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Intestinal Microflora (intestinal + microflora)
Selected AbstractsTLR2-independent induction and regulation of chronic intestinal inflammationEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 2 2010Olivier Boulard Abstract Interactions between the intestinal microflora and host innate immune receptors play a critical role in intestinal homeostasis. Several studies have shown that TLR2 can modulate inflammatory responses in the gut. TLR2 signals enhance tight junction formation and fortify the epithelial barrier, and may play a crucial role in driving acute inflammatory responses towards intestinal bacterial pathogens. In addition, TLR2 agonists can have direct effects on both Th1 cells and Treg. To define the role of TLR2 in the induction and regulation of chronic intestinal inflammation we examined the effects of TLR2 deletion on several complementary models of inflammatory bowel disease. Our results show that TLR2 signals are not required for the induction of chronic intestinal inflammation by either innate or adaptive immune responses. We further show that TLR2,/, mice harbor normal numbers of Foxp3+ Treg that are able to suppress intestinal inflammation as effectively as their WT counterparts. We also did not find any intrinsic role for TLR2 for pathogenic effector T-cell responses in the gut. Thus, in contrast to their role in acute intestinal inflammation and repair, TLR2 signals may have a limited impact on the induction and regulation of chronic intestinal inflammation. [source] Usage of Aplysia lectin interactions with T antigen and poly- N -acetyllactosamine for screening of E. coli strains which bear glycoforms cross-reacting with cancer-associated antigensFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2001Nechama Gilboa-Garber Abstract Aplysia gonad lectin (AGL), which strongly agglutinates cancer cells, was found, in the present study, to bind to erythrocyte T antigen, in addition to its affinity to Ii system antigens. These antigens were reported to be overexpressed and to contribute to tumor progression and invasion. In healthy human sera, there are antibodies against them, stimulated by the normal intestinal microflora, which bear similar glycoforms. Since the levels of these antibodies were reported to be lower in most cancer patients' sera, we have examined the applicability of AGL to isolation of enteric commensal Escherichia coli strains which bear glycoforms cross-reacting with the cancer-associated antigens. Among 30 E. coli isolates examined, two were agglutinated by AGL. One of them was also agglutinated by certain related galactophilic lectins, which bind to the T and Tn antigens. The agglutination of the two bacteria by healthy human sera, as a group, was stronger than that displayed by the cancer patients' sera. These results indicate that AGL might be useful for identification of the desired bacteria, which could potentially serve for cancer diagnosis and therapy. [source] Molecular mechanisms of portal vein toleranceHEPATOLOGY RESEARCH, Issue 5 2008Tomohiro Watanabe The liver has been considered as a tolerogenic organ in the sense that favors the induction of peripheral tolerance. The administration of antigens (Ags) via the portal vein causes tolerance, which is termed portal vein tolerance and can explain the occurrence of tolerogenic responses in the liver. Here we discuss the fundamental mechanisms accounting for portal vein tolerance. Antigen-presenting cells (APCs) in the liver, especially dendritic cells and sinusoidal endothelial cells, have limited the ability to produce pro-inflammatory cytokines upon stimulation with endotoxin, an effect that could be due to the continuous exposure to bacterial Ags derived from intestinal microflora. Ag presentation by liver APCs results in T cell tolerance through clonal deletion and selection of regulatory T cells. Thus, APCs with immunosuppressive functions are associated with the achievement of portal vein tolerance via the induction of clonal deletion and generation of regulatory T cells. [source] Prebiotics in chronic intestinal inflammationINFLAMMATORY BOWEL DISEASES, Issue 3 2009Mirjam A.C. Looijer, Van Langen MD Abstract Prebiotics are nondigestible fermentable fibers that are reported to have health benefits for the host. Older as well as more recent studies show beneficial effects in experimental colitis and lately also in human inflammatory bowel diseases (IBD), such as Crohn's disease, ulcerative colitis, and chronic pouchitis. In this review we give an overview of the benefits of prebiotics in rodent IBD models and in IBD patients and discuss their possible protective mechanisms. Commensal intestinal bacteria induce and perpetuate chronic intestinal inflammation, whereas others are protective. However, most of the current medications are directed against the exaggerated proinflammatory immune response of the host, some of them toxic and costly. Feeding prebiotics changes the composition of the intestinal microflora toward more protective intestinal bacteria and alters systemic and mucosal immune responses of the host. Therapy for IBD targeting intestinal bacteria and their function is just emerging. Prebiotics have the promise to be relatively safe, inexpensive, and easy to administer. Unraveling their protective mechanisms will help to develop rational applications of prebiotics. However, the initial promising results with dietary prebiotics in preclinical trials as well as small studies in human IBD will need to be confirmed in large randomized controlled clinical trials. (Inflamm Bowel Dis 2008) [source] Early bacterial dependent induction of inducible nitric oxide synthase (iNOS) in epithelial cells upon transfer of CD45RBhigh CD4+ T cells in a model for experimental colitisINFLAMMATORY BOWEL DISEASES, Issue 12 2007Gerard Dijkstra MD Abstract Background: Both the role of inducible nitric oxide synthase (iNOS) in the development of inflammatory bowel disease (IBD) as well as the molecular details governing its mucosal induction remain unclear. Methods: In the present study we evaluated the role of the residing intestinal microflora in the induction of epithelial iNOS upon transfer of CD45RBhigh CD4+ T cells to SCID mice. CB-17 SCID mice were reared with conventional flora (CNV) or germfree CB-17 SCID mice were monoassociated with Helicobacter muridarum, act A(,) mutant Listeria monocytogenes, segmented filamentous bacteria (SFB), or Ochrobactrum anthropi. Results: Within 2 weeks CNV SCID mice injected with CD45RBhigh CD4+ T cells showed a focal, epithelial iNOS expression on the apical site of villi that preceded the infiltration of CD4+ T cells and cytokine production followed by extension of this expression to the entire surface along the whole crypt axis as the colitis progressed. SCID mice monoassociated with H. muridarum developed a severe colitis and showed high epithelial iNOS expression. CNV-SCID mice without T cells and SCID mice monoassociated with SFB did not show any iNOS expression, whereas SCID mice monoassociated with act A(,) mutant L. monocytogenes and O. anthropi showed some scattered epithelial iNOS staining on the apical site of a few villi, but none of these mice developed colitis. Conclusions: These findings demonstrate that the expression of epithelial iNOS is highly bacterium-specific and correlates with the severity of disease, suggesting an important role for this enzyme in the development of IBD. (Inflamm Bowel Dis 2007) [source] Bacterial population analysis of human colon and terminal ileum biopsies with 16S rRNA-based fluorescent probes: Commensal bacteria live in suspension and have no direct contact with epithelial cellsINFLAMMATORY BOWEL DISEASES, Issue 10 2005Laurens A van der Waaij PhD Abstract Background: The commensal intestinal microflora has important metabolic and perhaps also immune modulatory functions. Evidence has accumulated that the microflora plays a role in the pathogenesis of inflammatory bowel disease. Therefore, there is a growing interest in the intestinal microflora and its interaction with the host. Presumably, this interaction takes place at the mucus layer. In this study, we investigated the microflora that is present at the mucus layer and addressed the following questions. Does a specific mucus-adherent microflora exist? Is there direct contact between commensal bacteria and epithelial cells? Methods: Snap-frozen biopsies were taken of 5 colon regions and of the terminal ileum in 9 subjects with a normal colon. Fecal samples were also collected. Bacteria were detected in cryosections with fluorescent in situ hybridization (FISH) with 16S ribosomal (r)RNA-targeted probes for all bacteria and specific probes for the major representatives of anaerobic microflora (bifidobacteria, Bacteroides, clostridia, atopobia) and aerobic microflora (Enterobacteriaceae, enterococci, streptococci, lactobacilli). Results: With this sensitive technique, bacteria were only observed at the luminal side of the intestinal mucus layer. Very few microcolonies were present at the mucus layer, and the composition of the bacterial microflora present in the feces was similar to that at the mucus layer of the terminal ileum and colon regions. Conclusions: We did not observe direct contact between bacteria and epithelial cells. The equal distribution of bacterial species suggests that intestinal commensal bacteria live in suspension in the lumen and that there is no specific mucus-adherent microflora. [source] Circulating enterolactone and prostate cancer risk: A Nordic nested case-control studyINTERNATIONAL JOURNAL OF CANCER, Issue 1 2002Pär Stattin Abstract Enterolactone, a phytoestrogen belonging to the class of lignans, is produced by the intestinal microflora from precursors in plant foods and has been implicated in protection against cancer. We study the effect of enterolactone on the risk of a subsequent diagnosis of prostate cancer. We conducted a longitudinal, nested case-control study by linkage of 3 biobanks to the cancer registries in Finland, Norway and Sweden, respectively. Enterolactone concentrations were measured by time-resolved fluoroimmunoassay in serum from 794 men who had a diagnosis of prostate cancer at a mean follow-up time of 14.2 years after blood collection and among 2,550 control men matched within each cohort for age (±2 years), date of blood collection (±2 months) and county. The median enterolactone concentrations did not differ between case and control subjects in the full study group (8.4 nmol/L [25th,75th percentile = 4.5,15.0] vs. 8.5 nmol/L [25th,75th percentile = 4.3,15.9]), nor in the national groups. Odds ratios of prostate cancer risk estimated by conditional logistic regression for increasing concentrations of enterolactone in quartiles in the full study group were 1.00 (referent), 1.21 (95% confidence interval [CI] = 0.96,1.52), 1.16 (95% CI = 0.91,1.47) and 1.08 (95% CI = 0.83,1.39). The OR estimate for the highest vs. the lowest quartile of enterolactone in separate analyses of the Norwegian, Finnish and Swedish cohort was 1.21 (95% CI = 0.91,1.60), 1.02 (95% CI = 0.59,1.76) and 0.87 (95% CI = 0.45,1.67), respectively. No support for the hypothesis that high circulating enterolactone is protective against prostate cancer was found. © 2002 Wiley-Liss, Inc. [source] Detection and distribution of probiotic Escherichia coli Nissle 1917 clones in swine herds in GermanyJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2006S. Kleta Abstract Aims:, To verify the presence of Escherichia coli Nissle 1917 as a natural isolate in swine and to characterize in vitro probiotic properties as well as in vivo persistence in a feeding experiment. Methods and Results:, During studies on the intestinal microflora of pigs, we isolated E. coli Nissle 1917 sporadically from a pig population over a period of 1 year. The identity of the isolates as E. coli Nissle 1917 was verified by serotyping, Nissle-specific PCR, macrorestriction analysis (pulsed field gel electrophoresis) and the determination of in vitro probiotic properties in invasion and adhesion assays using a porcine intestinal epithelial cell line. Both the E. coli isolates and the E. coli Nissle 1917 strain showed strong reductions in adhesion of porcine enteropathogenic E. coli and invasion of Salmonella typhimurium with epithelial cells in vitro, with a probiotic effect. Screening of five epidemiologically unlinked swine farms and two wild boar groups showed one farm positive for E. coli Nissle 1917. A feeding experiment with four piglets showed viable E. coli Nissle 1917 in the intestine of three animals. Conclusions:, The results of this study suggest that the E. coli Nissle 1917 strain is already partially established in swine herds, but the colonization of individual animals is variable. Significance and Impact of the Study:, We report natural, long-term colonization and transmission of the probiotic E. coli Nissle 1917 strain in a swine herd, characterized individual persistence and colonization properties in swine and established an in vitro porcine intestinal epithelial cell model of probiotic action. The results of this study would have implications in the use of this strain as a probiotic in swine and contribute to a better understanding of the individual nature of intestinal bacterial persistence and establishment. [source] Raw potato starch and short-chain fructo-oligosaccharides affect the composition and metabolic activity of rat intestinal microbiota differently depending on the caecocolonic segment involvedJOURNAL OF APPLIED MICROBIOLOGY, Issue 2 2003G.M. Le Blay Abstract Aims:In vitro studies have suggested that fructo-oligosaccharides (FOS) and resistant starch (two fermentable non-digestible carbohydrates) display different fermentation kinetics. This study investigated whether these substrates affect the metabolic activity and bacterial composition of the intestinal microflora differently depending on the caecocolonic segment involved. Methods and Results: Eighteen rats were fed a low-fibre diet (Basal) or the same diet containing raw potato starch (RPS) (9%) or short-chain FOS (9%) for 14 days. Changes in wet-content weights, bacterial populations and metabolites were investigated in the caecum, proximal and distal colon and faeces. Both substrates exerted a prebiotic effect compared with the Basal diet. However, FOS increased lactic acid-producing bacteria (LAPB) throughout the caecocolon and in faeces, whereas the effect of RPS was limited to the caecum and proximal colon. As compared with RPS, FOS doubled the pool of caecal fermentation products, while the situation was just the opposite distally. This difference was mainly because of the anatomical distribution of lactate, which accumulated in the caecum with FOS and in the distal colon with RPS. Faeces reflected these impacts only partly, showing the prebiotic effect of FOS and the metabolite increase induced by RPS. Conclusions: This study demonstrates that FOS and RPS exert complementary caecocolonic effects. Significance and Impact of the study: The RPS and FOS combined ingestion could be beneficial by providing health-promoting effects throughout the caecocolon. [source] Effect of Yam (Dioscorea alata Compared to Dioscorea japonica) on Gastrointestinal Function and Antioxidant Activity in MiceJOURNAL OF FOOD SCIENCE, Issue 7 2006Cheng-Chin Hsu ABSTRACT:, Effects of Chinese yam (Dioscorea alata) and Japanese yam (Dioscorea japonica) on gastrointestinal functions including intestinal microflora and intestinal enzymes' activities, as well as antioxidant protection against lipopolysaccharide (LPS)-induced oxidative damage, in Balb/cA mice were examined. In part I, mice were fed yam-supplemented diet for 4 or 8 wk, and killed with carbon dioxide. In part II, mice were fed yam-supplemented diet for 4 wk, and followed by intraperitoneal LPS treatment (i.p. 4 mg/kg bodyweight). The intake of Chinese yam and Japanese yam significantly changed intestinal microflora, in which the colony numbers of Bifidobacterium and Lactobacillus were increased and the colony numbers of Clostridium perfringens were decreased (P < 0.05). The intake of both Chinese and Japanese yams also significantly elevated the activity of leucine aminopeptidase and lipase (P < 0.05), and the activities of sucrase and maltase were increased only in 20% yam-treated groups (P < 0.05). The preintake of yam significantly alleviated subsequent LPS-induced oxidative injury by decreasing lipid oxidation level and fibronectin production and elevating superoxide dismutase activity (P < 0.05). Both Chinese and Japanese yams contained dietary fibers, polyphenols, and flavonoids, which may contribute to the observed gastrointestinal function and antioxidant protection. These results suggest that both Chinese yam and Japanese yam were beneficial for intestinal health and oxidation prevention. [source] The anti-allergenic properties of milk kefir and soymilk kefir and their beneficial effects on the intestinal microfloraJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2006Je-Ruei Liu Abstract Food allergy is now recognized as a worldwide problem, and like other atopic disorders its incidence appears to be increasing. Kefir is reported to possess the ability to reduce intestinal permeation of food antigens; however, no experimental study has clearly evaluated the relationships between kefir consumption, allergen-specific IgE response, and intestinal microflora. The aim of this study was to evaluate the effect of oral consumption of milk kefir and soymilk kefir on in vivo IgE and IgG1 production induced by ovalbumin (OVA) in mice. The effects of kefir administration on the murine intestinal microflora were also examined. Oral administration of milk kefir and soymilk kefir for 28 days significantly increased the fecal populations of bifidobacteria and lactobacilli, while it significantly decreased those of Clostridium perfringens. Milk kefir and soymilk kefir also significantly decreased the serum OVA-specific IgE and IgG1 levels for both groups, but not those of the IgG2a analogues. Consumption of milk kefir and soymilk kefir suppressed the IgE and IgG1 responses and altered the intestinal microflora in our supplemented group, suggesting that milk kefir and soymilk kefir may be considered among the more promising food components in terms of preventing food allergy and enhancement of mucosal resistance to gastrointestinal pathogen infection. Copyright © 2006 Society of Chemical Industry [source] Approaches in the safety evaluations of veterinary antimicrobial agents in food to determine the effects on the human intestinal microfloraJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2005C. E. CERNIGLIA The administration of antimicrobial agents to livestock creates potential for antibiotic residues to enter the food supply and be consumed by humans. Therefore, as a process of food animal drug registration, national regulatory agencies and international committees evaluate data regarding the chemical, microbiologic, pharmacokinetic, pharmacodynamic, pharmacologic, toxicologic, and antimicrobial properties of veterinary drugs to assess the safety of ingested antimicrobial residues to consumers. Currently, European, Australian and United States guidelines for veterinary drug registration require a safety assessment of microbiologic hazards from consumption of antimicrobial residues taking into account the potentially adverse effects on human intestinal microflora. The main concerns addressed are selection of resistant bacteria in the gastrointestinal tract and disruption of the colonization barrier of the resident intestinal microflora. Current requirements differ among national agencies. Efforts are ongoing internationally to review and harmonize approaches and test methods and protocols for application to these microbiologic safety evaluations of antimicrobial drug residues in food. This review describes the background to current regulatory approaches used in applying in vitro and in vivo methods to set a microbiologic acceptable daily intake for residues in food derived from animals treated with an antimicrobial agent. This paper also examines the current research needs to support these evaluations. [source] Systematic review: nutritional therapy in paediatric Crohn's diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 4 2008A. S. DAY Summary Background At least 25% of individuals diagnosed with Crohn's disease (CD) have onset of disease in childhood. Almost all children with CD have nutritional impairments, such as weight loss or stunting, at diagnosis or subsequently. Nutritional therapy (exclusive enteral nutrition) is established as a valid and effective treatment in paediatric CD. The advantages of this approach are induction of remission and control of inflammatory changes, mucosal healing, positive benefits to growth and overall nutritional status, and avoidance of other medical therapies. Aim To provide a comprehensive up-to-date review of the roles of nutritional therapy in CD and of the data supporting this therapy. Methods A search of PubMed was performed with search terms ,enteral nutrition', ,nutritional therapy', ,Crohn disease' and ,children'. Relevant articles were selected from this search. In addition, the reference lists of available articles were reviewed for further relevant articles. Results Nutritional therapy offers numerous benefits in the management of CD. Recent work has begun to elucidate the likely mechanisms of this therapy. These include direct mucosal anti-inflammatory effects and alteration of intestinal microflora. Conclusion Further studies are required to define longer-term effects of nutritional therapy in patients with CD. [source] A differential medium for lactic acid-producing bacteria in a mixed cultureLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2008H.M. Lee Abstract Aims:, Modified deMan-Rogosa Sharpe agar containing bromophenol blue (mMRS-BPB) was tested as a medium for counting and differentiation of each lactic acid-producing bacterium (LAB), especially in a mixed culture. Methods and Results:, Type strains of 10 LAB species (Lactobacillus acidophilus, L. brevis, L. bulgaricus, L. gasseri, L. paracasei, L. plantarum, L. reuteri, Weissella confusa, Bifidobacterium bifidum and B. infantis) and five commercial yogurts were inoculated on plate count agar with bromocresol purple, mMRS, and mMRS-BPB. Each type strain showed more clearly formed colonies on the three media under anaerobic conditions than under aerobic conditions. Especially each type strain produced colonies with specific characteristics of each species on mMRS-BPB. Commercial yogurts produced the largest number of colonies with various shapes and colours on mMRS-BPB. Conclusions:, Modified deMan-Rogosa Sharpe agar containing bromophenol blue under anaerobic conditions is appropriate for counting and differentiating each LAB in a mixed culture. Significance and Impact of the Study:, Modified deMan-Rogosa Sharpe agar containing bromophenol blue will be useful in isolation and enumeration of each LAB from fermented foods as well as intestinal microflora. [source] Oral and intestinal microflora in 5-fluorouracil treated rats, translocation to cervical and mesenteric lymph nodes and effects of probiotic bacteriaMOLECULAR ORAL MICROBIOLOGY, Issue 5 2003I. von Bültzingslöwen Serious systemic infections may occur during cancer chemotherapy due to disturbances in the oropharyngeal and gastrointestinal microflora, impaired mucosal barrier functions and immunosuppression. Bacteria may spread from the gastrointestinal tract to the regional lymph nodes. The routes for bacterial spread from the oral cavity are less well known. In the present study we investigated changes in the oral and intestinal microfloras in rats given 50 mg/kg 5-fluorouracil (5-FU) i.v. for 6 days. Bacterial dissemination to the lymph nodes draining the oral cavity and the lymph nodes draining the gastrointestinal tract was examined. Effects of adding the probiotic strain Lactobacillus plantarum 299v in the drinking water to the rats were measured. 5-FU treatment caused an increase in the number of facultative and strictly anaerobic bacteria in biopsies from the oral cavity and an increase in the number of facultative anaerobes in the large intestine. The proportion of facultative gram-negative rods increased in both the oral cavity and intestine. Bacteria translocated to both the cervical and mesenteric lymph nodes in untreated animals and increased in numbers after 5-FU treatment due to an increase in the number of facultative gram-negative rods. Treatment with L. plantarum 299v improved food intake and body weight in 5-FU-treated rats. It also reduced the 5-FU-induced raise in the total numbers of facultative anaerobes in the intestine, but did not reduce translocation and did not prevent diarrhea. This study reinforces the oral cavity, along with the gastrointestinal tract, as a source for bacterial dissemination. The use of probiotic bacteria may reduce some side effects of 5-FU treatment. [source] Exclusive Breast-feeding: Does It Have the Potential to Reduce Breast-feeding Transmission of HIV-1?NUTRITION REVIEWS, Issue 11 2000Melanie M. Smith M.N.S. Exclusive breast-feeding is unambiguously the optimal infant feeding practice and is universally promoted in the absence of human immunodeficiency virus (HIV-1). It is associated with reduced morbidity and mortality from diarrheal and respiratory diseases. Recent findings suggest that exclusive breast-feeding may pose less risk of HIV-1 transmission than the more common practice of mixed feeding (i.e., breast-feeding concurreptwith the feeding of water, other fluids, and foods), which has important infant feeding policy implications for low-resource settings. This paper reviews the biologic mechanisms associated with exclusive breast-feeding that provide protection against gastrointestinal, respiratory, and atopic diseases, and evaluates the relevance of these mechanisms for HIV-1 transmission. Potential mechanisms include reduction in dietary antigens and enteric pathogens that may maintain integrity of the intestinal mucosal barrier and limit inflammatory responses of the gut mucosa; promotion of beneficial intestinal microflora that may increase resistance to infection and modulate the infant's immune response; alteration in specific antiviral or anti-inflammatory factors in human milk that may modulate maternal hormonal or immunologic status; and maintenance of mammary epithelial integrity that may reduce viral load in breast milk. [source] Probiotics and prebiotics in atopic dermatitis: review of the theoretical background and clinical evidencePEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 2p2 2010Leontien B. Van Der Aa van der Aa LB, Heymans HSA, van Aalderen WMC, Sprikkelman AB. Probiotics and prebiotics in atopic dermatitis: review of the theoretical background and clinical evidence. Pediatr Allergy Immunol 2010: 21: e355,e367. © 2009 John Wiley & Sons A/S The prevalence of atopic dermatitis (AD) has risen over the past decades, especially in western societies. According to the revised hygiene hypothesis this increase is caused by a changed intestinal colonization pattern during infancy, which has an impact on the immune system. Manipulating the intestinal microflora with pro-, pre- or synbiotics is an innovative way to prevent or treat AD. This review provides an overview of the theoretical basis for using probiotics and prebiotics in AD and presents the current evidence from randomized controlled trials (RCTs) regarding prevention and treatment of AD and food allergy in children with pro-, pre- and synbiotics. Seven RCTs on prevention and 12 RCTs on treatment were found by searching the Pubmed, Embase and Cochrane databases. Results of these trials are conflicting. In conclusion, at this moment there is not enough evidence to support the use of pro-, pre- or synbiotics for prevention or treatment of AD in children in clinical practice. [source] Health-beneficial effects of probiotics: Its mode of actionANIMAL SCIENCE JOURNAL, Issue 4 2009Yuji OHASHI ABSTRACT It is now widely recognized that probiotics have health-beneficial effects on humans and animals. Probiotics should survive in the intestinal tract to exert beneficial effects on the host's health. To keep a sufficient level of probiotic bacteria in the gastrointestinal tract, a shorter interval between doses may be required. Although adherence to the intestinal epithelial cell and mucus is not a universal property of probiotics, high ability to adhere to the intestinal surface might strongly interfere with infection of pathogenic bacteria and regulate the immune system. The administration of probiotic Lactobacillus stimulated indigenous Lactobacilli and the production of short-chain fatty acids. This alteration of the intestinal environment should contribute to maintain the host's health. The immunomodulatory effects of probiotics are related to important parts of their beneficial effects. Probiotics may modulate the intestinal immune response through the stimulation of certain cytokine and IgA secretion in intestinal mucosa. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain used. Differences in indigenous intestinal microflora significantly alter the magnitude of the effects of a probiotic. Specific probiotic strains suitable for each animal species and their life stage as well as each individual should be found. [source] Immune response, disease resistance and intestinal microflora of juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of pantothenic acidAQUACULTURE NUTRITION, Issue 4 2010Z.-P. WEN Abstract This study was to investigate the effect of dietary pantothenic acid (PA) on the disease resistance, immune response and intestinal microflora on juvenile Jian carp (Cyprinus carpio var. Jian). Seven diets (4.0, 15.5, 25.6, 36.1, 45.9, 56.1 and 65.9 mg PA kg,1) were fed to Jian carp (12.95 ± 0.03 g) for 9 weeks. After 9-week feeding trial, the challenge experiment with Aeromonas hydrophila was conducted to determine the impact of PA on fish disease resistance. Survival rate after challenge was promoted with the increasing PA levels (P < 0.05). Blood counts also significantly increased up to the dietary PA level of 25.6 mg PA kg,1 (P < 0.05). Leucocyte phagocytic activity, lectin potency, lysozyme and acid phosphatase activity, and total iron-binding capacity were improved with increasing PA levels (P < 0.05). Serum immunoglobulin M level and agglutination antibody titre to A. hydrophila were increased (P < 0.05) in fish fed the diets with the dietary PA levels between 56.1 and 65.9 mg kg,1. PA also promoted the growth and reproduction of Lactobacillus and depressed Escherichia coli and A. hydrophila (P < 0.05). These results suggested that pantothenic acid could improve disease resistance, immune response, and the balance of intestinal microflora in juvenile Jian carp. [source] Effects of dietary pyridoxine on disease resistance, immune responses and intestinal microflora in juvenile Jian carp (Cyprinus carpio var. Jian)AQUACULTURE NUTRITION, Issue 3 2010L. FENG Abstract This experiment was conducted to evaluate the effects of dietary pyridoxine on disease resistance, immune responses and intestinal microflora of fish. A total of 1050 Jian carp (11.71 ± 0.05 g) were randomly distributed into seven groups, feeding diets containing graded levels of pyridoxine (0.2, 1.7, 3.2, 5.0, 6.3, 8.6 and 12.4 mg kg,1 diet). After 80 days of feeding, a challenge trial was conducted by injection of Aeromonas hydrophila for 17 days. Results indicated that with increasing dietary pyridoxine concentration up to 5.0 mg kg,1 diet, survival rate after challenge with A.hydrophila and phagocytic activity of leukocyte were improved (P < 0.05), and plateaued thereafter (P > 0.05). Red blood cell and white blood cell counts were lowest when fed the diet containing 1.7 mg pyridoxine kg,1 diet. Haemagglutination titre, lysozyme activity, acid phosphatase activity, total iron-binding capacity, antibody titre and immunoglobulin M content followed the similar pattern to that observed with survival rate. Aeromonas hydrophila, Escherichia coli and Lactobacillus counts in intestine were not affected by dietary pyridoxine concentration (P > 0.05). These results suggested that pyridoxine could enhance immune response of fish. [source] Effect of methionine on intestinal enzymes activities, microflora and humoral immune of juvenile Jian carp (cyprinus carpio var. Jian)AQUACULTURE NUTRITION, Issue 5 2009L. TANG Abstract An 8-week feeding experiment was conducted to determine the effect of dietary methionine supplementation on intestinal microflora and humoral immune of juvenile Jian carp (initial weight of 9.9 ± 0.0 g) reared in indoor flow-through and aerated aquaria. Eight amino acid test diets (350 g kg,1 crude protein, CP), using fish meal, soybean-condensed protein and gelatin as intact protein sources supplemented with crystalline amino acids, were formulated to contain graded levels of methionine (0.6,22.0%) at a constant dietary cystine level of 3 g kg,1. Each diet was randomly assigned to three aquaria. Growth performance and feed utilization were significantly influenced by the dietary methionine levels (P < 0.05). Maximum weight gain, feed intake occurred at 12 g kg,1 dietary methionine (P < 0.05). Methionine supplementation improved hepatopancreas and intestine weight, hepatosomatic and intestine index, intestinal ,-glutamyltransferase and creatine kinase activity, Lactobacillus count, Bacillus count, lysozyme activities, lectin potency, sim-immunoglobulin M content, addiment C3,C4 contents and serum total iron-binding capacity and declined Escherichia coli and Aeromonas counts. Quadratic regression analysis of weight gain against dietary methionine levels indicated that the optimal dietary methionine requirement for maximum growth of juvenile Jian carp is 12 g kg,1 of the dry diet in the presence of 3 g kg,1 cystine. [source] Growth, digestive capacity and intestinal microflora of juvenile Jian carp (Cyprinus carpio var. Jian) fed graded levels of dietary inositolAQUACULTURE RESEARCH, Issue 8 2009Wei-Dan Jiang Abstract A 60-day feeding trial was carried out with juvenile Jian carp (Cyprinus carpio var. Jian) to study the effects of myo -inositol (MI) on the growth, digestive enzyme and intestinal microbial population. Diets with seven levels of inositol (163.5, 232.7, 384.2, 535.8, 687.3, 838.8 and 990.3 mg MI kg,1 diet) were fed to Jian carp (initial weight 22.28±0.07 g). Per cent weight gain (PWG) was improved with increasing inositol levels up to 535.8 mg MI kg,1 diet (P<0.05), and plateaued (P>0.05). The protein production value, lipid production value and ash production value were increased with increasing dietary inositol levels up to 384.2, 838.8 and 838.8 mg MI kg,1 diet respectively (P<0.05). Although intestinal protein content and trypsin activity were not affected by inositol levels (P>0.05), chymotrypsin, lipase and amylase activities in intestine were the lowest for fish fed the MI-unsupplemented diet (P<0.05). Alkaline phosphatase, Na+, K+ -ATPase, ,-glutamyl transpeptidase and creatinkinase activities in the intestine were increased with an increase in the inositol levels up to 384.2,687.3 mg MI kg,1 diet (P<0.05). Intestinal Aeromonas hydrophila and Escherichia coli decreased with an increase in the levels of dietary inositol up to 232.7 and 687.3 mg MI kg,1 diet respectively (P<0.05), while Lactobacillus in the intestine increased with an increase in inositol levels up to 990.3 mg MI kg,1 diet (P<0.05). In conclusion, inositol improved growth, digestive capacity and intestinal microbial population of juvenile Jian carp, and the dietary inositol requirement for PWG of juvenile Jian carp is 518.0 mg MI kg,1 diet. [source] Complexity of Anti-immunosenescence Strategies in HumansARTIFICIAL ORGANS, Issue 10 2006Miriam Capri Abstract:, Immunosenescence is characterized by three main aspects: (i) the shrinkage of the T cell repertoire and the accumulation of oligoclonal expansions (megaclones) of memory/effector cells directed toward ubiquitary infectious agents; (ii) the involution of the thymus and the exhaustion of naïve T cells; and (iii) a chronic inflammatory status called inflamm-aging. We present here possible strategies to counteract these main aspects of immunosenescence in humans with particular attention to the reduction of antigenic load by pathogens, such as CMV, and the normalization of intestinal microflora, the possible utilization of IL-7 to reverse thymic involution, the purging of megaclones, the forced expression of CD28 on T lymphocytes, the reduction of inflamm-aging and the administration of nutrients such as vitamin D. Possible drawbacks of all these strategies are discussed. Finally, the complexity of a rejuvenation approach is stressed, with particular attention to the inhibitory role played by the "old microenvironment" on the performance of progenitor cells, the best candidate to counteract the decline in regenerative potential characteristic of organs and tissues from old organisms. [source] Bacteroides thetaiotaomicron: a dynamic, niche-adapted human symbiontBIOESSAYS, Issue 10 2003Laurie E. Comstock The coevolution of humans with their intestinal microflora has resulted in cooperative relationships that have shaped the biology and the genomes of these symbiotic partners. Bacteroides thetaiotaomicron is one such bacterial symbiont that is a dominant member of the intestinal microbiota of humans and other mammals. The recent report of the genome sequence of B. thetaiotaomicron1 is the first reported for an abundant Gram-negative organism of the human colonic microbiota and, as such, provides the first glimpse on a genomic scale of the genetic arsenal used by a Gram-negative symbiont to dominate in this ecosystem. The genome has revealed large expansions of many paralogous groups of genes that encode products essential to the organism's ability to successfully compete in this environment. Most noteable is the organism's abundant machinery for utilizing a large variety of complex polysaccharides as a source of carbon and energy. The proteome also reveals the organism's extensive ability to adapt and regulate expression of its genes in response to the changing ecosystem. These factors, as well as others highlighted below, suggest an incredibly flexible and adaptable organism that is exquisitely equipped to dominate in its challenging and competitive niche. BioEssays 25:926,929, 2003. © 2003 Wiley Periodicals, Inc. [source] Novel physiological function of fructooligosaccharidesBIOFACTORS, Issue 1-4 2004Takahisa Tokunaga Abstract Two key properties of short chain fructooligosaccharides (sc-FOS) which lead to physiological functions are indigestibility in the small intestine and fermentability in the colon. Sc-FOS is converted into short chain fatty acids (SCFAs) by intestinal bacteria in the colon and absorbed. Through the metabolic pathway, sc-FOS improves gastrointestinal (GI) condition such as relief from constipation, formation of preferable intestinal microflora and intestinal immunomodulation those are known as prebiotics' function. Besides improvement of GI condition, dietary sc-FOS influences on calcium and magnesium absorption in the colon. A major mineral absorption site is the small intestine, but the colon also works as a Ca and Mg absorption site with an aid of SCFAs made from sc-FOS. Furthermore dietary sc-FOS influences on bioavailability of soy-isoflavones. Plasma and urinal concentration of Genistein and Daidzein, aglycones of Daidzin and Genistin, are higher in the rat fed with sc-FOS than the control rat. An additive effect of dietary isoflavone and sc-FOS was observed on the bone mineral density in OVX mice and moreover sc-FOS increased ceacal ,-glycosidase activity and equol production. These results suggest that FOS increase the bioavailability of isoflavones. [source] Simultaneous determination of the flavonoid aglycones diosmetin and hesperetin in human plasma and urine by a validated GC/MS method: in vivo metabolic reduction of diosmetin to hesperetinBIOMEDICAL CHROMATOGRAPHY, Issue 2 2009Marios Spanakis Abstract Diosmetin and hesperetin are the aglycones of the flavonoid glycosides diosmin and hesperidin which occur naturally in citrus fruit. A GC/MS method for the simultaneous determination of diosmetin and hesperetin in human plasma and urine has been developed and validated. The method was linear in the 2,300 ng/mL concentration range for both diosmetin and hesperetin in plasma and urine (r >0.999). The precision of the method was better than 6.01 and 7.16% for diosmetin and hesperetin, respectively, and the accuracy was 96.76,100.40% and 95.00,105.50% for diosmetin and hesperetin, respectively. The lower limit of quantitation was found to be 2 ng/mL for both analytes in plasma and urine. Recovery of diosmetin, hesperetin and internal standard naringenin was greater than 82.5%. The method has been applied for the determination of diosmetin and hesperetin in plasma and urine samples obtained from a healthy male subject following a single oral 1000 mg dose of the flavonoid glycoside diosmin. The presence of hesperetin in plasma and urine samples indicates the metabolic reduction of diosmetin to its flavanone analogue hesperetin through reduction of the 2,3 double bond of the C-ring by the enzymes of bacteria of the intestinal microflora. Copyright © 2008 John Wiley & Sons, Ltd. [source] Escherichia coli,-haemolysin induces focal leaks in colonic epithelium: a novel mechanism of bacterial translocationCELLULAR MICROBIOLOGY, Issue 10 2007Hanno Troeger Summary Extraintestinal pathogenic Escherichia coli (ExPEC) are usually harmless colonizer of the intestinal microflora. However, they are capable to translocate and cause life-threatening disease. Translocation of ExPEC isolates was quantified in colonic monolayers. Transepithelial resistance (Rt) was monitored and local changes in conductivity analysed with conductance scanning. Confocal microscopy visualized the translocation route. Corroboratory experiments were performed on native rat colon. One translocating strain E. coli O4 was identified. This translocation process was associated with an Rt decrease (36 ± 1% of initial resistance) beginning only 2 h after inoculation. The sites of translocation were small defects in epithelial integrity (focal leaks) exhibiting highly increased local ion permeability. Translocation was enhanced by preincubation of monolayers with tumour necrosis factor-, or interleukin-13. Mutant strains lacking alpha-haemolysin lost the ability to induce focal leaks, while this effect could be restored by re-introducing the haemolysin determinant. Filtrate of a laboratory strain carrying the alpha-haemolysin operon was sufficient for focal leak induction. In native rat colon, E. coli O4 decreased Rt and immunohistology demonstrated focal leaks resembling those in cell monolayers. E. coli,-haemolysin is able to induce focal leaks in colonic cell cultures as well as in native colon. This process represents a novel route of bacterial translocation facilitated by pro-inflammatory cytokines. [source] Allergic rhinitis in children: environmental factorsCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2004Y. Okamoto Summary Increasing numbers of patients with allergic rhinitis are being noted on a global scale. Over 90% of Japanese patients with perennial allergic rhinitis show allergic reaction to the mite antigen and major pollen allergens such as Japanese cedar and Japanese cypress, which are carried long distances (> 100 km) by wind and hence can produce substantial harmful effects even in metropolitan areas. This situation is distinct from that in the West, where the most common anemophilous allergen, ragweed, travels much shorter distances of up to only several hundred metres. Environmental factors such as increased antigen, air pollution, diet, intestinal microflora, decreased incidence of infections, smoking, breastfeeding and vaccination may play important roles in the development and manifestation of allergic rhinitis in genetically predisposed subjects. In particular, in newborn infants, who carry the Th2 predominant state, environmental factors may greatly affect the development of balanced production of Th1 and Th2 cytokines. However, the contribution of any environmental factor to the postnatal development of allergic rhinitis has not been sufficiently determined. A better understanding of the processes involved may lead directly to better treatment or cure of allergic rhinitis. [source] Reproducing the bifidogenic effect of human milk in formula-fed infants: Why and how?ACTA PAEDIATRICA, Issue 2005Guido E Moro Abstract Awareness of the key role of the intestinal microflora in the generation of the immunophysiological regulation and in the defence against pathogenic agents has attracted our interest in ways of manipulating the microbiota to improve health. Dietary modulation of the intestinal microflora is today one of the main topics of interest in the nutritional sciences. Performing this modulation in the neonatal or early infancy period, when immunological programming takes place, is a relatively new concept. Fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) are prebiotics whose bifidogenic activity has been proven in adults. However, only recently have they been combined in infant formulas to reproduce the prebiotic effect of human milk oligosaccharides. In two consecutive trials, it has been demonstrated that supplementation of infant formulas with a mixture of GOS and FOS modified the fecal flora of term and preterm infants, stimulating the growth of Bifidobacteria. In the trial with term infants, the bifidogenic effect of the prebiotic mixture was dose dependent and there was also a significant increase in the number of Lactobacilli in the supplemented group. These findings offer a promising horizon for the early prevention of allergy and infections in infants. [source] Increased conjugation frequencies in clinical Enterococcus faecium strains harbouring the enterococcal surface protein gene espCLINICAL MICROBIOLOGY AND INFECTION, Issue 6 2006B. Lund Abstract This study compared the in-vitro ability of Enterococcus faecium isolates of different origin to acquire vanA by conjugation in relation to the occurrence of the esp gene. In total, 29 clinical isolates (15/29 esp+), 30 normal intestinal microflora isolates (2/30 esp+) and one probiotic strain (esp -) were studied with a filter-mating assay. Conjugation events were confirmed by PCR and pulsed-field gel electrophoresis. Among the infection-derived isolates, the esp+ isolates had higher conjugation frequencies compared with esp - isolates (p < 0.001), with a median value of 6.4 × 10,6 transconjugants/donor. The probiotic strain was shown to acquire vanA vancomycin resistance in in-vitro filter mating experiments. [source] | |||||||||||||||||||