Immunologic Quality Improvement of Racing Pigeon Squabs through Induction of Cropmilk using Probiotic Lactobacillus sp.

Probiotic is live microbial cells supplementation that has beneficial effect to the host. Feeding adult pigeons (Columba livia) with food supplemented with probiotic, Lactobacillus sp., at concentration 106,108, and 1010 cells g-1 respectively have been done in order to improve the immunologic quality of the squabs. Immunologic response namely the number and activity of kidney’s macrophage were examined. Also, the pathologic signs which developed following artificial infection by intramuscular injection with Escherichia coli suspension was examined. The result indicated that adult pigeon feed with food containing probiotic have beneficial effect to the squabs (through cropmilk) by improving their immune response namely increasing the number of kidney’s macrophage and their in vitro phagocytic activity. Also, it reduced the E. coli population in the squabs’ gut. (Animal Production 6(2): 11-124 (2004) Key Words: pigeon squab, probiotic, Lactobacillus sp., immune response

The development of Lactococcus lactis as an antimicrobial agent

Non-pathogenic lactic acid bacteria are economically important Gram-positive bacteria used extensively in the food industry. Due to their “generally regarded as safe” status, certain species from the genera Lactobacillus and Lactococcus are also considered desirable as candidates for the production and secretion of recombinant proteins, particular those with therapeutic applications. The hypothesis examined by this thesis is that Lactococcus lactis can be modified to be an effective antimicrobial agent. Therefore, the aims of this thesis were to investigate the optimisation of the expression, secretion and/or activities of potential heterologous antimicrobial proteins by the model lactic acid bacterium, Lactococcus lactis subsp. cremoris MG1363. L. lactis strains were engineered to express and secrete the recombinant CyuC surface protein from Lactobacillus reuteri BR11, and a fusion protein consisting of CyuC and lysostaphin using the Sep promoter and secretion signal. CyuC has been characterised as a cystine-binding protein, but has also been demonstrated to have fibronectin binding activity. Lysostaphin is a bacteriolytic enzyme with specific activity against the Gram-positive pathogen, Staphylococcus aureus. These modified L. lactis strains were then investigated to see if they had the ability to inhibit the adhesion of S. aureus to host extracellular matrix (ECM) proteins. It was observed that the cell extracts of the L. lactis strain with the vector only (pGhost9:ISS1) was able to inhibit the adhesion of S. aureus to fibronectin, whilst the cell extracts of the L. lactis strain expressing lysostaphin was able to inhibit adhesion to keratin. Finally, this thesis has identified specific lactococcal genes that affect the secretion of lysostaphin through the use of random transposon mutagenesis. Ten mutants with higher lysostaphin activity contained insertions in four different genes encoding: (i) an uncharacterised putative transmembrane protein (llmg_0609), (ii) an enzyme catalysing the first step in peptidoglycan biosynthesis (murA2), (iii) a homolog of the oxidative defence regulator (trmA), and (iv) an uncharacterised putative enzyme involved in ubiquinone biosynthesis (llmg_2148). The higher lysostaphin activity observed in these mutants was found to be due to higher amounts of lysostaphin being secreted. The findings of this thesis contribute to the development of this organism as an antimicrobial agent and also to our understanding of L. lactis genetics.

Microbial colonisation of human follicular fluid and adverse in vitro fertilisation outcomes

This study, investigating 263 women undergoing trans-vaginal oocyte retrieval for in vitro fertilisation (IVF) found that microorganisms colonising follicular fluid contributed to adverse IVF (pre-implantation) and pregnancy (post-implantation) outcomes including poor quality embryos, failed pregnancy and early pregnancy loss (< 37 weeks gestation). Some microorganisms also showed in vitro growth patterns in liquid media that appeared to be enhanced by the hormonal stimulation protocol used for oocyte retrieval. Elaborated cytokines within follicular fluid were also associated with adverse IVF outcomes. This study is imperative because infertility affects 16% of the human population and the numbers of couples needing assistance continues to increase. Despite significant improvements in the technical aspects of assisted reproductive technologies (ART), the live birth rate has not increased proportionally. Overt genital tract infection has been associated with both infertility and adverse pregnancy outcomes (including miscarriage and preterm birth) as a direct result of the infection or the host response to it. Importantly, once inflammation had become established, medical treatment often failed to prevent these significant adverse outcomes. Current evaluations of fertility focus on the ovary as a site of steroid hormone production and ovulation. However, infertility as a result of subclinical colonisation of the ovary has not been reported. Furthermore, identification of the microorganisms present in follicular fluid and the local cytokine profile may provide clinicians with an early indication of the prognosis for IVF treatment in infertile couples, thus allowing antimicrobial treatment and/or counselling about possible IVF failure. During an IVF cycle, multiple oocytes undergo maturation in vivo in response to hormonal hyperstimulation. Oocytes for in vitro insemination are collected trans-vaginally. The follicular fluid that bathes the maturing oocyte in vivo, usually is discarded as part of the IVF procedure, but provides a unique opportunity to investigate microbial causes of adverse IVF outcomes. Some previous studies have identified follicular fluid markers that predict IVF pregnancy outcomes. However, there have not been any detailed microbiological studies of follicular fluid. For this current study, paired follicular fluid and vaginal secretion samples were collected from women undergoing IVF cycles to determine whether microorganisms in follicular fluid were associated with adverse IVF outcomes. Microorganisms in follicular fluid were regarded as either "colonisers" or "contaminants"; colonisers, if they were unique to the follicular fluid sample, and contaminants if the same microorganisms were detected in the vaginal and follicular fluid samples indicating that the follicular fluid was merely contaminated during the oocyte retrieval process. Quite unexpectedly, by these criteria, we found that follicular fluid from approximately 30% of all subjects was colonised with bacteria. Fertile and infertile women with colonised follicular fluid had decreased embryo transfer rates and decreased pregnancy rates compared to women with contaminated follicular fluids. The observation that follicular fluid was not always sterile, but contained a diverse range of microorganisms, is novel. Many of the microorganisms we detected in follicular fluid are known opportunistic pathogens that have been detected in upper genital tract infections and are associated with adverse pregnancy outcomes. Bacteria were able to survive for at least 28 weeks in vitro, in cultures of follicular fluid. Within 10 days of establishing these in vitro cultures, several species (Lactobacillus spp., Bifidobacterium spp., Propionibacterium spp., Streptococcus spp. and Salmonella entericus) had formed biofilms. Biofilms play a major role in microbial pathogenicity and persistence. The propensity of microbial species to form biofilms in follicular fluid suggests that successful treatment of these infections with antimicrobials may be difficult. Bifidobacterium spp. grew, in liquid media, only if concentrations of oestradiol and progesterone were similar to those achieved in vivo during an IVF cycle. In contrast, the growth of Streptococcus agalactiae and Escherichia coli was inhibited or abolished by the addition of these hormones to culture medium. These data suggest that the likelihood of microorganisms colonising follicular fluid and the species of bacteria involved is influenced by the stage of the menstrual cycle and, in the case of IVF, the nature and dose of steroid hormones administered for the maturation of multiple oocytes in vivo. Our findings indicate that the elevated levels of steroid hormones during an IVF cycle may influence the microbial growth within follicular fluid, suggesting that the treatment itself will impact on the microflora present in the female upper genital tract during pre-conception and early post-conception phases of the cycle. The effect of the host immune response on colonising bacteria and on the outcomes of IVF also was investigated. White blood cells reportedly compose between 5% and 15% of the cell population in follicular fluid. The follicular membrane is semi-permeable and cells are actively recruited as part of the normal menstrual cycle and in response to microorganisms. A previous study investigated follicular fluid cytokines from infertile women and fertile oocyte donors undergoing IVF, and concluded that there were no significant differences in the cytokine concentrations between the two groups. However, other studies have reported differences in the follicular fluid cytokine levels associated with infertile women with endometriosis or polycystic ovary syndrome. In this study, elevated levels of interleukin (IL)-1 á, IL-1 â and vascular endothelial growth factor (VEGF) in vaginal fluid were associated with successful fertilisation, which may be useful marker for successful fertilisation outcomes for women trying to conceive naturally or prior to oocyte retrieval for IVF. Elevated levels of IL-6, IL-12p40, granulocyte colony stimulating factor (GCSF) and interferon-gamma (IFN ã) in follicular fluid were associated with successful embryo transfer. Elevated levels of pro-inflammatory IL-18 and decreased levels of anti-inflammatory IL-10 were identified in follicular fluid from women with idiopathic infertility. Successful fertilisation and implantation is dependent on a controlled pro-inflammatory environment, involving active recruitment of pro-inflammatory mediators to the genital tract as part of the menstrual cycle and early pregnancy. However, ongoing pregnancy requires an enhanced anti-inflammatory environment to ensure that the maternal immune system does not reject the semi-allergenic foetus. The pro-inflammatory skew in the follicular fluid of women with idiopathic infertility, correlates with normal rates of fertilisation, embryo discard and embryo transfer, observed for this cohort, which were similar to the outcomes observed for fertile women. However, their pregnancy rate was reduced compared to fertile women. An altered local immune response in follicular fluid may provide a means of explaining infertility in this cohort, previously defined as 'idiopathic'. This study has found that microorganisms colonising follicular fluid may have contributed to adverse IVF and pregnancy outcomes. Follicular fluid bathes the cumulus oocyte complex during the in vivo maturation process, and microorganisms in the fluid, their metabolic products or the local immune response to these microorganisms may result in damage to the oocytes, degradation of the cumulus or contamination of the IVF culture system. Previous studies that have discounted bacterial contamination of follicular fluid as a cause of adverse IVF outcomes failed to distinguish between bacteria that were introduced into the follicular fluid at the time of trans-vaginal oocyte retrieval and those that colonised the follicular fluid. Those bacteria that had colonised the fluid may have had time to form biofilms and to elicit a local immune response. Failure to draw this distinction has previously prevented consideration of bacterial colonisation of follicular fluid as a cause of adverse IVF outcomes. Several observations arising from this study are of significance to IVF programs. Follicular fluid is not always sterile and colonisation of follicular fluid is a cause of adverse IVF and pregnancy outcomes. Hormonal stimulation associated with IVF may influence whether follicular fluid is colonised and enhance the growth of specific species of bacteria within follicular fluid. Bacteria in follicular fluid may form biofilms and literature has reported that this may influence their susceptibility to antibiotics. Monitoring the levels of selected cytokines within vaginal secretions may inform fertilisation outcomes. This study has identified novel factors contributing to adverse IVF outcomes and that are most likely to affect also natural conception outcomes. Early intervention, possibly using antimicrobial or immunological therapies may reduce the need for ART and improve reproductive health outcomes for all women.

Hormone-dependent bacterial growth persistence and biofilm formation - A pilot study investigating human follicular fluid collected during IVF cycles

Human follicular fluid, considered sterile, is aspirated as part of an in vitro fertilization (IVF) cycle. However, it is easily contaminated by the trans-vaginal collection route and little information exists in its potential to support the growth of microorganisms. The objectives of this study were to determine whether human follicular fluid can support bacterial growth over time, whether the steroid hormones estradiol and progesterone (present at high levels within follicular fluid) contribute to the in vitro growth of bacterial species, and whether species isolated from follicular fluid form biofilms. We found that bacteria in follicular fluid could persist for at least 28 weeks in vitro and that the steroid hormones stimulated the growth of some bacterial species, specifically Lactobacillus spp., Bifidobacterium spp. Streptococcus spp. and E. coli. Several species, Lactobacillus spp., Propionibacterium spp., and Streptococcus spp., formed biofilms when incubated in native follicular fluids in vitro (18/24, 75%). We conclude that bacteria aspirated along with follicular fluid during IVF cycles demonstrate a persistent pattern of growth. This discovery is important since it can offer a new avenue for investigation in infertile couples.

Microorganisms within human follicular fluid : effects on IVF

Our previous study reported microorganisms in human follicular fluid. The objective of this study was to test human follicular fluid for the presence of microorganisms and to correlate these findings with the in vitro fertilization (IVF) outcomes. In this study, 263 paired follicular fluids and vaginal swabs were collected from women undergoing IVF cycles, with various causes for infertility, and were cultured to detect microorganisms. The cause of infertility and the IVF outcomes for each woman were correlated with the microorganisms detected within follicular fluid collected at the time of trans-vaginal oocyte retrieval. Microorganisms isolated from follicular fluids were classified as: (1) ‘colonizers’ if microorganisms were detected within the follicular fluid, but not within the vaginal swab (at the time of oocyte retrieval); or (2) ‘contaminants’ if microorganisms detected in the vagina at the time of oocyte retrieval were also detected within the follicular fluid. The presence of Lactobacillus spp. in ovarian follicular fluids was associated with embryo maturation and transfer. This study revealed microorganisms in follicular fluid itself and that the presence of particular microorganisms has an adverse affect on IVF outcomes as seen by an overall decrease in embryo transfer rates and pregnancy rates in both fertile and infertile women, and live birth rates in women with idiopathic infertility. Follicular fluid microorganisms are a potential cause of adverse pregnancy outcomes in IVF in both infertile women and in fertile women with infertile male partners.

TUNEL analysis of DNA fragmentation in mouse unfertilized oocytes : the effect of microorganisms within human follicular fluid collected during IVF cycles

Recently we reported the presence of bacteria within follicular fluid. Previous studies have reported that DNA fragmentation in human spermatozoa after in vivo or in vitro incubation with bacteria results in early embryo demise and a reduced rate of ongoing pregnancy, but the effect of bacteria on oocytes is unknown. This study examined the DNA within mouse oocytes after 12 hours’ incubation within human follicular fluids (n = 5), which were collected from women undergoing in vitro fertilization (IVF) treatment. Each follicular fluid sample was cultured to detect the presence of bacteria. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) was used to label DNA fragmentation in ovulated, non-fertilized mouse oocytes following in vitro incubation in human follicular fluid. The bacteria Streptococcus anginosus and Peptoniphilus spp., Lactobacillus gasseri (low-dose), L. gasseri (high-dose), Enterococcus faecalis, or Propionibacterium acnes were detected within the follicular fluids. The most severe DNA fragmentation was observed in oocytes incubated in the follicular fluids containing P. acnes or L. gasseri (high-dose). No DNA fragmentation was observed in the mouse oocytes incubated in the follicular fluid containing low-dose L. gasseri or E. faecalis. Low human oocyte fertilization rates (<29%) were associated with extensive fragmentation in mouse oocytes (80–100%). Bacteria colonizing human follicular fluid in vivo may cause DNA fragmentation in mouse oocytes following 12 h of in vitro incubation. Follicular fluid bacteria may result in poor quality oocytes and/or embryos, leading to poor IVF outcomes.

Randomized controlled trial : a randomized controlled clinical trial comparing a remineralizing paste with an antibacterial gel to prevent early childhood caries

PURPOSE: The purpose of this study was to compare twice daily tooth-brushing using 0.304 percent fluoride toothpaste alone with: (1) twice daily tooth-brushing plus once daily 10% casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste; and (2) twice daily tooth-brushing plus once daily 0.12% chlorhexidine gel (CHX) for reducing early childhood caries (ECC) and mutans streptococci (MS) colonization. METHODS: Subjects (n=622) recruited at birth were randomized to receive either CPP-ACP or CHX or no product (study control [SC]). All children were examined at 6, 12, and 18 months old in their homes, and at 24 months old in a community dental clinic. RESULTS: At 24 months old, the caries incidence was 1% (2/163) in CPP-ACP, 2% (4/180) in CHX, and 2% (3/188) in SC groups. In children who were previously MS colonized at 12 and 18 months old, 0% (0/11) and 5% (3/63), respectively, of the CPP-ACP group remained MS-positive versus 22% (2/9) and 72% (18/25) in CHX and 16% (4/25) and 50% (7/14) in SC groups (P<.001). CONCLUSIONS: There is insufficient evidence to justify the daily use of casein phosphopeptide-amorphous calcium phosphate or chlorhexidine gel to control early childhood caries.

New approaches to making the microenvironment of the female reproductive tract hostile to HIV

The studies presented in this review explore three distinct areas with potential for inhibiting HIV infection in women. Based on emerging information from the physiology, endocrinology and immunology of the female reproductive tract (FRT), we propose unique 'works in progress' for protecting women from HIV. Various aspects of FRT immunity are suppressed by estradiol during the menstrual cycle, making women more susceptible to HIV infection. By engineering commensal Lactobacillus to secrete the anti-HIV molecule Elafin as estradiol levels increase, women could be protected from HIV infection. Selective estrogen response modifiers enhance barrier integrity and enhance secretion of protective anti-HIV molecules. Finally, understanding the interactions and regulation of FRT endogenous antimicrobials, proteases, antiproteases, etc., all of which are under hormonal control, will open new avenues to therapeutic manipulation of the FRT mucosal microenvironment. By seeking new alternatives to preventing HIV infection in women, we may finally disrupt the HIV pandemic.

Does the microbiome play a causal role in spondyloarthritis?

The purpose of this study is to review the potential causal role of the microbiome in the pathogenesis of spondyloarthritis. The method used for the study is literature review. The microbiome plays a major role in educating the immune response. The microbiome is strongly implicated in inflammatory bowel disease which has clinical and genetic overlap with spondyloarthritis. The microbiome also plays a causal role in bowel and joint disease in HLA B27/human beta 2 microglobulin transgenic rats. The mechanism(s) by which HLA B27 could influence the microbiome is unknown but theories include an immune response gene selectivity, an effect on dendritic cell function, or a mucosal immunodeficiency. Bacteria are strongly implicated in the pathogenesis of spondyloarthritis. Studies to understand how HLA B27 affects bacterial ecosystems should be encouraged.

Evaluation of Inoculated Lablab Silage for Growing Dairy Heifers

A summer grown forage legume crop – Lablab (Lablab purpureus) harvested in autumn, was ensiled as plastic wrapped, large round bales. Of the 30 bales produced, 13 were inoculated with a bacterial inoculant containing Lactobacillus plantarum and Enterococcus faecium. Inoculant was premixed at 30 g/litre water, cultured overnight (18 hours) then sprayed onto cut forage during the baling and wrapping procedure at 1 litre per tonne of silage. A replicated feeding experiment was conducted in July - August 1998 (5 weeks), using 24 eight month old Holstein Friesian heifers group fed non-inoculated or inoculated silage to appetite plus 2 kg rolled sorghum grain/heifer.day. Chemical composition and nutritive value of well preserved bales of control and inoculated silages were similar (P>0.05) with 50% DM and 26 g N and 6.8 MJ ME per kg DM. Lactic acid and acetic acid concentrations were 11.4 v. 11.4 and 4.90 v. 3.75 g/kg DM for control and inoculated silages respectively (P>0.05). Heifers preferentially selected leaf from the silage offered and maintained liveweight gains of 0.70 and 0.61 kg/day respectively (P>0.05) during the silage feeding period. High DM and low WSC content of the parent forage may have reduced the opportunity for the bacterial inoculant to have effect. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Breastmilk-saliva interactions boost innate immunity by regulating the oral microbiome in early infancy

Introduction Xanthine oxidase (XO) is distributed in mammals largely in the liver and small intestine, but also is highly active in milk where it generates hydrogen peroxide (H2O2). Adult human saliva is low in hypoxanthine and xanthine, the substrates of XO, and high in the lactoperoxidase substrate thiocyanate, but saliva of neonates has not been examined. Results Median concentrations of hypoxanthine and xanthine in neonatal saliva (27 and 19 μM respectively) were ten-fold higher than in adult saliva (2.1 and 1.7 μM). Fresh breastmilk contained 27.3±12.2 μM H2O2 but mixing baby saliva with breastmilk additionally generated >40 μM H2O2, sufficient to inhibit growth of the opportunistic pathogens Staphylococcus aureus and Salmonella spp. Oral peroxidase activity in neonatal saliva was variable but low (median 7 U/L, range 2–449) compared to adults (620 U/L, 48–1348), while peroxidase substrate thiocyanate in neonatal saliva was surprisingly high. Baby but not adult saliva also contained nucleosides and nucleobases that encouraged growth of the commensal bacteria Lactobacillus, but inhibited opportunistic pathogens; these nucleosides/bases may also promote growth of immature gut cells. Transition from neonatal to adult saliva pattern occurred during the weaning period. A survey of saliva from domesticated mammals revealed wide variation in nucleoside/base patterns. Discussion and Conclusion During breast-feeding, baby saliva reacts with breastmilk to produce reactive oxygen species, while simultaneously providing growth-promoting nucleotide precursors. Milk thus plays more than a simply nutritional role in mammals, interacting with infant saliva to produce a potent combination of stimulatory and inhibitory metabolites that regulate early oral–and hence gut–microbiota. Consequently, milk-saliva mixing appears to represent unique biochemical synergism which boosts early innate immunity.

Immunomodulatory effects of probiotic bacteria in healthy adults

Probiooteilla kantakohtaisia vaikutuksia ihmisen immuunijärjestelmään terveillä aikuisilla Probiooteilla on kantakohtaisia tulehduksen välittäjäaineita vähentäviä vaikutuksia ja probioottien yhdistelmien vaikutukset eroavat yksittäisten kantojen vaikutuksista selviää TtM Riina Kekkosen tuoreesta väitöstutkimuksesta. TtM Riina Kekkonen on selvittänyt väitöskirjassaan eri probioottikantojen vaikutuksia immuunivasteeseen valkosolumallissa sekä terveillä aikuisilla lumekontrolloiduissa kliinisissä tutkimuksissa. Aikaisemmin probioottien vaikutuksia on tutkittu lähinnä allergian ja erilaisten vatsavaivojen ehkäisyssä ja hoidossa. Probiootteja sisältäviä tuotteita käyttävät kuluttajat ovat kuitenkin useimmiten terveitä aikuisia, ja probioottien vaikutus terveiden aikuisten immuunijärjestelmään on ollut puutteellisesti selvitettyä. Valkosolumallissa probioottikantojen havaittiin poikkeavan toisistaan niiden kyvyssä aktivoida immuunivasteen välittäjäaineiden, sytokiinien, tuotantoa. Anti-inflammatorisia, eli tulehdusta lievittäviä vaikutuksia nähtiin lähinnä Bifidobacterium ja Propionibacterium sukuihin kuuluvilla kannoilla. Streptococcus ja Leuconostoc sukuihin kuuluvat kannat puolestaan aktivoivat Th1 tyyppistä, soluvälitteistä immuunivastetta. Eri probioottien kombinaatiot eivät saaneet aikaan voimakkaampaa aktivaatiota yksittäisiin kantoihin verrattuna, joka viittaa probioottien keskinäiseen kilpailuun niiden ollessa kontaktissa ihmisen solujen kanssa. Probioottikantojen valinta kliinisiin tutkimuksiin tehtiin niiden anti-inflammatoristen ominaisuuksien perusteella. Parhaita anti-inflammatorisia kantoja olivat B. lactis ssp. animalis Bb12 ja P. freudenreichii ssp. shermanii JS, joiden lisäksi tutkimuksiin valittiin myös L. rhamnosus GG (LGG) hyvin tutkittuna referenssikantana. Solutöiden tulokset eivät olleet täysin verrannollisia kliinisen työn tuloksiin, koska LGG näytti omaavan parhaat anti-inflammatoriset ominaisuudet kliinisissä tutkimuksissa vaikka solutyössä sen aikaansaamat vasteet olivat melko vaimeita. Kolmen viikon kliinisessä tutkimuksessa terveillä aikuisilla LGG alensi mm. tulehdusta kuvaavan C-reaktiivisen proteiinin ja inflammatoristen sytokiinien määrää. Pidemmässä kolmen kuukauden pituisessa kliinisessä tutkimuksessa LGG:llä ei ollut vaikutusta terveiden aikuisten infektiosairastavuuteen, mutta LGG lyhensi vatsavaivojen kestoa. Probioottien vaikutukset immuunijärjestelmään näyttävät olevan kantakohtaisia ja erityisesti Lactobacillus rhamnosus GG:llä havaittiin anti-inflammatorisia vaikutuksia. Valkosolumallia ei tulisi käyttää ainoana probioottikantojen skriinausmenetelmänä niiden immunologisia vaikutuksia selvitettäessä, koska solutöiden tulokset eivät olleet täysin verrannollisia kliinisten tutkimusten tuloksiin. Sen sijaan veren perifeeristen lymfosyyttien eristäminen ja niiden aktivoitumisen selvittäminen lyhytaikaisessa kliinisessä tutkimuksessa voisi toimia suhteellisen helppona skiinausmenetelmänä.

The role of probiotics in Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is a major cause of chronic gastritis and peptic ulcer disease, and it is also designated as a class-I carcinogen for stomach cancer. The role of probiotics in the treatment of gastrointestinal infections is increasingly documented as an alternative or complement to antibiotics, with the potential to decrease the use of antibiotics or reduce their adverse effects. These studies were conducted to investigate the role of probiotics in the treatment of H. pylori infection. Various aspects included: an investigation of the effects of a probiotic combination consisting of Lactobacillus rhamnosus GG, L. rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99 or B. lactis Bb12 as a supplementation to H. pylori eradication therapy, with special reference to tolerability, effectiveness, and microbiota alterations following the treatment; discovering the role of probiotics in vivo with H. pylori infected and uninfected patients, as well as with an in vitro model of H. pylori infection. The probiotic combination therapy was able to reduce significantly the total symptom score, which takes into account both the frequency and the severity of the adverse effects, during the eradication treatment. The supplementation did not improve the success of the eradication treatment significantly, though some difference was seen in the eradication percentages (91% vs. 79%). The quantities of predominant bacterial groups were altered significantly following the triple treatment. Probiotics slightly counteracted the effects of anti-H. pylori treatment, monitored as significantly less alterations in the total numbers of aerobes and lactobacilli/enterococci group bacteria. After probiotic intervention, L. rhamnosus GG adhered to a minority of the patients upper gastrointestinal mucosa, but all of the probiotics survived well through the gastrointestinal tract transit with and without antimicrobial treatment. Probiotic intervention decreased gastrin-17 levels in H. pylori infected patients and appeared to decrease the 13C-urea breath test values. In in vitro Caco-2 cell line experiments, probiotics inhibited H. pylori adhesion to intestinal epithelial cells. Both L. rhamnosus strains, P. freudenreichii ssp. shermanii JS and the combination inhibited the H. pylori-induced acute cell leakage. Simultaneously, both L.rhamnosus strains and the combination transiently improved the epithelial barrier function. The pro-inflammatory effects prevailed when the probiotics were used in combination. According to this series of studies, probiotic combination could have some potential in reducing adverse effects induced by H. pylori eradication treatment and beneficial effects on H. pylori infected subjects.