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Lactobacillus
Kinds of Lactobacillus Terms modified by Lactobacillus Selected Abstractsd -Alanyl ester depletion of teichoic acids in Lactobacillus reuteri 100-23 results in impaired colonization of the mouse gastrointestinal tractENVIRONMENTAL MICROBIOLOGY, Issue 7 2007Jens Walter Summary The dlt operon of Gram-positive bacteria encodes proteins required for the incorporation of d -alanine esters into cell wall-associated teichoic acids (TA). d -Alanylation of TA has been shown to be important for acid tolerance, resistance to antimicrobial peptides, adhesion, biofilm formation, and virulence of a variety of pathogenic organisms. The aim of this study was to determine the importance of d -alanylation for colonization of the gastrointestinal tract by Lactobacillus reuteri 100-23. Insertional inactivation of the dltA gene resulted in complete depletion of d -alanine substitution of lipoteichoic acids. The dlt mutant had similar growth characteristics as the wild type under standard in vitro conditions, but formed lower population sizes in the gastrointestinal tract of ex- Lactobacillus -free mice, and was almost eliminated from the habitat in competition experiments with the parental strain. In contrast to the wild type, the dlt mutant was unable to form a biofilm on the forestomach epithelium during gut colonization. Transmission electron microscope observations showed evidence of cell wall damage of mutant bacteria present in the forestomach. The dlt mutant had impaired growth under acidic culture conditions and increased susceptibility to the cationic peptide nisin relative to the wild type. Ex vivo adherence of the dlt mutant to the forestomach epithelium was not impaired. This study showed that d -alanylation is an important cell function of L. reuteri that seems to protect this commensal organism against the hostile conditions prevailing in the murine forestomach. [source] Probiotics: do they have a role in oral medicine and dentistry?EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 3 2005Jukka H. Meurman This review describes current knowledge on probiotic bacteriotherapy from the oral health perspective. Recent experimental studies and results from randomized controlled trials have shown that certain gut bacteria, in particular species of Lactobacillus and Bifidobacterium, may exert beneficial effects in the oral cavity by inhibiting cariogenic streptococci and Candida sp. Probiotics have been successfully used to control gastro-intestinal diseases. They also appear to alleviate symptoms of allergy and diseases with immunological pathology. The mechanisms of probiotic action appear to link with colonization resistance and immune modulation. Lactic acid bacteria can produce different antimicrobial components such as organic acids, hydrogen peroxide, carbon peroxide, diacetyl, low molecular weight antimicrobial substances, bacteriocins, and adhesion inhibitors, which also affect oral microflora. However, data is still sparse on the probiotic action in the oral cavity. More information is needed on the colonization of probiotics in the mouth and their possible effect on and within oral biofilms. There is every reason to believe that the putative probiotic mechanisms of action are the same in the mouth as they are in other parts of the gastrointestinal tract. Because of the increasing global problem with antimicrobial drug resistance, the concept of probiotic therapy is interesting and pertinent, and merits further research in the fields of oral medicine and dentistry. [source] Adherence factors of Lactobacillus in the human gastrointestinal tractFEMS MICROBIOLOGY LETTERS, Issue 2 2007Mónica Perea Vélez Abstract Despite the increasing number of scientific reports describing adhesion of Lactobacillus to components of the human intestinal mucosa, information on the surface molecules mediating this adhesion and their corresponding receptors is fragmentary. This MiniReview compiles present knowledge of the genetically and functionally characterized Lactobacillus factors responsible for mediating adhesion to different components of the human gastrointestinal tract. In addition, for the proteins among these factors, the domain structure is discussed, and where appropriate the results of in silico analyses are reported. [source] Identification of the ornithine decarboxylase gene in the putrescine-producer Oenococcus oeni BIFI-83FEMS MICROBIOLOGY LETTERS, Issue 2 2004Angela Marcobal Abstract We report here the identification of an ornithine decarboxylase (ODC) gene in the putrescine-producer Oenococcus oeni BIFI-83 strain. The gene contains a 2,235-nucleotide open reading frame encoding a 745-amino acid residues protein with a deduced molecular mass of 81 kDa. The primary structure of the ODC deduced from the nucleotide sequence has a consensus sequence containing the pyridoxal-5-phosphate (PLP) binding domain, and the critical amino acids residues involved in enzymatic activity are also conserved. As determined by BLAST analysis, the deduced amino acid sequence of the odc gene shares a 67% identity with the ODC protein from Lactobacillus 30a. The odc gene appears to be rarely present in the genome of O. oeni, since in a screening for the presence of this gene in 42 oenococcal strains none of the strains possessed an odc gene copy. [source] Flavour formation by lactic acid bacteria and biochemical flavour profiling of cheese productsFEMS MICROBIOLOGY REVIEWS, Issue 3 2005Gerrit Smit Abstract Flavour development in dairy fermentations, most notably cheeses, results from a series of (bio)chemical processes in which the starter cultures provide the enzymes. Particularly the enzymatic degradation of proteins (caseins) leads to the formation of key-flavour components, which contribute to the sensory perception of dairy products. More specifically, caseins are degraded into peptides and amino acids and the latter are major precursors for volatile aroma compounds. In particular, the conversion of methionine, the aromatic and the branched-chain amino acids are crucial. A lot of research has focused on the degradation of caseins into peptides and free amino acids, and more recently, enzymes involved in the conversion of amino acids were identified. Most data are generated on Lactococcus lactis, which is the predominant organism in starter cultures used for cheese-making, but also Lactobacillus, Streptococcus, Propionibacterium and species used for surface ripening of cheeses are characterised in their flavour-forming capacity. In this paper, various enzymes and pathways involved in flavour formation will be highlighted and the impact of these findings for the development of industrial starter cultures will be discussed. [source] Investigation of the Immunomodulatory Effects of Lactobacillus casei and Bifidobacterium lactis on Helicobacter pylori InfectionHELICOBACTER, Issue 3 2008Li Zhang Abstract Background:,Lactobacillus and Bifidobacterium species have shown beneficial effects in the treatment of Helicobacter pylori infection; however, the mechanisms behind such effects are not fully understood. In this study, we have investigated the immunomodulatory effects of probiotics in a mouse model of H. pylori infection. Materials and methods:,H. pylori -infected C57BL/6 mice were treated with L. casei L26, B. lactis B94, or no probiotics for 5 weeks, respectively. Mice not infected with H. pylori were included as normal controls. Gastric histology, protein levels of interleukin (IL)-1,, IL-10, IL-12/23p40, and H. pylori colonization density in the gastric tissues, as well as H. pylori -specific antibodies were examined. Results:, In mice receiving L. casei L26 and B. lactis B94, gastric neutrophil infiltration and IL-1, were significantly decreased and IL-10 was significantly increased as compared with mice receiving no probiotics. In mice receiving B. lactis B94, IL-12/23p40 was significantly increased and H. pylori IgG was significantly reduced as compared with mice receiving no probiotics. No significant difference of H. pylori colonization was observed among the three groups of mice. Conclusion:, The reduced level of IL-1, and neutrophil infiltration observed in mice infected with H. pylori following treatment with L. casei L26 and B. lactis B94 resulted from a modulation of immune response rather than a decrease of H. pylori colonization. Furthermore, B. lactis B94 has the intrinsic ability to promote a Th1 immune response through an increase in IL-12/IL-23. [source] Technological characterization of the natural lactic acid bacteria of artisanal Turkish White Pickled cheeseINTERNATIONAL JOURNAL OF DAIRY TECHNOLOGY, Issue 2 2008ELIF DAGDEMIR The aim of this study was to characterize the lactic acid bacteria (LAB) isolated from White Pickled cheeses produced with traditional methods; and to improve the quality of cheesemaking with a selection of bacterial cultures from artisanal White cheeses. LAB were isolated and identified from 30 White Pickled cheese samples collected from various cities in Turkey. Also, the numbers of several microbial groups (total aerobic mesophilic bacteria, LAB, enterococci, coliforms, moulds and yeasts) of cheese samples were enumerated. Lactobacilli, lactococci and enterococci were the most abundant microbial groups. The numbers of Enterococcus and Lactobacillus isolates were higher than those of the other LAB. Enterococcus faecalis (24.43%), Enterococcus faecium (17.61%) and Lactobacillus fermentum (19.88%) isolates were the most frequently isolated species. Lactococcus strains showed the highest acidifying activity, followed by Enterococcus and Lactobacillus strains. Proteolytic activity of Enterococcus faecalis strains was higher than that of the other enterococci species, except Enterococcus avium strains. Within lactobacilli strains, the highest mean proteolytic activity was that of Lactobacillus bifermentans, Lactobacillus brevis and Lactobacillus casei strains. [source] Chemical and microbiological quality of Garris, Sudanese fermented camel's milk productINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 3 2006Abdel Moneim El-Hadi Sulieman Summary In the present study, some of the chemical and microbiological characteristics of garris, a Sudanese traditionally fermented camel's milk product, were investigated. The chemical analyses included, pH, titrable acidity and ethanol contents. A total of 100 strains of lactic acid bacteria (LAB) were isolated from twenty samples of traditionally fermented household garris. The selected isolates were phenotypically characterized by their ability to ferment 49 carbohydrates using API 50 CHL kits and additional biochemical tests. LAB dominated the microflora of garris samples, and the major genera were Lactobacillus (74%), followed by Lactococcus (12%), Enterococcus (10%) and Leuconostocs (4%). The most predominant Lactobacillus species were identified as Lactobacillus paracasei ssp. paracasei (64 strains), L. fermentum (seven strains) and only three strains as L. plantarum. Most strains produced the enzymes that are relevant to cultured dairy product processing. The Lactococcus species were identified as Lactococcus lactis. The average pH value of the samples was 4.42 ± 0.21. The pH values were accompanied with increasing of titrable acidity which averaged 1.72 ± 0.04%. The relatively high amounts of ethanol detected in all samples (average 1.40 ± 0.03%) together with the high yeasts counts (6.0 ± 0.53 log10 cfu mL,1), indicated that the fermentation process of garris is a yeast-lactic fermentation. [source] Antimicrobial activity of essential oils and structurally related synthetic food additives towards Clostridium perfringensJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2009W. Si Abstract Aims:, To assess the potential of essential oils and structurally related synthetic food additives in inhibiting the growth of Clostridium perfringens for the control of necrotic enteritis in chickens. Methods and Results:, The antimicrobial activity of essential oils/compounds was measured by determining the inhibition of bacterial growth. Thirty-three of 66 oils/compounds exhibited ,80% inhibition. Seven with the highest potency were further studied. The oils/compounds had MIC95 values between 167 and 425 ,g ml,1. Most of them were tolerant to low pH (2·0) and exhibited minor or no inhibition of Lactobacillus isolates from the chicken intestine. When mixed with chicken ileal digesta, the oils/compounds retained their efficacy against C. perfringens, but had little effect on the total number of lactobacilli and anaerobic bacteria in the digesta. Conclusions:, Some essential oils/compounds demonstrated good potential in controlling C. perfringens. Significance and Impact of the Study:, This study has identified candidates of essential oils/compounds for in vivo studies for the control of necrotic enteritis in chickens. [source] Oligonucleotide microarrays for the detection and identification of viable beer spoilage bacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2008D.G. Weber Abstract Aims:, The design and evaluation of an oligonucleotide microarray in order to detect and identify viable bacterial species that play a significant role in beer spoilage. These belong to the species of the genera Lactobacillus, Megasphaera, Pediococcus and Pectinatus. Methods and Results:, Oligonucleotide probes specific to beer spoilage bacteria were designed. In order to detect viable bacteria, the probes were designed to target the intergenic spacer regions (ISR) between 16S and 23S rRNA. Prior to hybridization the ISR were amplified by combining reverse transcriptase and polymerase chain reactions using a designed consenus primer. The developed oligonucleotide microarrays allows the detection of viable beer spoilage bacteria. Conclusions:, This method allows the detection and discrimination of single bacterial species in a sample containing complex microbial community. Furthermore, microarrays using oligonucleotide probes targeting the ISR allow the distinction between viable bacteria with the potential to grow and non growing bacteria. Significance and Impact of the Study:, The results demonstrate the feasibility of oligonucleotide microarrays as a contamination control in food industry for the detection and identification of spoilage micro-organisms within a mixed population. [source] The bacterial flora of vacuum-packed cold-smoked salmon stored at 7°C, identified by direct 16S rRNA gene analysis and pure culture techniqueJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007T.C. Olofsson Abstract Aims:, The indigenous flora of freshly chilled cold-smoked salmon just after the vacuum packaging, and the spoilage flora after storage, in vacuum package at 7°C for 19 days, were to be investigated with two different sampling strategies. Methods and Results:, Identification was performed using 16S rRNA sequencing of both isolated bacteria and bacterial DNA from tissue extract. The indigenous flora of fresh cold-smoked vacuum-packed salmon was dominated by, in order, Brochothrix thermosphacta, Yersinia ruckeri, Photobacterium and Carnobacterium, whereas the spoilage flora of the same product stored at 7°C for 19 days was dominated by Lactobacillus and Photobacterium. The two sampling strategies showed similar results on the fish flora. Several new types of Photobacterium sequences, closely related to Photobacterium iliopiscarium and Photobacterium phosphoreum, were found from both the freshly processed and the stored salmon, indicating that smoked salmon harbours at least three different, as yet unknown, Photobacterium species. Conclusions:, Ten per cent of the bacterial flora multiplying on chilled, vacuum-packed, cold-smoked salmon comprised unknown species. The two sampling strategies complement each other. Significance and Impact of the Study:, As cold-smoked salmon is consumed without heat-treatment, the presence of undefined bacteria in high numbers should be considered in public health assessments. [source] Identification and production of a bacteriocin from Enterococcus mundtii QU 2 isolated from soybeanJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2005T. Zendo Abstract Aims:, Identification of the bacteriocin produced by Enterococcus mundtii QU 2 newly isolated from soybean and fermentative production of the bacteriocin. Methods and Results:, The bacteriocin produced by Ent. mundtii QU 2 inhibited the growth of various indicator strains, including Enterococcus, Lactobacillus, Leuconostoc, Pediococcus and Listeria. The bacteriocin activity was stable at wide pH range and against heat treatment, but completely abolished by proteolytic enzymes. The bacteriocin was purified from the culture supernatant by the three-step chromatographic procedure. Mass spectrometry, amino acid sequencing and DNA sequencing revealed that the bacteriocin was similar to class IIa bacteriocins produced by other Ent. mundtii strains. The bacteriocin production decreased in the absence of glucose, nitrogen sources, or Tween 80 in MRS medium. Additionally, it was strongly suppressed by addition of Ca2+ (CaCO3 or CaCl2). In pH-controlled fermentations, the highest bacteriocin production was achieved at pH 6·0, whereas the highest cell growth was obtained at pH 7·0. Conclusions:,Ent. mundtii QU 2 produced a class IIa bacteriocin. Some growth factors (e.g. Ca2+ and pH) influenced the bacteriocin production. Significance and Impact of the Study:, A new soybean isolate, Ent. mundtii QU 2 was found to be a class IIa bacteriocin producer. Factors influencing the bacteriocin production described herein are valuable for applications of the bacteriocins from Ent. mundtii strains. [source] Stationary-phase acid and heat treatments for improvement of the viability of probiotic lactobacilli and bifidobacteriaJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2004M. Saarela Abstract Aims:, To investigate whether sublethal treatments of stationary-phase probiotic cultures enhance their survival during lethal treatments and to adapt these treatments to the fermenter-scale production of probiotic cultures. Methods and Results:, Conditions for acid and heat pretreatments were screened for three Lactobacillus and two Bifidobacterium strains. Strains were sublethally treated both at laboratory scale and at fermenter scale in a strain-specific manner and exposed to a subsequent lethal treatment. At laboratory scale viability improvement was detected in each strain. However, improvement was more pronounced in the Lactobacillus than in the Bifidobacterium strains. At fermenter scale three strains were tested: for the two Lactobacillus strains a marked improvement in viability was obtained whereas for the Bifidobacterium strain the improvement was either minor or not detected. Conclusions:, Development of treatments for viability enhancement of probiotic strains is feasible, but strain-specific optimization is necessary to obtain notable improvements. Significance and Impact of the Study:, Strain-specific treatments were developed for the viability enhancement of stationary-phase probiotic cells both at laboratory and fermenter scale. These results can be utilised in the production of probiotic cultures with improved viability. [source] Conjugated linoleic acid biosynthesis by human-derived Bifidobacterium speciesJOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2003M. Coakley Abstract Aims: To assess strains of Lactobacillus, Lactococcus, Pediococcus and Bifidobacterium for their ability to produce the health-promoting fatty acid conjugated linoleic acid (CLA) from free linoleic acid. Methods and Results: In this study, strains of Lactobacillus, Lactococcus, Pediococcus and Bifidobacterium were grown in medium containing free linoleic acid. Growth of the bacteria in linoleic acid and conversion of the linoleic acid to CLA was assessed. Of the bacteria assessed, nine strains of Bifidobacterium produced the c9, t11 CLA isomer from free linoleic acid. The t9, t11 CLA isomer was also produced by some strains, but at much lower concentrations. Conclusions: The production of CLA by bifidobacteria exhibited considerable interspecies variation. Bifidobacterium breve and B. dentium were the most efficient CLA producers among the range of strains tested, with B. breve converting up to 65% linoleic acid to c9, t11 CLA when grown in 0·55 mg ml,1 linoleic acid. Strains also varied considerably with respect to their sensitivity to linoleic acid. Significance and Impact of the Study: The production of CLA by probiotic bifidobacteria offers a possible mechanism for some health-enhancing properties of bifidobacteria and provides novel opportunities for the development of functional foods. [source] Comparative study of nine Lactobacillus fermentum bacteriophagesJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2001R. Foschino Aims:,To investigate the basic properties of six temperate and three virulent phages, active on Lactobacillus fermentum, on the basis of morphology, host ranges, protein composition and genome characterization. Methods and Results:,All phages belonged to the Siphoviridae family; two of them showed prolate heads. The host ranges of seven phages contained a common group of strains. SDS-PAGE protein profiles, restriction analysis of DNA and Southern blot hybridization revealed a high degree of homology between four temperate phages; partial homologies were also detected among virulent and temperate phages. Clustering derived from host range analysis was not related to the results of the DNA hybridizations. Conclusions:,The phages investigated have common characteristics with other known phages active on the genus Lactobacillus. Sensitivity to viral infection is apparently enhanced by the presence of a resident prophage. Significance and Impact of the Study:,These relationships contribute to the explanation for the origin of phage infection in food processes where Lact. fermentum is involved, such as sourdough fermentation. [source] Changes in the Lactobacillus community during Ricotta forte cheese natural fermentationJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2000F. Baruzzi The loss of microbial biodiversity due to the increase in large-scale industrial processes led to the study of the natural microflora present in a typical little known dairy product. The community of lactobacilli was studied in order to understand the natural fermentation of Ricotta forte cheese. The combined use of RAPD analysis, 16S rDNA sequencing and physiological tests allowed 33 different strains belonging to 10 species of Lactobacillus to be characterized. RAPD analysis revealed the heterogeneity of both the Lact. kefiri and Lact. paracasei species. The sequence analysis of the large 16S/23S rRNA spacer region enabled Lact. plantarum to be distinguished from Lact. paraplantarum, two closely related species belonging to the Lact. plantarum group. The recovery of strains endowed with interesting physiological characteristics, such as strong stress resistance, could improve technological and/or organoleptic characteristics of Ricotta forte cheese and other fermented foods. [source] A colony immunoblotting method for quantitative detection of a Bifidobacterium animalis probiotic strain in human faecesJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2000H. Duez A colony immunoblotting method has been developed to allow detection of the probiotic Bifidobacterium animalis strain DN-173 010 in human faecal samples. Rabbits were immunized with heat-killed DN-173 010 bacteria resulting in the production of an antiserum highly specific for bacteria belonging to Bif. animalis species. Of the 89 strains representative of 29 different bifidobacterial species tested, only the 15 strains of the Bif. animalis species could be detected with the antiserum. In Western immunoblotting the serum reacts with a protein of 45-kDa apparent molecular weight. None of the bacteria classically encountered in human faecal samples and able to grow on non-selective Columbia blood agar (enterobacteria, Bacteroides or Lactobacillus for instance) reacted with the antiserum. Taking advantage of the high specificity of the antiserum and of the absence of Bif. animalis bacteria in faeces samples of five human volunteers, we demonstrated that strain DN-173 010 survives the intestinal transit. Being based on a combination of semiselective cultivation and colony immunoblotting techniques, the method allowed detection of the Bif. animalis strain even when it represented only one thousandth of the total bifidobacterial population. [source] What is the evidence for the use of probiotics in the treatment of inflammatory bowel disease?JOURNAL OF CLINICAL NURSING, Issue 7-8 2010Virginia A Cary Aims and objectives., The purpose of this article is to investigate the use of probiotics in the treatment of inflammatory bowel disease. Background., Probiotics have been successfully used to treat various acute illnesses such as Clostridium difficile infection, rotovirus diarrhoea and traveller's diarrhoea. Recently, some studies have reported success with probiotics in the treatment of chronic intestinal diseases such as inflammatory bowel disease. Design., Literature review. Methods., A literature search was performed to include studies on Bifidobacteria -fermented milk, Escherichia coli, Lactobacillus, Saccharomyces boulardii, VSL #3 and probiotic use. Results of the literature are analysed, and a discussion is made regarding evaluation of the literature and implications for care. Results., The majority of probiotics studied have proven to have beneficial effects in the treatment of inflammatory bowel disease, especially when taken as a dietary adjunctive to standard treatment. All probiotics studied, with the exception of Lactobacillus GG and LA1, demonstrated positive results. Conclusions., The increasing use of probiotics combined with the insufficient knowledge regarding the use of probiotics in treating inflammatory bowel disease requires that future multilevel, multicentre large randomised control trials be conducted to understand better the specific measures and effectiveness of such treatment. Relevance to clinical practice., Given that few clinical trials exist to study the potential role of probiotics in the treatment of inflammatory bowel disease, it is imperative that healthcare providers become knowledgeable about the use of probiotics and their effects on inflammatory bowel disease. [source] VIRULENCE RESPONSE OF A SALMONELLA TYPHIMURIUM HILA:LACZY FUSION STRAIN TO SPENT MEDIA FROM PURE CULTURES OF SELECTED BACTERIA AND POULTRY CECAL MIXED CULTUREJOURNAL OF FOOD SAFETY, Issue 3 2002J.D. NUTT ABSTRACT Virulence gene expression in Salmonella is triggered by a variety of environmental factors including changes in the gastrointestinal environment of birds during different dietary regimes. The objective of this study was to determine if growth of specific microorganisms alters the environmental conditions sufficiently to signal Salmonella Typhimurium virulence response. Spent media was obtained from a Salmonella Typhimurium hilA:lacZY fusion strain, a poultry Salmonella Typhimurium strain, Eschcrichia coli K12, and Lactobacillus caseii Spent media samples were collected after 2, 4, 8 and 24 h of growth in brain heart infusion broth (BHI) and M9 media, ,-galactosidase assays were performed on the samples to determine virulence expression. Virulence response to Salmonella, spent media was 2-fold greater than Lactobacillus spent media at 4, 8 and 24 h growth (P < 0.05). Virulence expression almost doubled when exposed to Salmonella Typhimurium (NONA) spent media compared to mixed culture spent media at 4 h, and Salmonella Typhimurium (NONA) was significantly higher than mixed culture spent media at 24 h (P < 0.05). Based on these results, it appears that growth of similar bacterial species may alter the composition of rich media sufficiently to influence virulence. [source] Effect of Lactulose on Biotransformation of Isoflavone Glycosides to Aglycones in Soymilk by LactobacilliJOURNAL OF FOOD SCIENCE, Issue 3 2008T.T. Pham ABSTRACT:,Lactobacillus acidophilus 4461, L. acidophilus 4962, L. casei 290, and L. casei 2607 were used to hydrolyze isoflavone glycosides (IG) to biologically active forms,isoflavone aglycones (IA),in soymilk (SM) prepared from soy protein isolate (SPI) and soymilk supplemented with 0.5% (w/v) of lactulose (SML). L. acidophilus 4461 utilized the highest level of lactulose (3.01 mg/mL) and L. acidophilus 4962 utilized the least (0.86 mg/mL) at 24 h of incubation. The pH values decreased to 4.00 to 5.00 in SML, while they remained relatively high (6.15 to 6.36) in SM. Supplementation with lactulose significantly (P < 0.05) enhanced the viable counts of all the 4 Lactobacillus strains. At the end of incubation, the viable counts of Lactobacillus ranged from 8.08 to 8.25 log CFU/mL in SML compared to 6.99 to 7.11 log CFU/mL in SM. Supplementation with lactulose increased the biotransformation of IG to IA after 6 h of incubation. The presence of lactulose in the medium enhanced the biotransformation level of IG to IA by Lactobacillus up to 21.9%. The hydrolysis level of malonyl genistin and acetyl genistin in SML was much higher than in SM by all the 4 probiotic organisms. The biotransformation of IG to IA occurred rapidly during the 1st 12 h of incubation in both SML and SM. Among the 4 Lactobacillus strains, L. acidophilus 4461 biotransformed the highest level (88.8%) of IG to IA in SML compared to 68.2% in SM after 24 h of incubation. [source] Isolation and Characterization of Lactobacillus Species Having Potential for Use as Probiotic Cultures for DogsJOURNAL OF FOOD SCIENCE, Issue 3 2007S. 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] 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] Food and feed components for gut health-promoting adhesion of E. coli and Salmonella entericaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2008Petra M Becker Abstract BACKGROUND: A host runs less risk of contracting a gastrointestinal infection when enteropathogenic bacteria adhere to dietary fibers instead of to epithelial cell receptors. The aim of this study was to test the binding capacity of food and feed components for intestinal bacteria from various hosts using a miniaturized in vitro assay. In total, 18 dietary components were tested with four strains of E. coli, seven strains of Salmonella enterica and two strains of Lactobacillus. RESULTS: A comparison of the results obtained for all Salmonella strains tested revealed that konjac gum and sesame seed extract represented the most efficient binding matrices. Similarly, for all E. coli strains tested, sesame seed extract and artichoke performed well as binding matrices. Salmonella isolates from chickens adhered best to sesame seed extract. E. coli K88 and S. enterica sv. Typhimurium isolated from pigs effectively bound to BioMos®, pumpkin, sesame seed extract, and tomato. Sesame seed extract and tomato also had adhesive capacities for E. coli K 99, S. enterica sv. Dublin, and S. enterica sv. Typhimurium from calves. With human isolates, konjac gum showed a high binding potential for S. enterica and E. coli. CONCLUSION: The adhesion screening of different food and feed components resulted in highly discriminating product rankings. Copyright © 2008 Society of Chemical Industry [source] Antioxidative capacity produced by Bifidobacterium - and Lactobacillus acidophilus -mediated fermentations of konjac glucomannan and glucomannan oligosaccharidesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 7 2008Cheng-Hsin Wang Abstract BACKGROUND: Konjac glucomannan (KGM) has been shown to stimulate the growth of bifidobacteria and lactobacilli in the human and rat colon. This study investigated the antioxidative effects produced after 48 h in vitro fermentation of unhydrolysed KGM and two hydrolysed KGM fractions (KH1 and KH2 with degree of polymerisation 10 and 5 respectively) by Bifidobacterium adolescentis, B. bifidum, B. breve, B. longum and Lactobacillus acidophilus respectively. The inhibitory effect on conjugated diene formation, ferric-chelating capacity, ,,,-diphenyl-,-picrylhydrazyl (DPPH) radical-scavenging ability and thiobarbituric acid-reactive substances (TBARS) concentration produced by these fermentations were compared with those of oligofructose (OF) fermentation. RESULTS: The fermentation of KGM by each bacterial strain produced higher ferric-chelating capacity of the culture supernatant compared with KH2 or OF fermentation. In contrast, the fermentation of KGM by each bacterial strain led to lower inhibition of conjugated diene formation and lower radical-scavenging ability compared with KH2 fermentation. The fermentation of KH2 produced the lowest amount of TBARS. CONCLUSION: The fermentation of unhydrolysed KGM by colonic lactic acid bacteria in vitro produced antioxidative capacity mainly by preventing the initiation of ferrous ion-induced peroxidation, whereas the fermentation of konjac oligosaccahrides did so by increasing the radical-scavenging ability and eliminating lipid peroxide formation. Copyright © 2008 Society of Chemical Industry [source] Clinical trial: the effects of a fermented milk containing three probiotic bacteria in patients with irritable bowel syndrome , a randomized, double-blind, controlled studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2010M. SIMRÉN Summary Background, The effects of probiotic bacteria in IBS remain controversial. Aim, To study the effects of a probiotic product on IBS symptoms. Methods, We randomized 74 IBS patients to receive 8 weeks of daily treatment with 400 mL milk fermented with the yoghurt bacteria and containing Lactobacillus paracasei, ssp. paracasei F19, Lactobacillus acidophilus La5 and Bifidobacterium lactis Bb12 (Cultura; active) or acidified milk without these bacteria (control). The primary endpoint was the proportion of subjects reporting adequate relief of their IBS symptoms at least 50% of the weeks. IBS symptom severity, psychological symptoms and quality of life were assessed. Results, The proportion of responders was 38% (14/37 patients) in the active group and 27% (10/37 patients) in the control group (P = 0.3). IBS symptom severity improved significantly in both groups during the treatment period. This change was greater in the active group during the first 2 weeks, but thereafter, no significant group differences were seen. Conclusions, We could not detect a clearly positive effect of fermented milk containing three probiotic bacteria on GI symptoms in IBS patients compared with the control treatment. However, a trend towards a more favourable effect during the first weeks was seen in the active group. Aliment Pharmacol Ther,31, 218,227 [source] Clinical trial: a multistrain probiotic preparation significantly reduces symptoms of irritable bowel syndrome in a double-blind placebo-controlled studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2009E. A. WILLIAMS Summary Background, The efficacy of probiotics in alleviating the symptoms of irritable bowel syndrome (IBS) appears to be both strain- and dose-related. Aim, To investigate the effect of LAB4, a multistrain probiotic preparation on symptoms of IBS. This probiotic preparation has not previously been assessed in IBS. Methods, Fifty-two participants with IBS, as defined by the Rome II criteria, participated in this double blind, randomized, placebo-controlled study. Participants were randomized to receive either a probiotic preparation comprising two strains of Lactobacillus acidophilus CUL60 (NCIMB 30157) and CUL21 (NCIMB 30156), Bifidobacterium lactis CUL34 (NCIMB 30172) and Bifidobacterium bifidum CUL20 (NCIMB 30153) at a total of 2.5 × 1010 cfu/capsule or a placebo for 8 weeks. Participants reported their IBS symptoms using a questionnaire fortnightly during the intervention and at 2 weeks post-intervention. Results, A significantly greater improvement in the Symptom Severity Score of IBS and in scores for quality of life, days with pain and satisfaction with bowel habit was observed over the 8-week intervention period in the volunteers receiving the probiotic preparation than in the placebo group. Conclusion, LAB4 multistrain probiotic supplement may benefit subjects with IBS. [source] Clinical trial: effectiveness of Lactobacillus rhamnosus (strains E/N, Oxy and Pen) in the prevention of antibiotic-associated diarrhoea in childrenALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2008M. RUSZCZY Summary Background, Convincing evidence that probiotic administration can lower the risk of antibiotic-associated diarrhoea is limited to certain micro-organisms. Aim, To determine the efficacy of administration of Lactobacillus rhamnosus (strains E/N, Oxy and Pen) for the prevention of antibiotic-associated diarrhoea in children. Methods, Children (aged 3 months to 14 years) with common infections were enrolled in a double-blind, randomized, placebo-controlled trial in which they received standard antibiotic treatment plus 2 × 1010 colony forming units of a probiotic (n = 120) or a placebo (n = 120), administered orally twice daily throughout antibiotic treatment. Analyses were by intention to treat. Results, Any diarrhoea (,3 loose or watery stools/day for ,48 h occurring during or up to 2 weeks after the antibiotic therapy) occurred in nine (7.5%) patients in the probiotic group and in 20 (17%) patients in the placebo group (relative risk, RR 0.45, 95% confidence interval, CI 0.2,0.9). Three (2.5%) children in the probiotic group developed AAD (diarrhoea caused by Clostridium difficile or otherwise unexplained diarrhoea) compared to nine (7.5%) in the placebo group (RR 0.33, 95% CI 0.1,1.06). No adverse events were observed. Conclusion, Administration of L. rhamnosus (strains E/N, Oxy and Pen) to children receiving antibiotics reduced the risk of any diarrhoea, as defined in this study. [source] Clinical trial: multispecies probiotic supplementation alleviates the symptoms of irritable bowel syndrome and stabilizes intestinal microbiotaALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2008K. KAJANDER Summary Background, Irritable bowel syndrome is the most common diagnosis in gastroenterology. Trials suggest certain probiotics to be beneficial. Aim, To investigate the effects of multispecies probiotic supplementation (Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium animalis ssp. lactis Bb12) on abdominal symptoms, quality of life, intestinal microbiota and inflammatory markers in irritable bowel syndrome. Methods, Eighty-six irritable bowel syndrome patients (Rome II criteria) participated in this randomized, placebo-controlled 5-month intervention. Patients were randomized to receive daily either multispecies probiotic supplementation or placebo. Irritable bowel syndrome symptoms, quality of life, microarray-based intestinal microbiota stability (n = 20), serum cytokines and sensitive C-reactive protein were monitored. Results, The composite irritable bowel syndrome score had at 5 months decreased 14 points (95% CI: ,19 to ,9) from baseline with the multispecies probiotic vs. three points (95% CI: ,8 to 1) with placebo (P = 0.0083). Especially, distension and abdominal pain were affected. A stabilization of the microbiota was observed, as the microbiota similarity index increased with the probiotic supplementation (1.9 ± 3.1), while it decreased with placebo (,2.9 ± 1.7). No differences were seen in C-reactive protein. Conclusions, This multispecies probiotic seems to be an effective and safe option to alleviate symptoms of irritable bowel syndrome, and to stabilize the intestinal microbiota. [source] Review article: prebiotics in the gastrointestinal tractALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2006S. MACFARLANE Summary Background Prebiotics are short-chain carbohydrates that alter the composition, or metabolism, of the gut microbiota in a beneficial manner. It is therefore expected that prebiotics will improve health in a way similar to probiotics, whilst at the same time being cheaper, and carrying less risk and being easier to incorporate into the diet than probiotics. Aim To review published evidence for prebiotic effects on gut function and human health. Methods We searched the Science Citation Index with the terms prebiotic, microbiota, gut bacteria, large intestine, mucosa, bowel habit, constipation, diarrhoea, inflammatory bowel disease, Crohn's disease, ulcerative colitis, pouchitis, calcium and cancer, focussing principally on studies in humans and reports in the English language. Search of the Cochrane Library did not identify any clinical study or meta-analysis on this topic. Results Three prebiotics, oligofructose, galacto-oligosaccharides and lactulose, clearly alter the balance of the large bowel microbiota by increasing bifidobacteria and Lactobacillus numbers. These carbohydrates are fermented and give rise to short-chain fatty acid and intestinal gas; however, effects on bowel habit are relatively small. Randomized-controlled trials of their effect in a clinical context are few, although animal studies show anti-inflammatory effects in inflammatory bowel disease, while calcium absorption is increased. Conclusions It is still early days for prebiotics, but they offer the potential to modify the gut microbial balance in such a way as to bring direct health benefits cheaply and safely. [source] Lactobacilli antagonize biological effects of enterohaemorrhagic Escherichia coli in vitroLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2008A.A. Hugo Abstract Aims:, To assess the effect of two lactobacilli on the biological activity of enterohaemorrhagic Escherichia coli (EHEC) in vitro. Methods and Results:, Strains CIDCA 133 (Lactobacillus delbrueckii subsp. lactis) and CIDCA 83114 (Lactobacillus plantarum) were studied. Hep-2 cells were used as an in vitro model to assess the biological effect of a clinical isolate of EHEC. Preincubation of cell monolayers with lactobacilli before EHEC prevented detachment of eukaryotic cells and minimizes both F-actin rearrangements and morphological alterations. Interestingly, the protective effect could not be ascribed to pathogen exclusion. In addition, viability of the lactobacilli was not necessary for protection and other species of the genus Lactobacillus failed to protect eukaryotic cells. Conclusions:, Our results suggest that lactobacilli are antagonizing virulence mechanisms of EHEC either by modification of the microenvironment or by interfering with the signalling cascades triggered by the pathogen. Significance and Impact of the Study:, Our findings give a rationale basis for the use of specific probiotic strains for the prophylaxis and prevention of intestinal infections due to EHEC. [source] | |||||||||||||||||||||||||||||||