Antagonistic activity against Helicobacter pylori infection in vitro by a strain of Enterococcus faecium TM39

Molecular Identification and Selection of Probiotic Strains Able to Reduce the Serum TMAO Level in Mice Challenged with Choline

Trimethylamine oxide (TMAO) originates from trimethylamine (TMA), which is oxidized in the liver by hepatic flavin-containing monooxygenases (FMO3). TMA is produced by its dietary precursors such as choline, carnitine, and phosphatidylcholine by gut microbiota. TMAO attracts attention, identified as a novel and independent risk factor for promoting obesity, atherosclerosis and cardiovascular disease (CVD), chronic kidney disease (CKD), insulin tolerance, and colon cancer. Probiotics have been considered as live microorganisms, providing benefits to their host when they are given in sufficient quantities and administered continuously. The objective of this study is to suggest a method to select potential probiotic strains to reduce the serum concentration of TMAO in mice fed with choline. In this work, we chose three lactobacilli with strong adherence capability, and fed multistrain formula (MF) to the mice challenged with choline. On days 7, 14, and day 28, it was found that the MF-containing L. amylovorus LAM1345, Lpb. plantarum LP1145, and Lim. fermentum LF33 showed a significant reduction in serum TMAO and TMA levels. For the single strains, LP1145 reduced TMAO on days 14 and 28, and strain LAM1345 reduced TMAO significantly on days 7 and day 14. For strain LF1143 from strain LF33, it showed no significant effect on TMAO and TMA. Thus, MF showed the best effect, which may be due to the additive and synergetic effect and the contribution of strain LP1145 and LAM1345. Finally, for the LAM1345 and LP1145 strains, we used molecular identification and typing methods to assure that these two strains are unique strains. The methods used for LAM 1345 were leader peptidase A (lepA) gene analysis and phylogenetic analysis, while for strain LP 1145and other strains of Lpb. plantarum subsp. plantarum sequences were compared using the whole-genome multilocus sequence typing (wgMLST) method.

In vitro and in vivo inhibition of Helicobacter pylori by Lactobacillus plantarum pH3A, monolaurin, and grapefruit seed extract

Helicobacter pylori infection is the most common cause of gastritis and gastric ulcers. Considering the severe side effects of current antibiotic therapies, it is crucial to find an alternate treatment for H. pylori infection. In this study, we investigated the anti-H. pylori effects of a newly isolated strain of Lactobacillus plantarum (pH3A), monolaurin, grapefruit seed extract (GSE), and their synergies in vitro and in vivo. Monolaurin and GSE suppressed H. pylori growth and urease activity at a minimal inhibitory concentration (MIC) of 62.5 ppm. Live cells and cell-free culture supernatant (CFCS) of L. plantarum pH3A with or without pH adjustment also significantly inhibited H. pylori growth. Although synergy was not observed between monolaurin and GSE, the addition of CFCS significantly enhanced their anti-H. pylori activities. Moreover, L. plantarum pH3A significantly decreased the ability of H. pylori to adhere to AGS cells and interleukin (IL)-8 production in the H. pylori-stimulated AGS cell line. The addition of GSE or monolaurin strengthened these effects. In the in vivo study, H. pylori colonization of the mouse stomach and total serum IgG production were significantly reduced by L. plantarum pH3A treatment, but the addition of monolaurin or GSE did not contribute to these anti-H. pylori activities. Therefore, the L. plantarum pH3A strain can potentially be applied as an alternative anti-H. pylori therapy, but evidence of its synergy with monolaurin or GSE in vivo is still lacking.

Probiotics as the live microscopic fighters against Helicobacter pylori gastric infections

Background

Helicobacter pylori (H. pylori) is the causative agent of stomach diseases such as duodenal ulcer and gastric cancer, in this regard incomplete eradication of this bacterium has become to a serious concern. Probiotics are a group of the beneficial bacteria which increase the cure rate of H. pylori infections through various mechanisms such as competitive inhibition, co-aggregation ability, enhancing mucus production, production of bacteriocins, and modulating immune response.

Result

In this study, according to the received articles, the anti-H. pylori activities of probiotics were reviewed. Based on studies, administration of standard antibiotic therapy combined with probiotics plays an important role in the effective treatment of H. pylori infection. According to the literature, Lactobacillus casei, Lactobacillus reuteri, Lactobacillus rhamnosus GG, and Saccharomyces boulardii can effectively eradicate H. pylori infection. Our results showed that in addition to decrease gastrointestinal symptoms, probiotics can reduce the side effects of antibiotics (especially diarrhea) by altering the intestinal microbiome.

Conclusion

Nevertheless, antagonist activities of probiotics are H. pylori strain-specific. In general, these bacteria can be used for therapeutic purposes such as adjuvant therapy, drug-delivery system, as well as enhancing immune system against H. pylori infection.

Chitosan Inhibits Helicobacter pylori Growth and Urease Production and Prevents Its Infection of Human Gastric Carcinoma Cells

This study investigated the effects of shrimp chitosan with 95% degree of deacetylation (DD95) in combination with clinical antibiotics on the growth and urease production of Helicobacter pylori. The inhibitory effect of DD95 on the adherence of H. pylori to the human intestinal carcinoma cells (TSGH9201) was also investigated. Five strains of H. pylori, including three standard strains and two strains of clinical isolates were used as the test strains. The inhibitory effects of DD95 on growth and urease production of various strains of H. pylori increased with increasing DD95 concentration and decreasing pH values from pH 6.0 to pH 2.0. Urease activity of H. pylori at pH 2.0 in the presence of 4000 μg/mL of DD95 decreased by 37.86% to 46.53%. In the presence of 50 μg/mL antibiotics of amoxicillin, tetracycline, or metronidazole at pH 6.0 and pH 2.0, H. pylori counts were decreased by 1.51–3.19, and 1.47–2.82 Log CFU/mL, respectively. Following the addition of 4000 μg/mL DD95 into the 50 μg/mL antibiotic-containing culture medium with pH 6.0 and pH 2.0, overall H. pylori counts were strongly decreased by 3.67–7.61 and 6.61–6.70 Log CFU/mL, respectively. Further, DD95 could inhibit the adherence of H. pylori on TSGH 9201 cells, as evidenced by fluorescent microscopy and thus may potentially protect against H. pylori infection.

Characterization and evaluation of lactic acid bacteria from indigenous raw milk for potential probiotic properties

Raw milk contains wide microbial diversity, composed mainly of lactic acid bacteria (LAB), which are used as probiotics in both human and animal husbandry. We isolated, characterized, and evaluated LAB from indigenous Bangladeshi raw milk to assess probiotic potential, including antagonistic activity (against Escherichia coli O157: H7, Enterococcus faecalis, Salmonella Typhimurium, Salmonella Enteritidis, and Listeria monocytogenes), survivability in simulated gastric juice, tolerance to phenol and bile salts, adhesion to ileum epithelial cells, auto- and co-aggregation, hydrophobicity, α-glucosidase inhibitory activity, and antibiotic susceptibility tests. The 4 most promising LAB strains showed probiotic potential and were identified as Lactobacillus casei, Lactobacillus plantarum (which produced plantaricin EF), Lactobacillus fermentum, and Lactobacillus paracasei. These strains inhibited all pathogens tested at various degrees, and competitively excluded pathogens with viable counts of 3.0 to 6.0 log cfu/mL. Bacteriocin, organic acids, and low-molecular-weight substances were mainly responsible for antimicrobial activity by the LAB strains. All 4 LAB strains were resistant to oxacillin and 3 were resistant to vancomycin and streptomycin, with multiple antibiotic resistance indices >0.2. After further in vivo evaluation, these LAB strains could be considered probiotic candidates with application in the food industry.

Characterization of probiotic potential of Bacillus species isolated from a traditional brine pickle

Fermented foods are known for their potential as main source of probiotics. The present study aimed at investigating the probiotic properties of bacteria isolated from fermented mango pickle. Non-hemolytic fermenting microbiota isolated from mango pickle was screened in vitro for their basic probiotic properties such as acid tolerance, bile salt, lysozyme and salt tolerance. They were also tested for their beneficial characters like cholesterol removal, bacterial adhesion to hydrocarbons, auto-aggregation, antimicrobial activity, β-galactosidase activity, exopolysaccharide production and adhesion to HT-29 cell line. Outputs of these parameters were subjected to principal component analysis (PCA) and these results were interpreted to select prospective bacterial isolates that can be used as potential probiotics. Out of eight isolates, PUFSTP35 (Bacillus licheniformis), PUFSTP38 (Bacillus amyloliquefaciens) and PUFSTP39 (Bacillus subtilis) showed similar trend to Weissella cibaria (MTCC 9814) that was used as a reference strain for profiling probiotic properties. B. licheniformis PUFSTP35 from fermented mango pickle appear to be the most potential candidate for use as a beneficial probiotic.

Antimicrobial Activity and Chemical Composition of "Kpètè-Kpètè": A Starter of Benin Traditional Beer Tchoukoutou

The aim of this study was to investigate the antibacterial effect of the crude starter "kpètè-kpètè" and lactic acid bacteria used during the production of "tchoukoutou." To achieve this, a total of 11 lactic acid bacteria and 40 starter samples were collected from four communes. The samples were tested on 29 gram + and - strains by disk diffusion method. The minimum inhibitory and bactericidal concentrations of starter and lactic acid bacteria were determined by conventional methods. Organic acids, sugar, and volatile compounds were determined using the HPLC method. The "kpètè-kpètè" displays a high antibacterial activity against the tested strains. The most sensitive strain was S. epidermidis (12.5 mm) whereas the resistance strain was Proteus mirabilis (8 mm). All the tested ferment has not any inhibitory effect on Enterococcus faecalis. The lactic acid bacteria isolates of Parakou showed the highest (17.48 mm) antibacterial activity whereas the smallest diameter was obtained with the ferment collected from Boukoumbé (9.80 mm). The starters' chemical screening revealed the presence of tannins, anthocyanin flavonoids, triterpenes, steroids, reducing compounds, and mucilage O-glycosides. These compounds are probably the source of recorded inhibition effect. The lactic acid bacteria of the "kpètè-kpètè" could be used to develop a food ingredient with probiotic property.

Colonisation of poultry by Salmonella Enteritidis S1400 is reduced by combined administration of Lactobacillus salivarius 59 and Enterococcus faecium PXN-33

Salmonella Enteritidis remains a significant issue within the poultry industry and one potential solution is to use probiotic bacteria to prevent Salmonella colonisation through competitive exclusion (CE). We demonstrate that combined administration of Lactobacillus salivarius 59 and Enterococcus faecium PXN33 were effective competitive excluders of Salmonella Enteritidis S1400 in poultry. Two models were developed to evaluate the efficacy of probiotic where birds received Salmonella Enteritidis S1400 by a) oral gavage and b) sentinel bird to bird transmission. A statistically significant (p<0.001) 2 log reduction of Salmonella Enteritidis S1400 colonisation was observed in the ileum, caecum and colon at day 43 using combined administration of the two probiotic bacteria. However, no Salmonella Enteritidis S1400 colonisation reduction was observed when either probiotic was administered individually. In the sentinel bird model the combined probiotic administered at days 12 and 20 was more effective than one-off or double administrations at age 1 and 12days. In vitro cell free culture supernatant studies suggest the mechanism of Salmonella Enteritidis S1400 inhibition was due to a reduction in pH by the probiotic bacteria. Our current study provides further evidence that probiotics can significantly reduce pathogenic bacterial colonisation in poultry and that mixed preparation of probiotics provide superior performance when compared to individual bacterial preparations.

The Effect of Probiotic Plus Prebiotic Supplementation on the Tolerance and Efficacy of Helicobacter Pylori Eradication Quadruple Therapy: a Randomized Prospective Double Blind Controlled Trial

BACKGROUND

Standard anti-Helicobacter pylori (H. pylori) treatment fails in the eradication of the organism in almost 10-35% of the patients and has different side effects. Recent studies have proposed that probiotic supplementations with or without prebiotic may improve the eradication rate and diminish the side effects, although it is still a controversial issue. We aimed to investigate the effect of probiotic with prebiotic supplementation on the eradication rate and side effects of anti H. pylori quadruple therapy.

METHODS

76 patients with a positive biopsy specimen for H. pylori were enrolled. They were randomized to receive quadruple therapy of bismuth, clarithromycin, amoxicillin, and omeprazole for 14 days and also the synbiotic or the placebo. We asked them to answer study questionnaires at the beginning and during the treatment. Finally, urea breath test was done 8 weeks after the treatment.

RESULTS

The eradication rate was significantly better in the synbiotic group by intention-to-treat analysis (p<0.05). Treatment side effects such as diarrhea, nausea, vomiting, epigastric pain, flatulence, constipation, and taste abnormality were similar in both groups but anorexia was significantly better in the synbiotic group (p <0.05).

CONCLUSION

The eradication rate was significantly better in the synbiotic group by intention-to-treat analysis (p<0.05). Treatment side effects such as diarrhea, nausea, vomiting, epigastric pain, flatulence, but could improve the eradication by augmenting the treatment tolerance and compliance.

In vitro probiotic profiling of novel Enterococcus faecium and Leuconostoc mesenteroides from Tunisian freshwater fishes

Novel lactic acid bacteria isolated from different organs of freshwater fish were examined for their potential application as probiotics in raw and processed foods. Four isolates of Enterococcus faecium and Leuconostoc mesenteroides were identified at the molecular level by 16S rRNA sequencing and random amplification of polymorphic DNA - polymerase chain reaction, and their antimicrobial activity against a panel of pathogens and food-poisoning bacteria was investigated. The whole bacteriocins of the 4 isolates were characterized by enterobacterial repetitive intergenic consensus sequences in PCR. The isolates exhibited high inhibitory activities against food-borne pathogens and spoilage microbial species and have significant probiotic profiles, since they survived at pH 3.0 and in the presence of bile salts, pancreatin, and pepsin, without any detectable hemolytic activity. Further, moderate heat resistance, adhesion ability to steel surfaces, and sensitivity to clinically relevant antimicrobial agents were revealed for all the isolates. These results highlight the specific probiotic properties of the strains and give evidence for potential application in minimally processed foods subjected to moderate heat processing.

Probiotics against neoplastic transformation of gastric mucosa: Effects on cell proliferation and polyamine metabolism

Gastric cancer is still the second leading cause of cancer death worldwide, accounting for about 10% of newly diagnosed neoplasms. In the last decades, an emerging role has been attributed to the relations between the intestinal microbiota and the onset of both gastrointestinal and non-gastrointestinal neoplasms. Thus, exogenous microbial administration of peculiar bacterial strains (probiotics) has been suggested as having a profound influence on multiple processes associated with a change in cancer risk. The internationally accepted definition of probiotics is live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The possible effects on the gastrointestinal tract following probiotic administration have been investigated in vitro and in animal models, as well as in healthy volunteers and in patients suffering from different human gastrointestinal diseases. Although several evidences are available on the use of probiotics against the carcinogen Helicobacter pylori, little is still known about the potential cross-interactions among probiotics, the composition and quality of intestinal flora and the neoplastic transformation of gastric mucosa. In this connection, a significant role in cell proliferation is played by polyamines (putrescine, spermidine, and spermine). These small amines are required in both pre-neoplastic and neoplastic tissue to sustain the cell growth and the evidences here provided suggest that probiotics may act as antineoplastic agents in the stomach by affecting also the polyamine content and functions. This review will summarize data on the most widely recognized effects of probiotics against neoplastic transformation of gastric mucosa and in particular on their ability in modulating cell proliferation, paying attention to the polyamine metabolism.

Isolation, identification and characterisation of three novel probiotic strains (Lactobacillus paracasei CNCM I-4034, Bifidobacterium breve CNCM I-4035 and Lactobacillus rhamnosus CNCM I-4036) from the faeces of exclusively breast-fed infants

The aim of the present study was to isolate, identify and characterise novel strains of lactic acid bacteria and bifidobacteria with probiotic properties from the faeces of exclusively breast-fed infants. Of the 4680 isolated colonies, 758 exhibited resistance to low pH and tolerance to high concentrations of bile salts; of these, only forty-two exhibited a strong ability to adhere to enterocytes in vitro. The identities of the isolates were confirmed by 16S ribosomal RNA (rRNA) sequencing, which permitted the grouping of the forty-two bacteria into three different strains that showed more than 99 % sequence identity with Lactobacillus paracasei, Lactobacillus rhamnosus and Bifidobacterium breve, respectively. The strain identification was confirmed by sequencing the 16S-23S rRNA intergenic spacer regions. Strains were assayed for enzymatic activity and carbohydrate utilisation, and they were deposited in the Collection Nationale de Cultures de Microorganismes (CNCM) of the Institute Pasteur and named L. paracasei CNCM I-4034, B. breve CNCM I-4035 and L. rhamnosus CNCM I-4036. The strains were susceptible to antibiotics and did not produce undesirable metabolites, and their safety was assessed by acute ingestion in immunocompetent and immunosuppressed BALB/c mouse models. The three novel strains inhibited in vitro the meningitis aetiological agent Listeria monocytogenes and human rotavirus infections. B. breve CNCM I-4035 led to a higher IgA concentration in faeces and plasma of mice. Overall, these results suggest that L. paracasei CNCM I-4034, B. breve CNCM I-4035 and L. rhamnosus CNCM I-4036 should be considered as probiotic strains, and their human health benefits should be further evaluated.

Reduction of tyramine by addition of Schizandra chinensis baillon in Cheonggukjang

This study was performed to examine the microorganisms responsible for the high tyramine content of Cheonggukjang, a traditional Korean fermented soy food, and to establish a technology for controlling the growth of these microorganisms. The tyramine content in 13 collected Cheonggukjang samples averaged 604.9 mg/kg. Since the tyramine content measured from most samples was sufficient to cause harm to the human body, it is necessary to control its production in food. Enterococci were confirmed to be the bacterial species producing most of the tyramine through the microbial examination and were present in high numbers from not detected (<10(1)) to 7.0 × 10(10) colony-forming units (CFU)/g. To control the growth of enterococci, various plant extracts with antimicrobial activity, common salts, and variable temperature conditions were tested. It was found that 4 samples among the 159 plant extracts had a strong antimicrobial activity in Cheonggukjang, especially against Enterococcus faecium, showing viable cell counts of <10(1)-10(3) CFU/g after 24 h of ripening, which were significantly lower values compared to the control (10(9)-10(11) CFU/g). The Cheonggukjang with the addition of the four plant extracts showed ∼83%-95% lower concentrations of tyramine compared to the control. Cheonggukjang prepared with the Schizandra chinensis Baillon extract had the lowest tyramine content without sacrificing the sensory quality. Not only was the bacterial species of E. faecium reduced more remarkably, by up to 10(3) CFU/g compared to the 10(9)-10(11) CFU/g shown in the control, but it also decreased the tyramine content by up to 91%.

Oral administration of a combination of select lactic acid bacteria strains to reduce the Salmonella invasion and inflammation of broiler chicks

One-day-old chicks are susceptible to infection by strains of Salmonella enterica subspecies. Because multistrain probiotics are suggested to be more effective than monostrain probiotics due to the additive and synergistic effects, in this study, we prepared a multistrain formula A (MFA) consisting of 4 lactic acid bacteria (LAB) strains selected by enhancing the TNF-α production for mouse macrophage 264.7 cells. The antagonistic effect of this MFA against the cecal colonization, viscera invasiveness, as well as the inflammation of 1-d-old chicks challenged with Salmonella Typhimurium were then assayed. One-day-old chicks were fed with MFA from d 1 to d 3, and on d 4, chicks were challenged with Salmonella Typhimurium (200 μL, 10(6) cfu/mL). The livers, spleens, and cecal tonsils of chicks were then removed on d 3 and 6 postinfection. Compared with the multistrain formula B (MFB) which consisted of LAB strains selected at random, the efficacy of MFA to reduce the Salmonella counts recovered from the cecal tonsils, spleens, and livers of chicks were significantly higher. Moreover, when the levels of proinflammatory cytokines, such as IL-1β, IL-6, interferon (IFN)-γ, and anti-inflmmatory cytokine, that is, IL-10, in cecal tonsils were measured by reverse-transcription real-time quantitative PCR; it was found that chicks fed with MFA for 3 d had lower levels of IL-1β, IL-6, IFN-γ and a higher level of IL-10 in the cecal tonsils of chicks as compared with those of the chicks fed with MFB or without LAB. These results suggest that multistrain probiotics consisting of LAB strains selected by immunomodulatory activity and adherence are more effective than those consisting of strains selected at random in antagonistic effect against Salmonella colonization, invasion, and the induced inflammation.

Antagonistic activities of lactobacilli against Helicobacter pylori growth and infection in human gastric epithelial cells

Lactobacilli have positive effects on bowel microflora and health in humans and animals. In this study, the antagonistic activities of Lactobacillus gasseri Chen, and L. plantarum 18 were assessed by agar plate diffusion assay and tests that determined the growth and urease activity of Helicobacter pylori cocultured with lactobacilli and the adherence of H. pylori to human gastric epithelial cells in the presence of lactobacilli. The results showed that the 2 Lactobacillus strains had significant anti-H.pylori activity, and this activity may be contributed by the cell-free supernatants (CFS) of lactobacilli and live Lactobacillus strains in vitro. The antagonistic activity of the CFS against H. pylori depended on the pH and the presence of metabolites, such as organic acids and proteases. Our results also indicated that 2 Lactobacillus strains could inhibit H. pylori adherence human gastric epithelial cells.

PRACTICAL APPLICATION

Helicobacter pylori causes chronic gastritis, peptic ulcer disease, and gastric cancer, and it infects about 50% of the world's population. Lactobacilli have been reported to have an inhibitory effect on H. pylori and can be used as probiotic to manufacture dairy products preventing H. pylori infection.

The relative efficacy of different strain combinations of lactic acid bacteria in the reduction of populations of Salmonella enterica Typhimurium in the livers and spleens of mice

Multispecies probiotics have been reported to be more effective than monostrain probiotics in health promoting for the host. In this study, 12 lactic acid bacteria (LAB) strains were selected based on the level of induction of tumor necrosis factor (TNF)-α in RAW 264.7 macrophage cells. Their adherence to Caco-2 cells and inhibitory effects on Salmonella invasion of Caco-2 cells were compared. Strains with different probiotic properties were then combined and BALB/c mice were fed with LAB strains for 63 days; then the mice were challenged with Salmonella on day 64. For Salmonella-unchallenged mice that received a multistrain combination of LAB strains that have greater TNF-α production in macrophages, greater adherence and inhibit Salmonella invasion of Caco-2 cells to a greater extent, their peritoneal macrophages had greater phagocytic activity. For Salmonella-challenged mice, a significant reduction of Salmonella cells in the livers and spleens of the mice was observed 8 days post challenge. The addition of 12% skim milk powder together with LAB strain combinations significantly enhanced the reduction of Salmonella cells in the mice livers and spleens. In conclusion, we have shown that LAB strain combinations with particular probiotic properties when fed to mice can inhibit Salmonella invasion of the liver and spleen.

Novel probiotic Bifidobacterium bifidum CECT 7366 strain active against the pathogenic bacterium Helicobacter pylori

Helicobacter pylori is considered one of the major risk factors underlying the development of gastritis and gastric and duodenal ulcers. Moreover, 50% of the population carries this bacterium, and consequently, when it is detected, eradication of H. pylori is strongly recommended. Regarding the use of probiotics as functional agents, several studies have shown that there is a direct relationship between the addition of certain probiotic bacteria and in vitro inhibition of H. pylori; however, in vivo studies showing bifidobacterial activity against H. pylori remain scarce. In this study, a Bifidobacterium bifidum strain which proved active in vitro against H. pylori has been isolated, with inhibition levels reaching 81.94% in the case of the supernatant and even 94.77% inhibition for supernatant purified by cationic exchange followed by an inverse phase. In vivo studies using a BALB/c mouse model have proved that this strain partially relieves damage to gastric tissues caused by the pathogen and also decreases the H. pylori pathogenicity ratio. This novel strain fulfills the main properties required of a probiotic (resistance to gastrointestinal juices, biliary salts, NaCl, and low pH; adhesion to intestinal mucus; and sensitivity to antibiotics). Furthermore, the absence of undesirable metabolites has been demonstrated, and its food safety status has been confirmed by acute ingestion studies in mice. In summary, the results presented here demonstrate that Bifidobacterium bifidum CECT 7366 can be considered a probiotic able to inhibit H. pylori both in vitro and in vivo.

Antimicrobial activity of enterocins from Enterococcus faecalis SL-5 against Propionibacterium acnes, the causative agent in acne vulgaris, and its therapeutic effect

A lactic acid bacterial strain was isolated from human fecal specimen and identified as Enterococcus faecalis SL-5. The isolated strain showed antimicrobial activity against Gram-positive pathogens assayed, especially the highest activity against Propionibacterium acnes. The antimicrobial substance was purified and verified as a bacteriocin (named ESL5) of E. faecalis SL-5 by activity-staining using P. acnes as an indicator. N-terminal sequence of ESL5 was determined (MGAIAKLVAK) and sequence analysis revealed that it is almost identical to the some of enterocins including L50A/B of E. faecium L50 and MR10A/B of E. faecalis MRR 10-3. From the sequencing data of L50A/B structural genes, the nucleotide sequence showed 100% identity with that of the MR10A/B structural genes, implying that ESL5 is an equivalent of enterocin MR10. Meanwhile, we also tested the therapeutic effect of anti-P. acnes activity in patients with mild to moderate acne because of its pathogenic role to acne vulgaris. For this purpose, a concentrated powder of CBT SL-5 was prepared using cell-free culture supernatant (CFCS) of E. faecalis SL-5 and included in a lotion for application in the patients. The study showed that CBT SL-5 lotion significantly reduced the inflammatory lesions like pustules compared to the placebo lotion. Therefore our results indicate that the anti-P. acnes activity produced by E. faecalis SL-5 has potential role to the treatment of acne as an alternative to topical antibiotics.

Effects of multispecies probiotic combination on helicobacter pylori infection in vitro

Probiotic bacteria alleviate many gastrointestinal symptoms, but the current trend of combining bacteria for additional benefit may make their effects more complex. We characterize four probiotics and their combination in terms of pathogen adhesion, barrier function, cell death, and inflammatory response in Helicobacter pylori-infected epithelial cells. H. pylori-infected Caco-2 cells were pretreated with Lactobacillus rhamnosus GG, Lactobacillus rhamnosus Lc705, Propionibacterium freudenreichii subsp. shermanii Js, Bifidobacterium breve Bb99, or all four organisms in combination. We evaluated the adhesion of H. pylori by in situ immunofluorescence; epithelial barrier function by measurement of transepithelial resistance; apoptosis by measurement of caspase 3 activation; cell membrane leakage by measurement of lactate dehydrogenase release; and inflammation by measurement of interleukin-8 (IL-8), IL-10, prostaglandin E(2) (PGE(2)), and leukotriene B(4) (LTB(4)) release. All probiotics inhibited H. pylori adhesion. L. rhamnosus GG, L. rhamnosus Lc705, P. freudenreichii subsp. shermanii Js, and the combination inhibited H. pylori-induced cell membrane leakage. L. rhamnosus GG, L. rhamnosus Lc705, and the combination initially improved epithelial barrier function but increased the H. pylori-induced barrier deterioration after incubation for 24 to 42 h. L. rhamnosus GG, L. rhamnosus Lc705, and P. freudenreichii subsp. shermanii Js inhibited H. pylori-induced IL-8 release, whereas L. rhamnosus GG, L. rhamnosus Lc705, and B. breve Bb99 suppressed PGE(2) release. None of these anti-inflammatory effects persisted when the probiotics were used in combination. The combination thus increased the levels of IL-8, PGE(2), and LTB(4) released from H. pylori-infected epithelial cells. The proinflammatory actions of the individual components dominated the anti-inflammatory effects when the probiotic bacteria were used in combination. Our results stress that the therapeutic response can be optimized if probiotic strains are characterized before they are used in combination.

Impact of selectedLactobacillusandBifidobacteriumspecies onListeria monocytogenesinfection and the mucosal immune response

The pathogenesis of Listeria monocytogenes depends on its ability to attach to and invade the gastrointestinal epithelium and subsequently withstand the host immune response. Despite a thorough understanding of the intracellular phase of infection, relatively little is known about how the pathogen behaves in the gastrointestinal tract and whether it is affected by the presence of host commensal microbiota. Lactobacillus and Bifidobacterium are two important genera of the human gut microbiota proposed to possess probiotic effects. Here we demonstrate that probiotic bacteria significantly inhibit subsequent listerial infection in an in vitro C2Bbe1 epithelial cell model. In the case of Lactobacilli, inhibition was due to a combination of acid production and secretion of an as yet unidentified protein. In the case of Bifidobacterium, inhibition was attributable to an extracellular proteinaceous secreted compound. In addition, we observed a significant reduction in interleukin-8 and an increase in IL-10 cytokines secreted from epithelial cells following probiotic pretreatment and subsequent infection with Listeria. A reduction in the infection of epithelial cells and an altered mucosal immune response suggests that probiotic bacteria could be of therapeutic benefit against listerial infection. This study infers a role for probiotic bacteria as an antagonist of Li. monocytogenes infection.

Basic Characteristics of Sporolactobacillus inulinus BCRC 14647 for Potential Probiotic Properties

The basic characteristics of the spore-forming lactic acid bacterium, Sporolactobacillus inulinus BCRC 14647, was evaluated in vitro for its potential probiotic properties. Assessments including acid and bile salt tolerance, adhesiveness, and antagonistic effects on pathogenic Salmonella enteritidis BCRC 10744, as well as inhibition factors of spent culture supernatant (SCS) and an invasion assay, were conducted using Lactobacillus acidophilus BCRC 10695 and two bifidobacteria (Bifidobacterium bifidum BCRC 14615 and B. longum BCRC 11847) as a reference. In the results, S. inulinus spores presented significantly higher survival rates than the vegetative cell form in acidic conditions as well as the reference bifidobacteria. However, L. acidophilus showed the highest viability among all tested strains. Similar results were found in the bile tolerance test. Compared with the reference strains, the vegetative cell form of S. inulinus possessed a proper adhesive characteristic (71.7 bacteria/field for S. inulinus and 91.3 and 45.7 bacteria/field for B. bifidum and B. longum, respectively). In the adhesion assay, both the spore form of S. inulinus (17.1 bacteria/field) and the negative control, L. bulgaricus BCRC 14009 (5.9 bacteria/field), displayed nonadhesive traits. The vegetative cells of S. inulinus and its SCS both dramatically decrease the adhesion of S. enteritidis to Caco-2 cells; meanwhile, the SCS of S. inulinus vegetative cells inhibited the growth of S. enteritidis in the inhibition zone test. The existing inhibition factor could be assumed to be lactic acid in the SCS. From the results of the invasion assay, S. inulinus showed high safety properties. In conclusion, based on these in vitro evaluations, results suggest that S. inulinus presents probiotic features of great potential in the vegetative cell form.

Viable counts, characteristic evaluation for commercial lactic acid bacteria products

Eight commercial lactic acid bacteria (LAB) products were assayed for their LAB cell counts, acid and bile tolerance, and adherence to human intestinal epithelium. Results showed that the viable cell densities in liquid products, such as fermented milk samples, were higher than those in the solid products. In two solid products, viable LAB counts were not found indicating the incorrect labeling on the package. With a simulated human gastrointestinal digestion system, LAB strains from different commercial products were found to have different acid and bile tolerance. Twenty five LAB isolates from five commercial products were assayed for their antagonistic activities against bacterial pathogens, such as Staphylococcus aureus, Escherichia coli including enterotoxigenic strain, and Salmonella typhimurium. The spent culture supernatant (SCS) from some LAB isolates significantly inhibited the growth of these indicator bacteria. Among these 25 isolates, only five from one commercial product exhibited weak adherence to the human intestinal epithelial cells (Int-407). The rest showed no adherence at all. In conclusion, only few commercial LAB products meet the basic requirements for probiotic functions.

Systematic review: are probiotics useful in controlling gastric colonization by Helicobacter pylori?

Helicobacter pylori is a highly prevalent pathogen considered as an aetiological factor for gastroduodenal ulcers, and a risk factor for gastric adenocarcinoma and lymphoma in humans. Most subjects colonized by this micro-organism are asymptomatic and remain untreated. In symptomatic patients, the antibiotic treatment has a high cost and is not 100% effective because of resistance to antibiotics and to moderate patient compliance. This review discusses the role of probiotics as alternative solutions to assist in the control of H. pylori colonization in at-risk populations. The evidence that some strains of Lactobacillus and Bifidobacterium are able to inhibit H. pylori growth through the release of bacteriocins or organic acids, and may also decrease its adhesion to epithelial cells, is reviewed. In addition, probiotics have a possible role in the stabilization of the gastric barrier function and the decrease of mucosal inflammation. Other aspects that are considered are the contribution of probiotics to the healing of the gastric mucosa linked to their antioxidant and anti-inflammatory properties. Clinical trials in colonized adults and children are reviewed, and suggest that probiotics do not eradicate H. pylori but maintain lower levels of this pathogen in the stomach; in combination with antibiotics, probiotics may increase eradication rate and/or decrease adverse effects. Papers suggesting similar effects on H. pylori by foodstuffs such as berry juice and some milk proteins are quoted. Regular intake of these and other dietary products might constitute a low-cost, large-scale alternative solution applicable for populations at-risk for H. pylori colonization.

In vitro inhibition ofHelicobacter pyloribyEnterococcus faeciumGM-1

A strain of Enterococcus faecium that exhibits antibacterial activity against Helicobacter pylori was isolated from the feces of newborn babies. This strain was selected for its ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions, such as acidic pH and high bile concentration. Biochemical tests and 16S rRNA sequencing specific for Enterococcus faecium GM-1 were used to identify the isolated bacterial strain. In vitro studies were used to investigate the inhibitory effects of E. faecium GM-1 on H. pylori. These results showed that the culture supernatant of E. faecium GM-1 significantly decreased the viability and urease activity of H. pylori. This inhibitory activity remained after adjustment of pH of culture supernatant to neutral. However, treatment with proteolytic enzymes reduced the anti-H. pylori activity of GM-1. Therefore, some substance(s) of E. faecium GM-1 other than pH and lactic acid might be associated with this inhibitory activity. Analysis by electron microscopy also demonstrated that the addition of GM-1 destroyed the cell structure of H. pylori. Additional studies suggested that the binding of H. pylori to human colonial cells decreased in the presence of GM-1.Key words: Enterococcus faecium, Helicobacter pylori, inhibition, human fecal strain, proteinaceous substance(s).

Toxicity evaluation for an Enterococcus faecium strain TM39 in vitro and in vivo

Previously, we have screened lactic acid bacteria (LAB) strains from infant feces and evaluated their functional properties. We found a strain of Enterococcus faecium termed as TM39 which is acid and bile tolerant, able to adhere to the intestinal epithelium and with antagonistic activity against Helicobacter pylori. In this study, we demonstrate that strain TM39 is not vancomycin resistant, not invasive to human gastric carcinoma cell line TSGH 9201 and human intestinal epithelial cell line Int-407 in vitro. In addition, we have conducted the in vivo study to evaluate the toxicity of this E. faecium strain TM39 in Wistar rats. For such study, cells of strain TM39 were daily oral administrated with dose of 1 x 10(12), 5 x 10(11) and 2 x 10(10) CFU/kg of body weight, respectively, to the rats for 28 consecutive days. There were no adverse effects on the general condition, behavior, growth, feed and water consumption, hematology, clinical chemistry values, organ weights and histopathologic analysis of the rats. Results of this study demonstrate that consumption of strain E. faecium TM39, even in large quantities, is not associated with any obvious signs of toxicity in Wistar rats.