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Intestinal Flora (intestinal + flora)
Selected AbstractsBacterial antigens alone can influence intestinal barrier integrity, but live bacteria are required for initiation of intestinal inflammation and injuryINFLAMMATORY BOWEL DISEASES, Issue 6 2006Beate C. Sydora PhD Abstract Intestinal flora plays a critical role in the initiation and perpetuation of inflammatory bowel disease. This study examined whether live fecal bacteria were necessary for the initiation of this inflammatory response or whether sterile fecal material would provoke a similar response. Three preparations of fecal material were prepared: (1) a slurry of live fecal bacteria, (2) a sterile lysate of bacterial antigens, and (3) a sterile filtrate of fecal water. Each preparation was introduced via gastric gavage into the intestines of axenic interleukin-10 gene-deficient mice genetically predisposed to develop inflammatory bowel disease. Intestinal barrier integrity and degrees of mucosal and systemic inflammations were determined for each preparation group. Intestinal barrier integrity, as determined by mannitol transmural flux, was altered by both live fecal bacterial and sterile lysates of bacterial antigens, although it was not altered by sterile filtrates of fecal water. However, only live fecal bacteria initiated mucosal inflammation and injury and a systemic immune response. Fecal bacterial antigens in the presence of live bacteria and sterile fecal bacterial antigens have different effects on the initiation and perpetuation of intestinal inflammation. [source] Intestinal flora in very low-birth weight infantsACTA PAEDIATRICA, Issue 11 2009Markus V. Björkström Abstract Aim:, To study the early faecal microbiota in very low-birth weight infants (VLBW, <1500 g), possible associations between faecal microbiota and faecal calprotectin (f-calprotectin) and to describe the faecal microbiota in cases with necrotizing enterocolitis (NEC) before diagnosis. Methods:, Stool samples from the first weeks of life were analysed in 48 VLBW infants. Bacterial cultures were performed and f-calprotectin concentrations were measured. In three NEC cases, cultures were performed on stool samples obtained before diagnosis. Results:, Bifidobacteria and lactobacilli were often identified in the first stool sample, 55% and 71% of cases, respectively within the first week of life. A positive correlation between lactic acid bacteria (LAB) and volume of enteral feed was found. Other bacteria often identified were Escherichia coli, Enterococcus and Staphyloccus sp. F-calprotectin was not associated with any bacterial species. All NEC cases had an early colonization of LAB. Prior to onset of disease, all cases had a high colonization of non- E. coli Gram-negative species. Conclusion:, In contrast to the previous studies in VLBW infants, we found an early colonization with LAB. We speculate that this may be due to early feeding of non-pasteurized breast milk. [source] Influence of bacitracin on microbial functions in the gastrointestinal tract of horsesEQUINE VETERINARY JOURNAL, Issue 4 2000E. Collinder Summary This study investigated the influence of zinc bacitracin on the intestinal flora of horses. The functionally active intestinal flora was examined in 6 horses during treatment with zinc bacitracin. Utilising gas chromatography, spectrophotometry, gel electrophoresis and paper chromatography, samples were analysed on biochemical markers reflecting the action of parts of the intestinal flora. The following 5 flora-related functions were studied in faecal samples and intestinal samples from different sections of the hindgut: conversion of cholesterol to coprostanol and of bilirubin to urobilinogens, degradation of mucin and of ,-aspartylglycine and inactivation of tryptic activity. Conversion to coprostanol, conversion to urobilinogens and degradation of mucin were affected by treatment of zinc bacitracin and conversion to coprostanol was most sensitive. All functions were normalised in a short time, in contrast to man and rats. Differences in environmental exposures are probably the reason for a more rapid normalisation of the intestinal flora functions in horses. [source] Expression of mitochondrial HMGCoA synthase and glutaminase in the colonic mucosa is modulated by bacterial speciesFEBS JOURNAL, Issue 1 2004Claire Cherbuy The expression of the colonic mitochondrial 3-hydroxy 3-methyl glutaryl CoA (mHMGCoA) synthase, a key control site of ketogenesis from butyrate, is lower in germ-free (GF) than in conventional (CV) rats. In contrast, the activity of glutaminase is higher. The objective of this study was to investigate whether the intestinal flora can affect gene expression through short chain fatty acid (SCFA) and butyrate production. GF rats were inoculated with a conventional flora (Ino-CV) or with a bacterial strain producing butyrate (Clostridium paraputrificum, Ino- Cp) or not (Bifidobacterium breve, Ino- Bb). In the Ino-CV rats, mHMGCoA synthase expression was restored to the CV values 2 days after the inoculation, i.e. concomitantly with SCFA production. In the Ino- Cp group, but not in the Ino- Bb group, mHMGCoA synthase and glutaminase were expressed at the level observed in the CV rats. These data suggest that the intestinal flora, through butyrate production, could control the expression of colonic mHMGCoA synthase and glutaminase. These modifications in gene expression by butyrate in vivo seem unrelated to a modification of histone acetylation. [source] Anti tumour necrosis-, therapy increases the number of FOXP3+ regulatory T cells in children affected by Crohn's diseaseIMMUNOLOGY, Issue 2 2008Ida Ricciardelli Summary Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal tract. Its pathogenesis is not completely understood, though the prevailing model is that the intestinal flora drives a strong intestinal T helper 1 (Th1)/Th17 type immune response and inflammation in the genetically susceptible host. This leads to overly aggressive T-cell responses to normal bacteria causing tissue damage. Intestinal homeostasis and maintenance of tolerance to harmless antigens in the intestine has been shown to be maintained by CD4+ CD25+ T regulatory cells (Treg) in animal models of inflammatory bowel diseases. Here we investigated whether Infliximab, a chimeric monoclonal antibody directed against tumour necrosis factor (TNF)-, shown to be highly effective in the treatment of CD, has any effect on mucosal CD4+ CD25+ (FOXP3+) Tregs. Colonic mucosal biopsies from children with active Crohn's disease treated in vivo with Infliximab and controls were analysed to determine FOXP3 expression by immunofluorescence and reverse transcription,polymerase chain reaction. We observed that FOXP3+ T cells were significantly reduced in mucosa of CD patients with active disease compared with controls and restored to normal following Infliximab treatment. The frequency of FOXP3+ cells and mRNA expression was significantly increased in CD mucosa from patients treated in vivo with Infliximab compared with CD patients treated with conventional therapies. In conclusion, we show that Infliximab treatment does not solely neutralize soluble TNF-,, but also affects activation and possibly expansion of mucosal regulatory T cells. We suggest that anti TNF-, immunotherapy can also restore mucosal homeostasis in Crohn's disease. [source] CD4+CD25+ cell depletion from the normal CD4+ T cell pool prevents tolerance toward the intestinal flora and leads to chronic colitis in immunodeficient miceINFLAMMATORY BOWEL DISEASES, Issue 6 2006Claudia Veltkamp MD Abstract Background: CD4+CD25+ regulatory T cells have been shown to prevent immune-mediated colitis in mice; however, it is unclear whether the absence of CD4+CD25+ in the normal CD4+ T cell pool is responsible for the development of chronic colitis. Using the T cell-deficient Tg,26 mouse model, we show that CD4+CD25, cells but not CD4+CD25+ cells induce a severe intestinal inflammation. Transfer of CD4+CD25+ cells, together with CD4+CD25, cells, ameliorated intestinal inflammation, and reconstitution with the whole mesenteric lymph node cell pool did not induce colitis in recipients. Transferred CD4+CD25, cells were found mainly in the mesenteric lymph nodes, where they showed an activated TH1-like phenotype. In the absence of regulatory CD4+CD25+ T cells, recipient CD4+ cells secreted IFN-, in response to stimulation with intestinal bacterial antigen that was prevented in vivo and in vitro by regulatory CD4+CD25+ cells. These studies suggest that CD4+CD25, cells have a strong colitogenic effect in the Tg,26 colitis model and that CD4+CD25+ cells may be the main regulators that prevent or downregulate the proinflammatory effect of colitogenic T cells in the Tg,26 mouse model. [source] Effect of Pectin Enhancement on Plasma Quercetin and Fecal Flora in Rutin-Supplemented MiceJOURNAL OF FOOD SCIENCE, Issue 9 2007M. Tamura ABSTRACT:, Few reports have considered the effects of dietary fiber on plasma quercetin and the intestinal flora. We investigated the effects of pectin on the plasma and fecal flora of mice fed a diet supplemented with the quercetin glycoside rutin. Male mice were randomly divided into 2 groups, which were fed a pectin,rutin (PR) or cellulose,rutin (CR) diet for 14 d. Plasma quercetin and isorhamnetin metabolites were measured by high-performance liquid chromatography. Feces were immediately processed with bacteriological procedures. The fecal flora was investigated. Plasma quercetin and isorhamnetin concentrations were significantly higher in the PR diet group, as was the plasma isorhamnetin/quercetin ratio. The composition of the intestinal flora differed between the 2 dietary groups. The total number of fecal bacteria was significantly larger in the PR group, in which most types of bacteria were more abundant, with the exceptions of bifidobacteria, fusiform-shaped bacteria, and staphylococci. The lower gut seemed to be the major absorption site for rutin. Pectin might thus enhance the bioavailability of quercetin from rutin by altering the metabolic activity of the intestinal flora and/or gut physiological function. [source] Lactulose as a food ingredientJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 12 2009Agustín Olano Abstract Lactulose is a synthetic ketose disaccharide that can be obtained from lactose by different methods of synthesis. Chemical methods are based on the isomerization of lactose in the presence of basic catalysts and enzymatic methods using lactose as a galactose donor and fructose as an acceptor. The prebiotic properties of lactulose have been known for more than 50 years and numerous studies have confirmed several health benefits of lactulose as a food ingredient, including selective stimulation of intestinal flora, laxative effect and improvement of calcium absorption. Its use in fermented milk manufacture may reduce the incubation period and favour the growth of bifidobacteria. The synthesis of lactulose-derived oligosaccharides may provide a new group of prebiotics with properties complementary to those of native lactulose. Copyright © 2009 Society of Chemical Industry [source] Review article: bifidobacteria as probiotic agents , physiological effects and clinical benefitsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2005C. PICARD Summary Bifidobacteria, naturally present in the dominant colonic microbiota, represent up to 25% of the cultivable faecal bacteria in adults and 80% in infants. As probiotic agents, bifidobacteria have been studied for their efficacy in the prevention and treatment of a broad spectrum of animal and/or human gastrointestinal disorders, such as colonic transit disorders, intestinal infections, and colonic adenomas and cancer. The aim of this review is to focus on the gastrointestinal effects of bifidobacteria as probiotic agents in animal models and man. The traditional use of bifidobacteria in fermented dairy products and the GRAS (,Generally Recognised As Safe') status of certain strains attest to their safety. Some strains, especially Bifidobacterium animalis strain DN-173 010 which has long been used in fermented dairy products, show high gastrointestinal survival capacity and exhibit probiotic properties in the colon. Bifidobacteria are able to prevent or alleviate infectious diarrhoea through their effects on the immune system and resistance to colonization by pathogens. There is some experimental evidence that certain bifidobacteria may actually protect the host from carcinogenic activity of intestinal flora. Bifidobacteria may exert protective intestinal actions through various mechanisms, and represent promising advances in the fields of prophylaxis and therapy. [source] Bacterial infections in cirrhosisLIVER INTERNATIONAL, Issue 4 2004Miguel Navasa Abstract: Spontaneous bacterial peritonitis, urinary tract infections, respiratory infections and bacteremia are the most frequent infective complications in cirrhosis. These infections are due to the concomitant presence of different facilitating mechanisms including changes in the intestinal flora and in the intestinal barrier, depression of activity of the reticuloendothelial system, decreased opsonic activity of the ascitic fluid, neutrophil leukocyte dysfunction and iatrogenic factors among others. The fact, that the probability of having a microorganism responsible for the infection quinolone resistant is higher than 30% should be taken into account when treating any infection in a cirrhotic patient receiving selective intestinal decontamination with quinolones, and therefore, quinolones as empiric treatment are not indicated. [source] Lactobacillus casei rhamnosus Lcr35 in children with chronic constipationPEDIATRICS INTERNATIONAL, Issue 4 2007LING-NAN BU Abstract Background: The purpose of the present paper was to evaluate the efficacy of probiotics (Lactobacillus casei rhamnosus, Lcr35) for treating children with chronic constipation and to compare its effect with magnesium oxide (MgO) and placebo. Methods: This double-blind placebo-controlled, randomized study enrolled 45 children under 10 years old with chronic constipation. They were randomly assigned to receive Lcr35 (8 × 108 c.f.u./day; n = 18), MgO (50 mg/kg/day; n = 18), or placebo (n = 9) orally twice daily for 4 weeks. Lactulose use (1 mL/kg per day) was allowed when no stool passage for 3 days was noted. Glycerin enema was used only when no defecation was noted for >5 days or abdominal pain was suffered due to stool impaction. Bacterial cultures of stool were performed before and after treatment to evaluate the change of intestinal flora. Comparisons of the frequency of defecation, consistency of stool and the use of lactulose or enema during the period of treatment were made among the three groups. Results: The patients who received MgO or probiotics had a higher defecation frequency (P = 0.03), higher percentage of treatment success (P = 0.01), less use of glycerin enema (P = 0.04) and less hard stool (P = 0.01) than the placebo group. There was no significant difference between MgO and probiotic groups in the aforementioned comparisons. The first effect of MgO (second week) on constipation was slightly earlier than that of probiotic (second to third week). Abdominal pain occurred less frequently in the probiotic group than in both the MgO and the placebo groups (P = 0.03). There was no statistically significant difference among the three groups in the use of lactulose, episodes of fecal soiling, and change of appetite. No adverse effect was noted in probiotic and placebo groups. Only one patient in the MgO group suffered from mild diarrhea. Conclusion: Lcr35 was effective in treating children with chronic constipation. There is no statistically significant difference in efficacy between MgO and Lcr35, but less abdominal pain occurred when using Lcr35. Study with larger case number and longer follow up is needed in the future. [source] Fecal bacterial diversity of human-habituated wild chimpanzees (Pan troglodytes schweinfurthii) at Mahale Mountains National Park, Western TanzaniaAMERICAN JOURNAL OF PRIMATOLOGY, Issue 7 2010Brian A. Szekely Abstract Although the intestinal flora of chimpanzees has not been studied, insight into this dynamic environment can be obtained through studies on their feces. We analyzed fecal samples from human-habituated, wild chimpanzees at Mahale Mountains National Park, Tanzania, and compared microbial community profiles to determine if members of the same social group were similar. Between July and December 2007, we collected fresh fecal samples from 12 individuals: four juveniles, four adolescents, and four adults, including three parent,offspring pairs. Each sample was analyzed using Terminal-Restriction Fragment Length Polymorphism of amplified 16S rRNA genes. Twelve different profiles were generated, having between 1 and 15 Terminal-Restriction Fragments (T-RFs). Overall, a total of 23 different T-RFs were produced. Putative assignments of T-RFs corresponded to the phyla Firmicutes (Clostridia, Bacilli, and Lactobacilli), Bacteroidetes, Tenericutes (Mollicutes Class), Actinobacteria, and Proteobacteria, as well as to uncultured or unidentified organisms. Firmicutes and Bacteroidetes phyla and Mollicutes Class were the most commonly assigned in 11, 8, and 8 of the samples, respectively, with this being the first report of Mollicutes in wild chimpanzees. Principal Components Analysis (PCA) revealed clustering of nine samples, and 80.5% of the diversity was accounted for by three samples. Morisita indices of community similarity ranged between 0.00 and 0.89, with dissimiliarity (<0.5) between most samples when compared two at a time. Our findings suggest that, although phylotypes are common among individuals, profiles among members of the same social group are host-specific. We conclude that factors other than social group, such as kinship and age, may influence fecal bacterial profiles of wild chimpanzees, and recommend that additional studies be conducted. Am. J. Primatol. 72:566,574, 2010. © 2010 Wiley-Liss, Inc. [source] Lactobacillus hayakitensis, L. equigenerosi and L. equi, predominant lactobacilli in the intestinal flora of healthy thoroughbredsANIMAL SCIENCE JOURNAL, Issue 3 2009Hidetoshi MORITA ABSTRACT To detect the predominant lactobacilli in the intestinal flora of healthy thoroughbreds, we isolated lactobacilli from the feces of nine thoroughbreds (five males and four females; 0,15-year-old). The isolated lactobacilli comprise 17 species (37 strains), and they were classified into five groups: Lactobacillus salivarius (6 species), L. reuteri (6 species), Lactobacillus delbrueckii (3 species), L. buchneri (1 species) and L. vitulinus (1 species). On the basis of 16S rRNA gene sequences, we identified 3 other phylogenetic relatives belonging to the genus Lactobacillus. These results suggest that the intestinal flora of thoroughbreds may comprise many species of the genus Lactobacillus. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analyses of the 340-bp fragments of the 16S rRNA genes from the same nine fecal samples showed that L. hayakitensis, L. equigenerosi and L. equi are contained in all the samples, suggesting that these species are predominant lactobacilli in the intestinal flora of thoroughbreds. [source] Dietary nucleic acids promote a shift in Th1/Th2 balance toward Th1-dominant immunityCLINICAL & EXPERIMENTAL ALLERGY, Issue 7 2000Sudo Background Dietary sources of nucleic acids and their relative components are known to affect host immune function; however, it has not yet been clarified whether such dietary nucleic acids influence the pathogenesis of allergic reaction. Objective The purpose of this study is to elucidate the effect of dietary nucleic acids on Th1/Th2 balance. Methods Both human flora-associated and specific pathogen-free BALB/c mice were maintained on either nucleic acid-free, or -supplemented diets. The effects of nucleic acids on both in vivo antibody levels and in vitro splenocyte cytokine production were compared using these mice. Results Supplementation of nucleic acids caused a reduction in the serum antibody levels of total IgM, IgG, IgG1, and IgE in the human flora-associated mice without affecting the composition of intestinal flora. In contrast, there was no significant difference of the serum IgG2a levels between nucleic acid-free and -supplemented mice. Such a phenomenon as that, the supplementation of dietary nucleic acids reduces the serum IgE or IgG1 levels, but not the IgG2a level, was also seen in the specific pathogen free mice. Moreover, when the mice were systematically challenged with ovalbumin, the supplementation of nucleic acids also suppressed the serum ovalbumin-specific IgE and IgG1 antibody levels as well as in vitro IL-4 and IL-10 secretion, while enhancing both the serum ovalbumin-specific IgG2a antibody levels and in vitro IFN , secretion. Conclusion These results suggested that dietary nucleic acids may play an important role in promoting a shift in Th1/Th2 balance toward Th1-dominant immunity. [source] | ||||||||||||||||