodenum. Breath samples were taken at baseline and at 5, 10, 20, 30 and 60 min after administration. Results:, Of 143 subjects, breath ,13CO2 values higher than 2.5, were detected in six (4.2%), four (2.8%) and five (3.5%) subjects at 20, 30 and 60 min, respectively. There was no subject with high ,13CO2 values at 5 and 10 min. Only one subject had an immediate rise at 60 min. Conclusion:, Variability derived from urease activity in the intestinal tract appears to be minimal up to 60 min after ingestion of the test urea. [source]

    Profile of P-glycoprotein distribution in the rat and its possible influence on the salbutamol intestinal absorption process

    Belén Valenzuela
    Abstract The intrinsic absorption of salbutamol in different intestinal segments of the rat was measured and related with the corresponding intestinal P-glycoprotein (P-gp) expression levels. The apparent absorption rate constants (ka, h,1) observed in each fraction by means of the "in situ" rat gut absorption method after perfusion of a 0.29-mM isotonic solution of salbutamol were used as absorption indexes. In a separate series of studies, a semiquantitative analysis of the mRNA expression of P-gp by means of polymerase chain reaction and Western blot with an antibody raised against the P-gp were also performed. The "in situ" ka values determined in the different segments (h,1) showed that the absorption is not homogeneous along the intestinal tract, that is, 0.499,±,0.054 for colon, 0.474,±,0.052 for the proximal segment, 0.345,±,0.014 for the mean, and 0.330,±,0.023 for the distal fraction. Addition of verapamil to the perfusion fluid did provide a better absorption of salbutamol in the distal segment. The analysis of the mRNA expression and levels of P-gp showed that the enzyme content in each section of the intestine was inversely related to salbutamol absorption. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:1641,1648, 2004 [source]

    Taurocholic acid-induced secretion in normal and cystic fibrosis mouse ileum

    J. Hardcastle
    Bile acids cause secretion throughout the intestinal tract and this process contributes to maintaining the fluidity of intestinal contents. In cystic fibrosis (CF) defective intestinal secretion can lead to excessive dehydration of the luminal contents and the development of clinical symptoms. This study was designed to investigate bile acid-induced secretion in mouse ileum and to determine whether this process was defective in CF. Taurocholic acid-induced secretion was monitored as a rise in short-circuit current (SCC) in ileal sheets from normal (Swiss MF1) and transgenic CF mice. Taurocholic acid increased the SCC in both intact and stripped ileal sheets from Swiss MF1 mice. This effect was due to a stimulation of electrogenic Cl, secretion as it was inhibited by Cl, -free conditions, serosal furosemide (frusemide), mucosal diphenylamine-2-carboxylic acid (DPC) and increased serosal K+ concentration, without being affected by reduced mucosal Na+ concentration. Taurocholic acid-induced secretion was inhibited by tetrodotoxin, indicating the involvement of a neural pathway, but this did not include capsaicin-sensitive afferent neurons or muscarinic cholinoreceptors. Mucosal mast cells also contributed to the response. Responses in tissues from transgenic wild-type mice were similar to those obtained with Swiss MF1 animals, but ilea from CF mice exhibited a lower basal SCC with significantly reduced secretory responses to acetylcholine and taurocholic acid. We concluded that taurocholic acid induces ileal secretion by a mechanism that entails activation of enteric nerves and degranulation of mucosal mast cells. Impaired bile acid-induced secretion in CF may contribute to luminal dehydration. [source]

    Oral administration of lactobacilli from human intestinal tract protects mice against influenza virus infection

    M. Kawase
    Abstract Aims:, Our study was conducted to evaluate the potent protective effects of oral administration of probiotic Lactobacillus strains against influenza virus (Flu) infection in a mouse model. Method and Results:, Lyophilized Lactobacillus rhamnosus GG (LGG) and Lactobacillus gasseri TMC0356 (TMC0356) were orally administered to BALB/c mice for 19 days. The test mice were intranasally infected with Flu A/PR/8/34 (H1N1) on day 14, and any changes in clinical symptoms were monitored. After 6 days of infection, the mice were killed and pulmonary virus titres were determined. The clinical symptom scores of mice administered oral LGG and TMC0356 were significantly ameliorated, compared to those of the control mice (P < 0·01). The pulmonary virus titres of the mice fed LGG and TMC0356 were also significantly decreased compared to those of control mice (P < 0·05). Conclusions:, These results indicate that oral administration of lactobacilli, such as LGG and TMC0356, might protect a host animal against Flu infection. Significance and Impact of the Study:, These results demonstrate that oral administration of selected lactobacilli might protect host animals from Flu infection by interactions with gut immunity. [source]

    Identification of Oxalobacter formigenes in the faeces of healthy cats

    J.S. Weese
    Abstract Aims:,Oxalobacter formigenes is an oxalate-degrading intestinal bacterium that has been found in humans, cattle, sheep, rats and dogs. Its presence in the intestinal tract may be a protective factor against calcium oxalate urolithiasis because of its ability to degrade oxalate. The objective of this study was to determine whether O. formigenes could be detected in the faeces of healthy cats. Methods and Results:, A convenience sample of 28 cats was enrolled. Faecal samples were tested for oxc, a gene specific for O. formigenes, by real-time PCR. This gene was detected in 5/28 (18%) cats; however, the prevalence increased to 86% (24/28) with a modification of the methodology. Conclusions:, Demonstrating the presence of O. formigenes in the faeces of healthy cats for the first time in this study. Significance and Impact of the Study:, Future investigation of the role of this organism in the pathophysiology of calcium oxalate urolithiasis in cats is indicated. [source]

    The role of selective digestive decontamination for reducing infection in patients undergoing liver transplantation: A systematic review and meta-analysis,

    Nasia Safdar
    Selective digestive decontamination (SDD) refers to the use of antimicrobials to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract to prevent infections caused by these organisms. Liver transplant patients are highly vulnerable to bacterial infection particularly with gram-negative organisms within the first month after transplantation, and SDD has been proposed as a potential measure to prevent these infections. However, the benefit of this procedure remains controversial. We undertook a systematic review and meta-analysis to determine whether SDD is beneficial in reducing infections overall and those caused by gram-negative bacteria in patients following liver transplantation. All studies that evaluated the efficacy of SDD in liver transplant patients were included. Randomized trials that included liver transplant patients given SDD versus either placebo or no treatment or minimal treatment (e.g., oral nystatin alone), and that provided adequate data to calculate a relative risk ratio, were included in the meta-analysis. Our review shows that most studies found SDD to be effective in reducing gram-negative infection. The nonrandomized and uncontrolled trials also showed benefit with SDD in reducing overall infection; however, the effect on overall infection was limited in the 4 randomized trials, in which the pooled relative risk was 0.88 (95% CI, 0.7-1.1), indicating no statistically significant reduction in infection with the use of SDD. The summary risk ratio for the association between SDD and gram-negative infection was 0.16 (95% CI, 0.07-0.37), indicating an 84% relative risk reduction in the incidence of infection caused by gram-negative bacteria in patients receiving SDD in randomized trials. In conclusion, the available literature supports a beneficial effect of SDD on gram-negative infection following liver transplantation; however, the risk of antimicrobial resistance must be considered. Larger multicenter randomized trials in this patient population to assess the effect of SDD in reducing infection and mortality, while assessing the risk of antimicrobial resistance, are needed. (Liver Transpl 2004;10:817,827.) [source]

    T cell-mediated immunoregulation in the gastrointestinal tract

    ALLERGY, Issue 4 2009
    L. Saurer
    In the intestinal tract, only a single layer of epithelial cells separates innate and adaptive immune effector cells from a vast amount of antigens. Here, the immune system faces a considerable challenge in tolerating commensal flora and dietary antigens while preventing the dissemination of potential pathogens. Failure to tightly control immune reactions may result in detrimental inflammation. In this respect, ,conventional' regulatory CD4+ T cells, including naturally occurring and adaptive CD4+ CD25+ Foxp3+ T cells, Th3 and Tr1 cells, have recently been the focus of considerable attention. However, regulatory mechanisms in the intestinal mucosa are highly complex, including adaptations of nonhaematopoietic cells and innate immune cells as well as the presence of unconventional T cells with regulatory properties such as resident TCR,, or TCR,, CD8+ intraepithelial lymphocytes. This review aims to summarize the currently available knowledge on conventional and unconventional regulatory T cell subsets (Tregs), with special emphasis on clinical data and the potential role or malfunctioning of Tregs in four major human gastrointestinal diseases, i.e. inflammatory bowel diseases, coeliac disease, food allergy and colorectal cancer. We conclude that the clinical data confirms some but not all of the findings derived from experimental animal models. [source]

    Involvement of endotoxin in the mortality of mice with gut-derived sepsis due to methicillin-resistant Staphylococcus aureus

    Masashi Uramatsu
    ABSTRACT MRSA causes a wide diversity of diseases, ranging from benign skin infections to life-threatening diseases, such as sepsis. However, there have been few reports of the pathophysiology and mechanisms of sepsis resulting from the gut-derived origin of MRSA. Therefore, we established a murine model of gut-derived sepsis with MRSA and factors of MRSA sepsis that cause deterioration. We separated mice into four groups according to antibiotic treatment as follows: (i) ABPC 40 mg/kg; (ii) CAZ 80 mg/kg; (iii) CAZ 80 mg/kg + endotoxin 10 ,g/mouse; and (iv) saline-treated control groups. Gut-derived sepsis was induced by i.p. injection of cyclophosphamide after colonization of MRSA strain 334 in the intestine. After the induction of sepsis, significantly more CAZ-treated mice survived compared with ABPC-treated and control groups. MRSA were detected in the blood and liver among all groups. Endotoxin levels were significantly lower in the CAZ-treated group compared to other groups. Inflammatory cytokine levels in the serum were lower in the CAZ-treated group compared to other groups. Fecal culture showed a lower level of colonization of E. coli in the CAZ-treated group compared to other groups. In conclusion, we found that CAZ-treatment ameliorates infection and suppresses endotoxin level by the elimination of E. coli from the intestinal tract of mice. However, giving endotoxin in the CAZ-treated group increased mortality to almost the same level as in the ABPC-treated group. These results suggest endotoxin released from resident E. coli in the intestine is involved in clinical deterioration resulting from gut-derived MRSA sepsis. [source]