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PubMed2003

Development of surrogate markers for oral immunisation against Candida albicans.

We have developed an oral vaccine using the blastococcoid form of Candida albicans with a murine model of oral candidiasis with infection-resistant (BALB/c) and infection-prone (DBA/2) mice. Previous studies had demonstrated that enhanced clearance was linked to increased production of both Th1 and Th2 cytokines (IFN-gamma and IL-4, respectively) in regional lymph nodes, and increased secretion of IFN-gamma and NO in saliva. Subsequent study using oral Lactobacillus acidophilus (LAVRI-A1) induced a local cytokine pattern and enhanced clearance of intra-oral C. albicans similar to that noted in animals given killed candida vaccine. Thus, the experiment was repeated with a 2 month gap between completion of a vaccine course and challenge with live C. albicans. Compared to control mice, those given the oral vaccine had a 4 log reduction in colonisation on day 2, associated with twice the levels of secretion of IFN-gamma and IL-4 from the regional node cells, five times the level of nitric oxide in saliva, and suppression of NO production with MMLA induced a 2 log increase in oral colonisation. Thus while both IFN-gamma and IL-4 appear to contribute to clearance of oral C. albicans, IL-4 appears to act through a paracrine enhancement of NO production. Studies in man are in progress to define similar surrogate markers of immune protection, prior to oral vaccine trial.

Administration, Oral↗
PubMed1971

Lactobacillus exonuclease mutants: selection of mutants with altered ability to utilize deoxyribonucleotides.

Lactobacillus acidophilus R-26, which requires preformed deoxyriboside for its growth, is able to grow in a basal medium supplemented with nitrophenyl esters of thymidine 3'- and 5'-phosphates. Mutants unable to grow on the thymidine phosphate esters were isolated and classified thus far into two classes. One class of mutants that are unable to grow on the diesters have modified exonucleases, their extracts being unable to hydrolyze the specific nitrophenyl ester on which the strain did not grow. It appears therefore, that the known 3'- and 5'-exonucleases specifically hydrolyzing these esters can be used for the support of growth. A second mutagenization treatment of one of the mutants gave rise to a new strain unable to use or hydrolyze either diester for growth, although it could still grow on several deoxyribodinucleotides. Another class of mutants does not grow on deoxyribooligonucleotides but grows on monodeoxyribo-nucleosides and -nucleotides. These mutants have normal levels of exonuclease activities, so it appears possible that they bear a mutation affecting permeability to diesters or to molecules larger than mononucleotides.

Culture Media↗
PubMed1998

Increase in milk yield of commercial dairy herds fed a microbial and enzyme supplement.

A microbial and enzyme supplement fed at 21.2 g/d per cow to 46 Virginia dairy herds increased the milk yield of 31 herds (17 significantly) and decreased the milk yield of 15 herds (7 significantly). Effects of season were important but consistent with overall results. Herds began receiving the supplement, which contained dried fermentation products of Aspergillus oryzae, Bacillus subtilis, Lactobacillus acidophilus, and yeast culture, midway between the first and second monthly Dairy Herd Improvement tests and continued on the supplement through the 3rd mo. Entry of herds was staggered over 8 mo to reduce the influence of season. The trial involved 3417 cows with 5 test mo between 60 and 365 d in milk. Milk yield during mo 3 averaged 0.64 kg/d per cow more (+0.73 kg/d for first lactation cows and +0.56 kg/d for later lactation cows) than the mean milk yield during mo 1 and 5. Herds completing the study before summer responded similarly to all other herds, which included herds that were fed the product during summer and those that finished the study during summer. Fat and protein yields and protein percentage differed little with or without the supplement. Fat percentage decreased (0.10%). Twenty-one herds that were fed a yeast product prior to and during the study responded similarly to the 17 herds that were not fed a yeast product.

Animals↗
PubMed1998

Study of the morphology of the cell walls of some strains of lactic acid bacteria and related species.

The objective of the present study was to find an explanation for the biological effect of the bacteria present in a biotherapeutic milk (Lactobacillus casei CRL 431 and Lactobacillus acidophilus CRL 730). The ability of bacterial cell walls to induce an immune response when introduced into an organism is well known. In this paper we specifically analyzed the morphology of these cell walls. Besides the two bacterial strains used in the fermented milk, two other lactic acid bacteria, belonging to another genus and unable to induce an immune system response, as well as a strain of Propionibacterium, of which the immune modulating capacity is known, were used in this work. We found a structural particularly in strains with immunostimulating capacity (L. casei CRL 431 and P. acidopropionici CRL 1198): molecules which protrude from the cell surface. In L. casei CRL 431 these molecules were identified as lectins because they are able to agglutinate yeast cells treated with glutaraldehyde and glycine. The structures protruding from P. acidipropionici CRL 1198 cells were teichoic acids. Teichoic acid and lectin-like structures can participate in adhesion to intestinal cells. The immunostimulation observed can be induced by the adhesion phenomenon.

Adjuvants, Immunologic↗
PubMed1999

Dietary calcium phosphate stimulates intestinal lactobacilli and decreases the severity of a salmonella infection in rats.

We have shown recently that dietary calcium phosphate (CaPi) has a trophic effect on the intestinal microflora and strongly protects against salmonella infection. It was speculated that precipitation by CaPi of intestinal surfactants, such as bile acids and fatty acids, reduced the cytotoxicity of intestinal contents and favored growth of the microflora. Because lactobacilli may have antagonistic activity against pathogens, the main purpose of the present study was to examine whether this CaPi-induced protection coincides with a reinforcement of the endogenous lactobacilli. In vitro, Salmonella enteritidis appeared to be insensitive to bile acids and fatty acids, whereas Lactobacillus acidophilus was killed by physiologically relevant concentrations of these surfactants. Additionally, after adaptation to a purified diet differing only in CaPi concentration (20 and 180 mmol CaHPO4. 2H2O/kg), rats (n = 8) were orally infected with S. enteritidis. Besides reducing the cytotoxicity and the concentration of bile acids and fatty acids of ileal contents and fecal water, CaPi notably changed the composition of ileal bile acids in a less cell-damaging direction. Significantly greater numbers of ileal and fecal lactobacilli were detected in noninfected, CaPi-supplemented rats. As judged by the lower urinary NOx excretion, which is a biomarker of intestinal bacterial translocation, dietary CaPi reduced the invasion of salmonella. Additionally, the colonization resistance was improved considering the reduction of excreted fecal salmonella. In accordance, fewer viable salmonella were detected in ileal contents and on the ileal mucosa in the CaPi group. In conclusion, reducing the intestinal surfactant concentration by dietary CaPi strengthens the endogenous lactobacilli and increases the resistance to salmonella.

Animals↗
PubMed1998

Antimutagenic properties of probiotic bacteria and of organic acids.

Antimutagenic activities of live and killed cells of 6 strains of Lactobacillus acidophilus and 9 strains of bifidobacteria and of organic acids usually produced by these probiotic bacteria were determined using 8 potent chemical mutagens and promutagens. The mutagens and promutagens used were N-methyl, N'-nitro, N-nitrosoguanidine; 2-nitroflourene; 4-nitro-O-phenylenediamine; 4-nitroquinoline-N-oxide; Aflatoxin-B; 2-amino-3-methyl-3H-imidazoquinoline; 2-amino-1-methyl-6-phenyl-imidazo (4,5-b) pyridine, and 2-amino-3-methyl-9H-pyrido (3,3-6) indole. The mutagenicity of these mutagens and antimutagenic activity of probiotic bacteria against the mutagens were determined according to the Ames TA-100 assay using a mutant of Salmonella typhimurium. Efficiency of bacterial cells in binding or inhibiting these mutagens was also investigated. Live cells of probiotic bacteria showed higher antimutagenic activity and their efficiency in inhibiting the mutagens was better than killed bacterial cells. Live bacterial cells bound or inhibited the mutagens permanently, whereas killed bacteria released mutagens upon extraction with dimethyl sulfoxide. Among the organic acids, butyric acid showed highest inhibition of mutagens followed by acetic acid. Lactic and pyruvic acids did not show appreciable levels of inhibition.

Bifidobacterium↗
PubMed2003

Application of ultrasound-assisted thermal processing for preservation and quality retention of liquid foods.

A continuously working pilot plant-scale prototype was used to evaluate the effects of continuous-flow ultrasound-temperature treatment for bacterial decontamination of model suspensions and various liquid food systems such as milk, fruit, and vegetable juices. Escherichia coli K12 DH 5 alpha and Lactobacillus acidophilus were used as test microorganisms. In addition, treated juices were investigated for damage caused by heat or ultrasound-induced degradation of sensory and nutritional properties after treatment and storage. Changes in color and destruction of heat-labile and slightly oxidizable L-ascorbic acid content were monitored as an index to measure processing effects. Results were assessed with respect to the total energy requirement and compared with those using a conventional, indirect heating method having similar processing conditions. For the bacteriological process evaluation, the temperature- and time-dependent process lethality was used as the basis; for the quality- and energy-related investigations, the degree of bacterial inactivation was used. At identical degrees of bacterial inactivation, the ultrasound-assisted thermal treatments required a lower processing temperature than treatment with conventional thermal processing. However, according to energy balances, the total energy consumption was not reduced compared to conventional heating. Indications for a positive influence on shelf life, with improvements in surface color stability (lightness) and L-ascorbic acid retention, were found among quality parameters of treated orange juice.

Beverages↗
PubMed2006

Probiotics and commensals reverse TNF-alpha- and IFN-gamma-induced dysfunction in human intestinal epithelial cells.

BACKGROUND & AIMS: Commensal bacteria are crucial for the development of the mucosal immune system. Probiotics are commensals with special characteristics and may protect mucosal surfaces against pathogens. Pathogens cause significant phenotypic alterations in infected epithelial cells, and probiotics reverse these deleterious responses. We hypothesized that probiotics and/or commensals may also reverse epithelial damage produced by cytokines. METHODS: Human intestinal epithelial cells were exposed basolaterally to interferon (IFN)-gamma (10(3) U/mL) or tumor necrosis factor (TNF)-alpha (10 ng/mL) for up to 48 hours and assessed for ion transport, transepithelial resistance (TER), and epithelial permeability in the presence or absence of probiotics (Streptococcus thermophilus [ST] and Lactobacillus acidophilus [LA]), or the commensal, Bacteroides thetaiotaomicron (BT). RESULTS: Agonist-stimulated chloride secretion was inhibited by IFN-gamma, an effect prevented by ST/LA or BT. The ability of ST/LA or BT to restore Cl(-) secretion was blocked by inhibitors of p38 MAPK, ERK1, 2, and PI3K. The cystic fibrosis transmembrane conductance regulator (CFTR) and the NKCC1 cotransporter were down-regulated by IFN-gamma, and ST/LA pretreatment reversed this effect. Both TNF-alpha and IFN-gamma significantly reduced TER and increased epithelial permeability, effects prevented by ST/LA or BT. A Janus kinase (JAK) inhibitor synergistically potentiated effects of ST/LA or BT on TER and permeability, but p38, ERK1, 2, or PI3K inhibition did not. Finally, only probiotic-treated epithelial cells exposed to cytokines showed reduced activation of SOCS3 and STAT1,3. CONCLUSIONS: Deleterious effects of TNF-alpha and IFN-gamma on epithelial function are prevented by probiotic, and to a lesser extent, commensal pretreatment. These data extend the spectrum of effects of such bacteria on intestinal epithelial function and may justify their use in inflammatory disorders.

Bacteroides↗
PubMed2005

Ernst Moro (1874-1951)--a great pediatric career started at the rise of university-based pediatric research but was curtailed in the shadows of Nazi laws.

Ernst Moro was born on December 8, 1874, in Ljubljana, the capital of Slovenia, then part of the Austro-Hungarian empire and attended university in Graz, Austria. Pediatrics, initially regarded as a part of internal medicine, was in its early days as an independent field at universities in German-speaking Europe. The first Chair of Pediatrics had been established in Vienna, Austria in 1884. Ten years later Germany was granted its first Chair in Berlin. Escherich, who held the first Chair of Pediatrics at Graz, was seen as one of the most respected pediatricians in Europe. Therefore, he was invited in 1904 to represent pediatrics together with the American Abraham Jacobi at the International World Congress on Science at the Saint Louis World Exposition in the United States. The high mortality of nearly 25% in infancy was seen as one of the main problems. Escherich's scientific work had established him as the leading bacteriologist. Moro's pediatric career started in Escherich's laboratory with experimental research on the physiology of digestion in infants. In 1900 he presented the first bacteriological characterisation of Lactobacillus acidophilus. In 1906 he received his venia legendi for his work on the bacterial flora in physiological and pathological conditions of the infantile intestine. In 1908 Moro won international reputation for his simple percutaneous skin test for tuberculosis, which was widely used in many countries as the "Moro test" at least until the 1960s. He described a carrot soup and other dietary prescriptions as helpful for diarrhoeal disease. In 1911 he became Head of the Children's Hospital at Heidelberg. In 1918 he described some features peculiar to the first 3 months; according to him this trimenon should be regarded as an own entity like the newborn period. The most famous part of the paper was the description of a milestone in the infant's neurological development, the Umklammerungsreflex (embracing reflex). In 1919 Moro was promoted from associate professor to the first 'Ordinarius', thus founding the first Chair of Pediatrics at Heidelberg and marking the beginning of a scientifically most fruitful period of international collaboration. However, as his wife was of Jewish origin, Moro slowly withdrew from hospital service starting in 1933. After early retirement in 1936, he worked as a pediatrician at home until 1948.

Germany↗
PubMed1991

Effect of lactic acid producing bacteria on the human intestinal microflora during ampicillin treatment.

20 healthy volunteers participated in a double blind study concerning the effect of lactic acid producing bacteria on the intestinal microflora during ampicillin treatment. 10 volunteers received 500 mg ampicillin tablets t.i.d. together with capsules containing lactic acid producing bacteria (Lactobacillus acidophilus and Bifidobacterium bifidum) for 7 days, and the other 10 volunteers were given 500 mg ampicillin tablets together with placebo capsules t.i.d. for 7 days. Both groups of volunteers continued the intake of the capsules t.i.d. for another 14 days after the ampicillin administration had been completed. The number of enterococci, streptococci and corynebacteria decreased during ampicillin administration but returned to normal levels after 14 days. Yeasts increased during the antibiotic treatment but returned to the same levels as before treatment within 14 days. Escherichia coli strains were suppressed in most volunteers during ampicillin administration. The numbers of anaerobic gram-positive cocci and rods decreased in most subjects during ampicillin treatment but were normalized within 2 weeks. Bacteroides strains were recovered in higher numbers in the lactic acid producing bacteria group compared to the placebo group. The volunteers receiving lactic acid producing bacteria were recolonized slightly faster than those having placebo. There were adverse effects observed in 3 subjects receiving ampicillin plus placebo. In the lactic acid producing bacteria group, one subject had diarrhoea on day 3 to on day 3 to day 7.

Adult↗
PubMed2005

Effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria in vitro.

BACKGROUND: Cecropin-XJ belongs to cecropin-B, which is the most potent antibacterial peptide found naturally. The aim of this study was to investigate the effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria. METHODS: Four oral cariogenic bacteria (Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscosus and Actinomyces naeslundii) were chosen for this experiment. The minimal inhibitory concentrations (MICs) and reductive percent of bacterial growth were used to assay the antibacterial activity of cecropin-XJ. Mammalian cytotoxicity of cecropin-XJ was tested with human periodontal membrane fibroblasts by tetrazolium (MTT) colorimetric assay. The bacterial morphological changes induced by cecropin-XJ were examined on scanning electron microscope (SEM). The influence of cecropin-XJ on bacterial adhesion to saliva-coated hydroxyapatite (S-HA) was measured by scintillation counting. RESULTS: The MICs of cecropin-XJ for inhibition of the growth of four bacteria ranged from 4.0 to 42.8 micromol/L with the highest susceptible to A. naeslundii and the lowest susceptible to L. acidophilus. At pH 6.8, 5.5 and 8.2, 1/2 MIC of cecropin-XJ reduced the number of viable bacteria by 40.9%, 67.8% and 32.8% for S. mutans and by 28.1%, 57.2% and 37.9% for L. acidophilus. The activities against S. mutans and L. acidophilus increased at pH 5.5 compared with pH 6.8 (P < 0.01, respectively). In present of 50% saliva, 1/2 MIC of the peptide decreased the direct count of viable cells by 29.2% and 14.4% for S. mutans and L. acidophilus, respectively (P < 0.01 and P > 0.05, respectively), whereas almost no reduction counts were detected in the presence of 20% serum for both bacteria (P > 0.05, respectively). Mammalian cytotoxicity of cecropin-XJ from 1.0 to 100 micromol/L exhibited no cytotoxicity against human periodontal membrane fibroblasts (P > 0.05). Bacterial morphological changes induced by MIC of cecropin-XJ examined on SEM showed cell surface disruption. Furthermore, the ability of A. naeslundii adhesion to S-HA decreased significantly with MIC of cecropin-XJ for 10 and 20 minutes (P = 0.001 and 0.000, respectively), and S. mutans, A. viscosus to S-HA decreased significantly with MIC of cecropin-XJ for 20 minutes (P = 0.000, respectively). CONCLUSIONS: Cecropin-XJ exhibited bactericidal action against cariogenic pathogens, and the antibacterial activity enhanced in the acid environment. The results also demonstrate that cecropin-XJ prevents S. mutans and actinomyces adsorption to S-HA. These findings suggest that Cecropin-XJ may have potential to prevent caries.

Actinomyces viscosus↗
PubMed2006

Mutagenicity and antimutagenic effect of soymilk fermented with lactic acid bacteria and bifidobacteria.

In this study, soymilk was first fermented with lactic acid bacteria (Streptococcus thermophilus, Lactobacillus acidophilus) and bifidobacteria (Bifidobacterium infantis, Bifidobacterium longum) both individually and simultaneously. Mutagenicity and the suppression of fermented soymilk against the mutagenesis induced by 4-nitroquinoline-N-oxide (4-NQO), a direct-acting mutagen, and 3,2'-dimethyl-4-amino-biphenyl (DMAB), an indirect-acting mutagen, on Salmonella typhimurium TA 100, was then investigated. It was found that the fermented soymilk shows no mutagenic activity on Sal. typhimurium TA 100. Fermentation, in general, significantly (p<0.05) enhanced the antimutagenicity of soymilk. The levels of increased antimutagenicity of fermented soymilk varied with the starter organism and the type of mutagen tested. Although unfermented soymilk exerted lower antimutagenic activity against DMAB than 4-NQO, the fermented soymilk, generally, showed a higher antimutagenic activity against DMAB than 4-NQO. Among the various fermented soymilk tested, soymilk fermented with both Str. themophilus and B. infantis simultaneously exhibited the highest antimutagenicity of 85.07% and 85.78%, respectively, against 4-NQO and DMAB Further investigation on this fermented soymilk revealed that both the antimutagenic factors formed during fermentation and the cells of the starter organisms contributed to the increased antimutagenic activity against DMAB, while the former led to the increased activity against 4-NQO.

4-Nitroquinoline-1-oxide↗
PubMed1990

Influence of whey and probiotic-supplemented withdrawal feed on the retention of Salmonella intubated into market age broilers.

Broilers (6 wk of age) were crop-intubated with a nalidixic acid-resistant strain of Salmonella typhimurium and given four withdrawal feeds: 1) control feed (corn and soybean meal base, 18% CP and 3,200 kcal ME/kg); 2) control plus 5% whey (61% lactose); 3) control plus probiotic (6.8 x 10(6) cfu of Bifidobacterium pseudolongum, Bifidobacterium thermophilium, and Lactobacillus acidophilus); and 4) control plus 5% whey plus probiotic. In Experiment 1, male broilers received 9.8 x 10(7) cfu of S. typhimurium per bird midway through a 20-h fast. The withdrawal feeds were continuously offered through a subsequent period of 6 to 7 days. Live performance of broilers during this time was similar among treatments. Ceca from birds consuming whey were significantly (P less than .05) increased in weight and distended with gas. Recovery of S. typhimurium from the ceca was low with all treatments, and the effects of whey or probiotic at reducing the organism could not be determined. In Experiment 2, female broilers received the same four experimental feeds for 48 h. Salmonella typhimurium was intubated 24 h after feed access (1.2 x 10(7) cfu per bird). Again, no differences (P greater than .05) in performance occurred, but the inclusion of whey led to increased cecal weight and size (P less than .05). Large numbers of S. typhimurium were recovered from the ceca 24 h after intubation, but the levels were similar among treatments. Whey and probiotic in the withdrawal feed did not appear to affect the Salmonella level in ceca when the organism was consumed prior to marketing.

Animal Feed↗
PubMed2004

Effects of ingesting Lactobacillus- and Bifidobacterium-containing yogurt in subjects with colonized Helicobacter pylori.

BACKGROUND: Evidence suggests that ingesting lactic acid bacteria exerts a suppressive effect on Helicobacter pylori infection in both animals and humans. Supplementing with Lactobacillus- and Bifidobacterium-containing yogurt (AB-yogurt) was shown to improve the rates of eradication of H. pylori in humans. OBJECTIVE: We administered AB-yogurt to subjects with asymptomatic H. pylori to test whether the yogurt could inhibit H. pylori growth. DESIGN: The in vitro inhibition of H. pylori growth was determined by inoculating Lactobacillus acidophilus La5 or Bifidobacterium lactis Bb12 on plates that were inoculated with H. pylori. Assessment of the viability of H. pylori was performed by the mixed culture method with La5 or Bb12. In an intervention study, 59 adult volunteers infected with H. pylori were given AB-yogurt (10(7) colony-forming units of both La5 and Bb12/mL) twice daily after a meal for 6 wk. Eleven subjects positive for H. pylori infection were treated with milk placebo as control subjects. H. pylori bacterial loads were determined with use of the (13)C-urea breath test, which was performed before and 4 and 8 wk after the start of AB-yogurt supplementation. RESULTS: Bb12 exerted an in vitro inhibitory effect against H. pylori, whereas La5 did not show an effect. Administration of AB-yogurt decreased the urease activity of H. pylori after 6 wk of therapy (P < 0.0001). CONCLUSION: Regular intake of yogurt containing Bb12 and La5 effectively suppressed H. pylori infection in humans.

Adult↗
PubMed1997

Influence of carcinogen binding by lactic acid-producing bacteria on tissue distribution and in vivo mutagenicity of dietary carcinogens.

The aims of this investigation were to determine whether viable cultures of lactic acid-producing organisms (LAB) can bind dietary carcinogens and to assess the consequences of binding for the absorption from the gut, distribution in the body and in vivo genotoxicity of ingested carcinogens. The carcinogens used in this study were ones known to be present in the human diet, namely benzo[a]pyrene (B(a)P, aflatoxin B1 (AFB1) and the cooked food carcinogens 2-amino-3-methyl-3H-imidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 5-phenyl-2-amino-1-methylimidazo [4,5-f]pyridine (PhIP) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2). They represent a range of structural types so that the specificity of any binding effects could be addressed. Of the carcinogens tested, B(a)P and Trp-P-2 were bound most effectively by the two LAB strains Bifidobacterium longum and Lactobacillus acidophilus. AFB1 was poorly bound, while MeIQx, MeIQ, PhIP and IQ were bound to an intermediate degree. The extent of the binding of the heterocyclic amine carcinogens was dependent on the pH conditions during incubation and this effect was more apparent with B. longum than with L. acidophilus. Using the host-mediated assay (HMA), an in vivo bacterial mutation assay, it was demonstrated that the administration of bacterial cell suspensions of B. longum and L. acidophilus did not lead to a reduction in induced mutagenicity by MeIQ, MeIQx or Trp-P-2, detectable in the liver of treated mice compared with controls. The lack of a protective effect could not be attributed to a short period of contact between bacterial cells and mutagens, since similar results were obtained after preincubating bacteria and mutagens together at pH 5 for 50-60 min, to maximize the binding, before gavaging the mice. Lack of activity of B(a)P in the HMA prevented the determination of the effect of LAB on genotoxicity of the polycyclic aromatic hydrocarbon. However, it is clear from the radiolabel distribution study that the amount of the carcinogen entering the blood was not significantly reduced by B. longum administration. In addition, the amount of radiolabelled B(a)P that reached the target organs (liver, lungs and heart) was also not affected by the LAB administration. A similar lack of inhibitory effect of B. longum on blood concentration and accumulation in the liver of Trp-P-2 was apparent. The results of the present study suggest that although LAB may bind carcinogens in vitro, this does not lead to major changes in absorption and distribution of carcinogens in the body, or in their genotoxic activity in the liver.

Animals↗
PubMed2003

Live probiotics protect intestinal epithelial cells from the effects of infection with enteroinvasive Escherichia coli (EIEC).

BACKGROUND: The colonic epithelium maintains a life long reciprocally beneficial interaction with the colonic microbiota. Disruption is associated with mucosal injury. AIMS: We hypothesised that probiotics may limit epithelial damage induced by enteroinvasive pathogens, and promote restitution. METHODS: Human intestinal epithelial cell lines (HT29/cl.19A and Caco-2) were exposed to enteroinvasive Escherichia coli (EIEC 029:NM), and/or probiotics (Streptococcus thermophilus (ST), ATCC19258, and Lactobacillus acidophilus (LA), ATCC4356). Infected cells and controls were assessed for transepithelial resistance, chloride secretory responses, alterations in cytoskeletal and tight junctional proteins, and responses to epidermal growth factor (EGF) stimulation. RESULTS: Exposure of cell monolayers to live ST/LA, but not to heat inactivated ST/LA, significantly limited adhesion, invasion, and physiological dysfunction induced by EIEC. Antibiotic killed ST/LA reduced adhesion somewhat but were less effective in limiting the consequences of EIEC invasion of cell monolayers. Furthermore, live ST/LA alone increased transepithelial resistance, contrasting markedly with the fall in resistance evoked by EIEC infection, which could also be blocked by live ST/LA. The effect of ST/LA on resistance was accompanied by maintenance (actin, ZO-1) or enhancement (actinin, occludin) of cytoskeletal and tight junctional protein phosphorylation. ST/LA had no effect on chloride secretion by themselves but reversed the increase in basal secretion evoked by EIEC. EIEC also reduced the ability of EGF to activate its receptor, which was reversed by ST/LA. CONCLUSIONS: Live ST/LA interact with intestinal epithelial cells to protect them from the deleterious effect of EIEC via mechanisms that include, but are not limited to, interference with pathogen adhesion and invasion. Probiotics likely also enhance the barrier function of naïve epithelial cells not exposed to any pathogen.

Cell Adhesion↗
PubMed1999

Modulation of nonspecific mechanisms of defense by lactic acid bacteria: effective dose.

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk. The first two groups received a freshly prepared product fermented by Streptococcus thermophilus (group A) alone or S. thermophilus and 10(7) cfu/ml L. johnsonii La1 (group B). Group C received a product stored for a period of 21 to 28 d and that contained S. thermophilus and 10(6) cfu/ml of L. johnsonii La1. Ingestion of L. johnsonii La1 did not significantly increase fecal lactobacilli counts. However, L. johnsonii La1 was able to survive intestinal transit and was only recovered from the feces of the volunteers of groups B and C. The fermented base alone showed a weak effect on respiratory burst but not on phagocytic activity. However, the product containing 10(7) cfu/ml L. johnsonii La1 significantly enhanced both functions. The product containing 10(6) cfu/ml of L. johnsonii La1 had no significant effect on either function. These results suggest that fecal persistence may not necessarily reflect in vivo colonization and may not be a prerequisite for all forms of immune reactivity.

Adult↗
PubMed2002

Effects of lactic acid bacteria on the uptake and distribution of the food mutagen Trp-P-2 in mice.

BACKGROUND: Lactic acid bacteria have been reported to have antimutagenic and anticarcinogenic properties in vivo and in vitro. Lactobacillus acidophilus and Bifidobacterium longum have earlier been shown to bind the food mutagen Trp-P-2 in vitro. METHODS: The influence of oral supplementation with L. acidophilus NCFB 1748 and B. longum BB 536 on the uptake and distribution of 14C-labelled Trp-P-2 in several mouse tissues was quantified by liquid scintillation measurements and examined by tape section autoradiography (gives an unbiased qualitative registration of differences in overall tissue distribution) in the present investigation. Furthermore, the effect of 13-naphthoflavone (BNF), a cytochrome P4501A (CYP1A)-inducing agent, on the distribution of 14C-labelled Trp-P-2 was examined. RESULTS: After oral (6 mg/kg; 5 microCi) or iv (1.2 mg/kg; 1 microCi) administration of 14C-labelled Trp-P-2, high levels of radioactivity were observed in the bile, urine and contents of the gastrointestinal tract. Lower levels were present in the liver, lung, kidney, intestines, brown fat, submaxillary salivary gland and thymus. In mice supplemented with lactic acid bacteria there was a significantly decreased level (29%-73%) of radioactivity in the lung, thymus, liver, kidney, submaxillary salivary gland and small intestine as compared with controls. In mice pretreated with BNF, a low but distinct localization of radioactivity in the lung was observed, whereas no similar localization occurred in controls. CONCLUSIONS: The results suggest that (i) there is a decreased bioavailability of the Trp-P-2 in the majority of the tissues examined in bacteria supplemented mice and (ii) there is a low but distinct CYP1A-dependent activation of Trp-P-2 in the lung of BNF-treated mice.

Animals↗