Probiotic Colonization Research Articles

Influence of probiotic Lactobacilli colonization on neonatal B cell responses in a gnotobiotic pig model of human rotavirus infection and disease

The goal of this study was to define the impact of colonization of gnotobiotic (Gn) pigs with lactic acid bacteria (LAB) on development of intestinal and systemic B cell responses to human rotavirus (HRV). The LAB-specific and total B cell responses were also assessed. Gn pigs were inoculated with LAB ( Lactobacillus acidophilus and L. reuteri) and virulent Wa strain HRV (LAB+HRV+), HRV only (LAB−HRV+), LAB only (LAB+HRV−) or mock (LAB−HRV−). The HRV infection induced similar HRV-specific intestinal and systemic antibody and B cell responses in pigs with or without LAB, whereas LAB significantly enhanced total intestinal IgA secreting cell responses and total serum IgM and intestinal IgM and IgG titers. The LAB colonization did not reduce HRV shedding or diarrhea, this may be partly due to the short time interval between the first LAB feeding and HRV inoculation. Further studies are needed with longer time for LAB to establish before HRV inoculation. However, our studies demonstrate that Gn pigs infected with HRV develop a similar magnitude of virus-specific B cell responses as those of HRV-infected and LAB colonized pigs. LAB colonization alone is not as efficient in promoting intestinal B cell responses, as is HRV infection.

Probiotics: do they have a role in oral medicine and dentistry?

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.

Comparative detection of bacterial adhesion to Caco-2 cells with ELISA, radioactivity and plate count methods

Different methods are used to study bacterial adhesion to intestinal epithelial cells, which is an important step in pathogenic infection as well as in probiotic colonization of the intestinal tract. The aim of this study was to compare the ELISA-based method with more conventional plate count and radiolabeling methods for bacterial adhesion detection. An ELISA-based assay was optimized for the detection of Bifidobacterium longum and Escherichia coli O157:H7, which are low and highly adherent bacteria, respectively. In agreement with previous investigations, a percentage of adhesion below 1% was obtained for B. longum with ELISA. However, high nonspecific background and low positive signals were measured due to the use of polyclonal antibodies and the low adhesion capacity with this strain. In contrast, the ELISA-based method developed for E. coli adhesion detected a high adhesion percentage (15%). For this bacterium the three methods tested gave similar results for the highest bacterial concentrations (6.8 Log CFU added bacteria/well). However, differences among methods increased with the addition of decreased bacterial concentration due to different detection thresholds (5.9, 5.6 and 2.9 Log CFU adherent bacteria/well for radioactivity, ELISA and plate count methods, respectively). The ELISA-based method was shown to be a good predictor for bacterial adhesion compared to the radiolabeling method when good quality specific antibodies were used. This technique is convenient and allows handling of numerous samples.

Probiotics and prebiotics: Where are we going?Edited by Gerald W. Tannock. 341 pp. $180. Caister Academic Press, Norfolk, United Kingdom, 2002. ISBN 0-9542464-1-1. Web address for ordering: www.caister.com

Intestinal microflora and probiotic therapy have attracted increasing attention, both in the scientific community, where it is stimulating promising new research, as well as in the consumer market, where food and dietary supplements comprise a growing portion of the self-care health market. As our understanding of the interactions between gut microflora and their host advances, the potential impact of probiotics and prebiotics on human health will develop accordingly. Written by authoritative experts, Probiotics and Prebiotics: Where Are We Going? provides an historical perspective on intestinal microflora and probiotic use, and highlights future directions. The breadth of this reference is impressive, spanning from discussions on genomics of probiotic organisms to reviews on clinical disease prevention with prebiotics. In the initial chapter, the author provides a thorough historical perspective on concepts related to intestinal microecology dating back to Elie Metchnikoff (1845–1916), now considered the inventor of probiotics. The uniqueness of human gut microflora, and the prinicipal of homeostasis, which accounts for the transient nature of probiotic colonization, are major points of emphasis. Brief single sentence synopses at the completion of each section provide useful “take-home” points. Following the introductory chapter, the next several sections cover current techniques involved in identification of intestinal microorganisms, including PCR-based denaturing gradient gel electrophoresis (DGGE), fluorescent in situ hybridization, and terminal-restriction fragment length polymorphism (T-RFLP). The depth to which these technologies are discussed may be useful to those involved in hands-on microbiologic investigation but is clearly beyond the scope of those without such a background. Additional chapters address the role of prebiotics, a much more recent development in dietary intervention, as regulators of the gut ecosystem. Specifically discussed are the established and putative effects of prebiotics on health, including anti-colon cancer properties, lipid-lowering action, improved calcium bioavailability, and enhanced resistance to invading pathogens. The topic of “targeted prebiotics” selectively fermented by particular species of Bifidobacterium and Lactobacillus is introduced as a consideration for several varied applications. Also reviewed are manufacturing technologies for the production of functional carbohydrates, perhaps somewhat beyond the scope of a reference intending to cover the role of gut microflora in health and disease. The text also addresses the influence of the gut microflora on the development of the immune system, specifically as it relates to inflammatory bowel diseases (IBD) and atopic disorders. A thorough summary of in vitro and in vivo data investigating possible therapeutic mechanisms, as well as the clinical efficacy of probiotic microorganisms relevant to inflammatory bowel diseases serves as an excellent resource. Even the infectious etiology theory of Crohn’s disease is touched upon, via a brief overview of data regarding possible disease-initiating and perpetuating microorgansisms. Appropriately, an entire chapter is devoted to the evidence supporting a protective role of microbial colonization against the development of allergic/atopic diseases, and includes a brief look at the epidemiologic basis of the Hygeine Hypothesis. In the final chapter, the expanding role of functional genomics and genetic characterization of particular microorganisms was introduced as a critical means to unequivocally define their contributions to human health. This multifaceted text, which covers topics ranging from intestinal bacteriology identification techniques to the role of probiotic therapy in IBD, will appeal to a wide audience, from microbiologists to food scientists. Clinical gastroenterologists, however, may find the extensive portion of this text devoted to gut microbiology of limited applicability. Bottom Line: A comprehensive review of a timely subject, but with only a few chapters of clinical relevance to gastroenterology practice.

Role of probiotics in the management of patients with food allergy

This review will concentrate on the potential use of probiotics in treating or preventing allergic disorders of the gastro-intestinal tract. In small infants, most reactions to foods are manifested in the gastro-intestinal tract. As children get older, cutaneous and even systemic or respiratory manifestations of food intolerances may be more common. In most instances, allergic disorders in the gut cause inflammation in the mucosa. Recently, the role of gut microflora in allergic disease has gained increasing interest with reports of probiotics being used to treat food allergy. Pertinent scientific reports on the role of probiotics in the management of patients with food allergy will be reviewed. A recent study to determine the effect of very early probiotic colonization will be extensively reviewed as it presents an intriguing concept of a preventive strategy related to food allergy development Significant improvement has been noted in infants receiving Lactobacillus GG in their extensively hydrolyzed formula. It is likely more studies will be forthcoming with different probiotic organisms in the prevention and treatment of allergic disorders in children and adults.

Natural history of colitis and associated epithelial dysfunction in conventionally housed Mdrla-/-mice

ism and host cells Using a T84 cell culture model, we have analyzed the elti:cts of EcN on the epithelial transcriptom, especially on the expre~ion of genes directly affecting an immediate cellular reacnon utilizmg the NF-kB signaling pathway and its control on the transcription of inBammatory cytokines, Selected from 300 differentially regulated genes we are currently investigating five upregulated and three downregulared genes in further detail by Real-Time PCR. In addition, we could show that exposute of T84 ceils to EcN also affected genes revolved in the regulation of the barrier flmction of the intestinal epithelium. Further studies are in progress to increase our knowledge about expression profiles in epithelial cells depending on probiotic colonization. This will not only lead to a better understanding of the mode of action of probiotic strains, such as EcN, but also to the development of new strategies in the treatment of ini?ctions and inflammatory bowel diseases

Colonization of congenitally immunodeficient mice with probiotic bacteria.

We assessed the capacity of four probiotic bacteria (Lactobacillus acidophilus, Lactobacillus reuteri, Lactobacillus casei GG, and Bifidobacterium animalis) to colonize, infect, stimulate immune responses in, and affect the growth and survival of congenitally immunodeficient gnotobiotic beige-athymic (bg/bg-nu/nu) and beige-euthymic (bg/bg-nu/+) mice. The bacteria colonized and persisted, in pure culture, in the alimentary tracts of both mouse strains for the entire study period (12 weeks). Although all adult and neonatal beige-euthymic mice survived probiotic colonization, some infant mortality occurred in beige-athymic pups born to mothers colonized with pure cultures of L. reuteri or L. casei GG. The probiotic bacteria manifested different capacities to adhere to epithelial surfaces, disseminate to internal organs, affect the body weight of adult mice and the growth of neonatal mice, and stimulate immune responses. Although the probiotic species were innocuous for adults, these results suggest that caution and further studies to assess the safety of probiotic bacteria for immunodeficient hosts, especially neonates, are required.