PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Lactobacillus”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources

Influence of synbiotic containing Lactobacillus acidophilus La5, Bifidobacterium lactis Bb 12, Streptococcus thermophilus, Lactobacillus bulgaricus and oligofructose on gut barrier function and sepsis in critically ill patients: a randomised controlled trial.

BACKGROUND & AIMS: Infective complications are a common cause of mortality and morbidity in critically ill patients. Many factors affect sepsis, one of which is gut barrier function. The aim of this study was to determine whether the oral administration of a synbiotic preparation could alter gut barrier function in critically ill patients and thus reduce sepsis. METHODS: A total of 90 patients admitted to an intensive care unit (ICU) were randomised to receive either synbiotic or placebo preparations (45 into each group). The synbiotic preparation consisted of Lactobacillus acidophilus La5, Bifidobacterium lactis Bb 12, Streptococcus thermophilus and Lactobacillus bulgaricus (probiotics) with oligofructose (prebiotic). Gut barrier function was assessed by measurement of intestinal permeability (lactulose/rhamnose test) and culture of nasogastric aspirate on days 1 and 8. All septic complications and mortality were recorded. RESULTS: There were no differences between the groups in terms of age, sex, APACHE II or POSSUM scores. After 1 week of therapy, patients in the synbiotic group had a significantly lower incidence of potentially pathogenic bacteria (43% versus 75%, P = 0.05) and multiple organisms (39% versus 75%, P = 0.01) in their nasogastric aspirates than controls. There were no significant differences between the groups in terms of intestinal permeability, septic complications or mortality. CONCLUSIONS: The administration of synbiotic in critically ill patients favourably altered the microbial composition of the upper gastrointestinal tract but had no effect on intestinal permeability and was not associated with measurable clinical benefit.

Aged↗

Immune enhancing effects of Lactobacillus acidophilus LAFTI L10 and Lactobacillus paracasei LAFTI L26 in mice.

The immune enhancing properties of Lactobacillus acidophilus LAFTI L10 and Lactobacillus paracasei LAFTI L26 in mice were investigated. Each mouse (BALB/c) was orally fed with cultures of either L. acidophilus or L. paracasei at 10(8) CFU/50 mul per day for 14 days. The effect of these strains on immunoglobulin A, interleukin-10 and interferon gamma producing cells in the gut immune system was determined by immunofluorescence assays. Systemic immune responses were analysed in mice serum upon euthanising after a 14-day feeding trial to estimate cytokines such as IL-10 and IFN-gamma by enzyme-linked immunosorbent assays. L. acidophilus and L. paracasei strains demonstrated an increase in the number of IgA producing cells, IL-10 and IFN-gamma cytokine producing cells in the small intestine. In the systemic immune response, mice fed with L. acidophilus or L. paracasei also enhanced the secretion of anti-inflammatory cytokine (IL-10) and pro-inflammatory cytokine (IFN-gamma). The results of this study suggest that L. acidophilus and L. paracasei were able to enhance specific gut and systemic immune responses in mice.

Animals↗

Potential probiotic lactic acid bacteria Lactobacillus rhamnosus (HN001), Lactobacillus acidophilus (HN017) and Bifidobacterium lactis (HN019) do not degrade gastric mucin in vitro.

The mucus layer (mucin) coating the surface of the gastrointestinal tract (GIT) plays an important role in the mucosal barrier system. Any damage or disturbance of this mucin layer will compromise the host's mucosal defence function. In the present study, the ability of three potential probiotic lactic acid bacteria (LAB) strains (Lactobacillus rhamnosus HN001, Lactobacillus acidophilus HN017, Bifidobacterium lactis HN019) to degrade mucin in vitro was evaluated, in order to assess their potential pathogenicity and local toxicity. The LAB strains were incubated in medium containing hog gastric mucin (HGM, 0.3%) at 37 degrees C for 48 h, following which any decrease in carbohydrate and protein concentration in the ethanol-precipitated portion of the culture medium was determined, using phenol-sulphuric acid and bicinchonic acid (BCA) protein assays, respectively. The change in molecular weight of mucin glycoproteins, following incubation with the test strains, was monitored by SDS-polyacrylamide gel electrophoresis (SDS-PAGE). In order to expose any ability of the test strains to degrade mucin visually and more directly, the test strains were also cultured on agarose containing 0.3% HGM and incubated anaerobically for 72 h at 37 degrees C. No significant change in the carbohydrate or protein concentration in mucin substrates was found following incubation with the test strains. No mucin fragments were derived from the mucin suspension incubated with test strains, and no mucinolysis zone was identified on agarose. These results demonstrate that the potential probiotic LAB strains tested here were unable to degrade gastrointestinal mucin in vitro, which suggests that these novel probiotic candidates are likely to be non-invasive and non-toxic at the mucosal interface.

Anaerobiosis↗

Genes encoding bile salt hydrolases and conjugated bile salt transporters in Lactobacillus johnsonii 100-100 and other Lactobacillus species.

Lactobacillus johnsonii strain 100-100 expresses two antigenically distinct conjugated bile salt hydrolases (BSH), alpha and beta, that combine to form native homo- and heterotrimers. This paper reports characterization of loci within the genome that encode this capacity. A locus that encodes BSH beta (cbsH beta), a partial (cbsT1) and a complete conjugated bile salt transporter (cbsT2) was identified previously. DNA sequence analysis at this locus was extended and revealed a complete ORF for cbsT1 and no other ORFs in tandem. The three genes, cbsT1, cbsT2 and cbsH beta, probably constitute an operon; a putative promoter was identified upstream of cbsT1. A second locus that expresses BSH activity in strain 100-100 was identified. Sequence analysis of the clone predicted a 978 nt ORF that did not share tandem organization with other ORFs, was similar in sequence to other BSH genes, and matched, in predicted protein sequence, the first 25 amino acids of BSH alpha. A phenotypic screen for BSH activity and a genetic screen for the cbsH beta locus were performed on 50 Lactobacillus isolates from humans or dairy products. Nearly all of the isolates that were positive for cbsH beta were from human sources. Variability in the BSH phenotype and cbsH beta genotype was identified in isolates of the same species. DNA sequence was obtained and analysed from the cbsH beta locus of one human isolate, L. acidophilus strain KS-13. This organism has cbsT1, cbsT2 and cbs beta genes that are 84, 87 and 85% identical in DNA sequence to those of strain 100-100. DNA sequence identity to strain 100-100 ends in regions flanking this locus. The findings of this study suggest that BSH genes have been acquired horizontally and that BSH activity is important at some level for lactobacilli to colonize the lower gastrointestinal tract.

Amidohydrolases↗

Drug resistance plasmids in Lactobacillus acidophilus and Lactobacillus reuteri.

Sixteen strains of Lactobacillus reuteri and 20 strains of Lactobacillus acidophilus were tested for resistance to 22 antibiotics by using commercially available sensitivity disks. Evidence suggesting linkage of these resistances to plasmids was obtained by "curing" experiments with acridine dyes and high growth temperatures. Examination of plasmid patterns of agarose gel electrophoresis provided further evidence of loss in plasmid DNA under curing conditions in some of the strains examined.

Anti-Bacterial Agents↗

Lipoteichoic acids from Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 antagonize the responsiveness of human intestinal epithelial HT29 cells to lipopolysaccharide and gram-negative bacteria.

Intestinal epithelial cells (IECs) respond to lipopolysaccharide (LPS) from gram-negative bacteria in the presence of the soluble form of CD14 (sCD14), a major endotoxin receptor. Since sCD14 is also known to interact with gram-positive bacteria and their components, we looked at whether sCD14 could mediate their effects on human IECs. To this end, we examined the production of proinflammatory cytokines following exposure of the IECs to specific gram-positive bacteria or their lipoteichoic acids (LTAs) in the absence and presence of human milk as a source of sCD14. In contrast to LPS from Escherichia coli or Salmonella enteritidis, neither the gram-positive bacteria Lactobacillus johnsonii strain La1 and Lactobacillus acidophilus strain La10 nor their LTAs stimulated IECs, even in the presence of sCD14. However, both LTAs inhibited the sCD14-mediated LPS responsiveness of IECs. We have previously hypothesized that sCD14 in human milk is a means by which the neonate gauges the bacterial load in the intestinal lumen and liberates protective proinflammatory cytokines from IECs. The present observations suggest that gram-positive organisms, via their LTAs, temper this response and prevent an exaggerated inflammatory response.

Chemokine CXCL5↗

Transmission of Lactobacillus jensenii and Lactobacillus acidophilus from mother to child at time of delivery.

The presence of Lactobacillus jensenii and Lactobacillus acidophilus has been studied in specimens from the rectum and vagina of the mother, from the mouth of the infant at the time of delivery, and from the mouth and rectum of infants six days of age. L. jensenii could be differentiated from other species of lactobacilli by the following combination of characteristics: production of only D-lactate, hydrolysis of arginine, and fermentation of cellobiose, galactose, and ribose, but not of lactose. L. jensenii and L. acidophilus were common inhabitants of the vagina. In spite of a contamination of the infant's mouth by L. jensenii and L. acidophilus during delivery, neither of these organisms became established in the mouth of the newborn infants.

Adult↗

Evaluation of media for selective enumeration of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and bifidobacteria.

Fifteen media were evaluated to determine their suitability for selective enumeration of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus acidophilus, and bifidobacteria using 5 to 6 strains of each of the four groups of organisms. Streptococcus thermophilus agar was found to be suitable for selective enumeration of S. thermophilus under aerobic incubation at 37 degrees C for 24 h. The MRS agar at pH 5.2 or reinforced clostridial agar at pH 5.3 could be used for the selective enumeration of L. delbrueckii ssp. bulgaricus when the incubation was carried out at 45 degrees C for > or = 72 h. However, the recovery of this organism was lower on MRS agar at pH 5.2 or reinforced clostridial agar at pH 5.3 than that obtained on MRS agar. The recovery of L. acidophilus and bifidobacteria on MRS agar and MRS-maltose agar was similar; MRS-maltose agar could be used to enumerate total counts of L. acidophilus and bifidobacteria. For selective enumeration of L. acidophilus, MRS-salicin agar or MRS-sorbitol agar could be used. For selective enumeration of bifidobacteria, MRS NNLP (nalidixic acid, neomycin sulfate, lithium chloride, and paromomycin sulfate) agar was suitable; however, determination of bifidobacteria by differential counts between L. acidophilus enumerated on MRS-salicin agar or MRS-sorbitol agar and the total counts of L. acidophilus and bifidobacteria obtained from MRS-maltose agar resulted in higher recovery of some strains of bifidobacteria. Other media that were evaluated in this study were not suitable for selective enumeration.

Bifidobacterium↗

Testing two Lactobacillus plantarum and Lactobacillus acidophilus strains for their suitability as a lipoid probiotic.

Two strains of lactobacilli (Lactobacillus acidophilus T-135 and Lactobacillus plantarum 4/97) were selected in order to study their inhibitory properties against frequent udder pathogens (Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Salmonella enteritidis and Bacillus pumilus), their production of organic acids as well as their ability to survive on the teat skin, the teat duct mucosa and in a lipoid emulsion. Both strains inhibited the tested pathogenic microbes and survived on the investigated surfaces and in an emulsion for more than 6 hours and 11 days, respectively.

Animals↗

[Effectiveness of oral administration of Lactobacillus paracasei subsp. paracasei F19 in association with vaginal suppositories of Lactobacillus acidofilus in the treatment of vaginosis and in the prevention of recurrent vaginitis].

AIM: The aim of this paper was to estimate the effectiveness of the contemporary oral administration of Lactobacilllus paracasei subsp paracasei F19 in association with vaginal suppositories containing Lactobacilllus acidofilus in the treatment of bacterial vaginosis and in the prevention of recurrent vaginitis. METHODS: We have recruited 60 women in good health, aged between 18 and 40 years with suspect or confirmed diagnosis of bacterial vaginosis. The women were randomized in 2 groups: Group A treated with vaginal suppositories containing Lactobacillus acidofilus (Calagin, SIFFRA, Florence); Group B treated with the same vaginal suppositories + probiotic containing Lactobacilllus paracasei subsp paracasei F 19 for oral administration (Gene-filus F19, SIFFRA, Florence). The patients were examined at the end of therapy (3 months) and then after 3 months from the end of treatment. RESULTS: In both groups at end of therapy there was a significant reduction of vaginal pH, an improvement of sniff test and of the subjective symptomatology after 3 months of treatment which still decreased during follow-up (3 months). In Group B there was a meaningful reduction of vaginal pH and of sniff test at the end of therapy and a maintenance of positive effect also after 3 months. CONCLUSIONS: The results obtained in this study show that the therapy with vaginal Lactobacillus in the treatment of bacterial vaginosis is successful. The association of oral administration is useful to balance the vaginal environment with the intestinal microflora with improvement of long-term results. The use of probiotics was determinant in the treatment of a pathology like bacterial vaginosis and as an alternative to the conventional local antibiotic therapies.

Adolescent↗

Mathematical description of the growth of Lactobacillus sake and Lactobacillus pentosus under conditions prevailing in fermented sausages.

The growth behaviour of Lactobacillus sake and Lactobacillus pentosus was determined in a model system stimulating the conditions of fermenting sausages. Minor effects on the growth were observed by varying the concentrations of glucose, peptone, manganese and sodium nitrite. Temperature and sodium chloride concentration were found to have most effect on the growth. The measured data were used for a mathematical model describing the growth response of L. sake and L. pentosus sufficiently well to estimate the behaviour of the investigated strains. In all combinations relevant to sausage fermentation L. sake proved to be more competitive. It exhibited a shorter lag phase, higher maximal growth rate and higher final cell yield than L. pentosus.

Fermentation↗

Energy conservation in malolactic fermentation by Lactobacillus plantarum and Lactobacillus sake.

A comparably poor growth medium containing 0.1% yeast extract as sole non-defined constituent was developed which allowed good reproducible growth of lactic acid bacteria. Of seven different strains of lactic acid bacteria tested, only Lactobacillus plantarum and Lactobacillus sake were found to catalyze stoichiometric conversion of L-malate to L-lactate and CO2 concomitant with growth. The specific growth yield of malate fermentation to lactate at pH 5.0 was 2.0 g and 3.7 g per mol with L. plantarum and L. sake, respectively. Growth in batch cultures depended linearly on the malate concentration provided. Malate was decarboxylated nearly exclusively by the cytoplasmically localized malo-lactic enzyme. No other C4-dicarboxylic acid-decarboxylating enzyme activity could be detected at significant activity in cell-free extracts. In pH-controlled continuous cultures, L. plantarum grew well with glucose as substrate, but not with malate. Addition of lactate to continuous cultures metabolizing glucose or malate decreased cell yields significantly. These results indicate that malo-lactic fermentation by these bacteria can be coupled with energy conservation, and that membrane energetization and ATP synthesis through this metabolic activity are due to malate uptake and/or lactate excretion rather than to an ion-translocating decarboxylase enzyme.

Decarboxylation↗

DNA restriction endonuclease cleavage patterns, DNA sequence similarity and phenotypical characteristics in some strains of Lactobacillus helveticus and Lactobacillus jugurti.

Physiological characteristics, deoxyribonucleic acid (DNA) base composition (% guanine + cytosine; + GC), DNA sequence similarity (% DNA-DNA hybridization) and DNA restriction endonuclease cleavage patterns of two strains of Lactobacillus helveticus and four strains of Lactobacillus jugurti were examined. All the strains investigated were closely related genetically, having DNA-DNA hybridization values ranging from 89-100%. Nevertheless, these strains can be differentiated from one another on the basis of the digestion of their DNA by specific restriction endonucleases, such as Bam HI, Eco RI and Hind III. The DNA of these strains shows clear, reproducible and distinct cleavage patterns. Cleavage patterns of DNA from strains L. jugurti S.35.19 and S.36.2 were found to be similar. These findings suggest that fingerprinting of DNA by restriction endonuclease cleavage might provide, in addition to the conventional methods, a useful tool for the characterization of closely related microorganisms at the strain level.

Base Composition↗

Evidence for chromosomal determination of fungicidal activity in strains of Lactobacillus brevis and Lactobacillus fermentum isolated from fermented foods.

The genetic basis of the fungicidal activity of strains of Lactobacillus brevis and L. fermentum isolated from indigenous fermented foods was determined. A 5.5-kb plasmid was isolated from L. brevis while L. Fermentum was found to harbor no plasmid. Plasmid curing indicated no correlation between the plasmid and the fungicidal activity of the Lactobacillus species. The fungicidal activity of the isolated organisms can be supposed to be mediated by the chromosome. No antibiotic resistance genetic markers were detected on the plasmid and hence it was classified as cryptic.

Anti-Bacterial Agents↗

Expression of Clostridium thermocellum endoglucanase gene in Lactobacillus gasseri and Lactobacillus johnsonii and characterization of the genetically modified probiotic lactobacilli.

Endoglucanase A from Clostridium thermocellum resistant to pancreatic proteinase was selected out of a range of microbial cellulases expressed in lactobacilli. Two Lactobacillus-E. coli expression vectors, harboring the endoglucanase gene from C. thermocellum under the control of its own promoter (pSD1) and the Lactococcus lactis lac A promoter (pSD2), were constructed separately. Intestinal Lactobacillus strains, L. gasseri and L. johnsonii, were electrotransformed with pSD1 and pSD2, and the stability of each plasmid was evaluated. The endoglucanase activities of 0.722 and 0.759 U/ml were respectively found in culture medium of L. gasseri and L. johnsonii containing pSD1, and of 0.407 U/ml in medium of L. gasseri harboring pSD2. When the probiotic characteristics such as acid-tolerance, bile-salt tolerance, and antibiotic susceptibility were investigated, L. gasseri and L. johnsonii were resistant to low pHs of 2 and 3. Also, L. johnsonii was bile-salt resistant in the presence of 0.5% oxgall and porcine bile extract. L. johnsonii and L. gasseri showed a rather homogeneous resistant pattern against tested antibiotics. Both strains were resistant to amikacin, bacitracin, gentamicin, streptomycin, kanamycin, and colistin.

Animals↗

Exopolysaccharides production in Lactobacillus bulgaricus and Lactobacillus casei exploiting microfiltration.

The physiology of Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus casei, extensively used in the dairy industry, was studied in order to evaluate key parameters in the synthesis of exopolysaccharides and to improve their production through novel fermentation processes. Selected strains were studied in shake flasks and in fermentor experiments using glucose and lactose as main carbon sources and bacto casitone as the only complex component, in a temperature range between 35 and 42 degrees C. The production of exopolysaccharides was monitored and correlated to the growth conditions using both a colorimetric assay and chromatographic methods. Fermentor experiments in batch mode yielded 100 mg l(-1) of EPS from L. bulgaricus and 350 mg l(-1) from L. casei. Moreover, the use of a microfiltration (MF) bioreactor resulted in exopolysaccharides (EPS) concentrations threefold and sixfold those of batch experiments, respectively. The monosaccharidic composition of the two analyzed polymers differed from those previously reported. The optimization of the production of EPSs using the MF fermentation strategy could permit the use of these molecules produced by generally recognised as safe (GRAS) microorganisms in the place of other polysaccharides in the food industry.

Bioreactors↗

Structure of an exocellular polysaccharide of Lactobacillus helveticus TN-4, a spontaneous mutant strain of Lactobacillus helveticus TY1-2.

Lactobacillus helveticus strain TN-4, a spontaneous mutant strain of Lactobacillus helveticus TY1-2, produced an exocellular polysaccharide from reconstituted skim milk. On the basis of the results of methylation analysis, enzymatic digestion, mild Smith degradation, mild acid hydrolysis, acetolysis, and 1D and 2D 1H-NMR spectroscopy, it was concluded that the polysaccharide has a D-galactofuranose containing hexasaccharide repeating unit with the following structure: [formula see text]

Animals↗

Comparative sequence analyses of the 16S rRNA genes of Lactobacillus minutus, Lactobacillus rimae and Streptococcus parvulus: proposal for the creation of a new genus Atopobium.

16S rRNA gene sequencing was performed on the species Lactobacillus minutus, Lactobacillus rimae and Streptococcus parvulus in order to clarify their taxonomic position. Based on comparative sequence analyses these organisms represent a hitherto unknown line of descent within the lactic acid group of bacteria for which a new genus, Atopobium gen. nov., is proposed.

Base Sequence↗