Enhanced clearance of Candida albicans from the oral cavities of mice following oral administration of Lactobacillus acidophilus

Orally administered live Lactobacillus acidophilus was assessed for its capacity to enhance clearance from the oral cavity of DBA/2 mice shown previously to be 'infection prone'. L. acidophilus fed to DBA/2 mice significantly shortened the duration of colonization of the oral cavity compared to controls. Enhanced clearance of Candida albicans correlated with both early mRNA gene expression for interleukin (IL)-4 and interferon (IFN)-gamma and expression of their secreted products in cultures of cervical lymph nodes stimulated with Candida antigen. In addition rapid clearance correlated with higher levels of IFN-gamma and nitric oxide in saliva. Delayed clearance, less pronounced levels of the cytokine response, saliva IFN-gamma and nitric oxide, and later mRNA expression for IL-4 and IFN-gamma relative to feeding with the L. acidophilus isolate were noted in mice fed a different Lactobacillus isolate (L. fermentum). These observations indicate significant variations in individual isolates to activate the common mucosal system.

Is Lactobacillus rhamnosus GG effective in preventing the onset of antibiotic-associated diarrhoea: A systematic review

Objective: To evaluate the efficacy of Lactobacillus rhamnosus GG in the prevention of antibiotic-associated diarrhoea. Data Sources: A computer-based search of MED-LINE, CINAHL, AMED, the Cochrane Controlled Trials Register and the Cochrane Database of Systematic Reviews was conducted. A hand-search of the bibliographies of relevant papers and previous meta-analyses was undertaken. Review Methods: Trials were included in the review if they compared the effects of L. rhamnosus GG and placebo and listed diarrhoea as a primary end-point. Studies were excluded if they were not placebo-controlled or utilised other probiotic strains. Results:Six trials were found that met all eligibility requirements. Significant statistical heterogeneity of the trials precluded meta-analysis. Four of the six trials found a significant reduction in the risk of antibiotic-associated diarrhoea with co-administration of Lactobacillus GG. One of the trials found a reduced number of days with antibiotic-induced diarrhoea with Lactobacillus GG administration, whilst the final trial found no benefit of Lactobacillus GG supplementation. Conclusion: Additional research is needed to further clarify the effectiveness of Lactobacillus GG in the prevention of antibiotic-associated diarrhoea. Copyright (c) 2005 S. Karger AG, Basel.

Genomic diversity of Lactobacillus salivarius

Lactobacillus salivarius is unusual among the lactobacilli due to its multireplicon genome architecture. The circular megaplasmids harboured by L. salivarius strains encode strain-specific traits for intestinal survival and probiotic activity. L. salivarius strains are increasingly being exploited for their probiotic properties in humans and animals. In terms of probiotic strain selection, it is important to have an understanding of the level of genomic diversity present in this species. Comparative genomic hybridization (CGH) and multilocus sequence typing (MLST) were employed to assess the level of genomic diversity in L. salivarius. The wellcharacterised probiotic strains L. salivarius UCC118 was employed as a genetic reference strain. The group of test strains were chosen to reflect the range of habitats from which L. salivarius strains are frequently recovered, including human, animal, and environmental sources. Strains of L. salivarius were found to be genetically diverse when compared to the UCC118 genome. The most conserved strains were human GIT isolates, while the greatest level of divergence were identified in animal associated isolates. MLST produced a better separation of the test strains according to their isolation origins, than that produced by CGHbased strain clustering. The exopolysaccharide (EPS) associated genes of L. salivarius strains were found to be highly divergent. The EPS-producing phenotype was found to be carbonsource dependent and inversely related to a strain's ability to produce a biofilm. The genome of the porcine isolate L. salivarius JCM1046 was shown by sequencing to harbour four extrachromosomal replicons, a circular megaplasmid (pMP1046A), a putative chromid (pMP1046B), a linear megaplasmid (pLMP1046) and a smaller circular plasmid (pCTN1046) which contains an integrated Tn916-like element (Tn6224), which carries the tetracycline resistance gene tetM. pLMP1046 represents the first sequence of a linear plasmid in a Lactobacillus species. Dissemination of antibiotic resistance genes among species with food or probiotic-association is undesirable, and the identification of Tn6224-like elements in this species has implications for strain selection for probiotic applications. In summary, this thesis used a comparative genomics approach to examine the level of genotypic diversity in L. salivarius, a species which contains probiotic strains. The genome sequence of strain JCM1046 provides additional insight into the spectrum of extrachromosomal replicons present in this species.

Deconjugated Bile Salts Produced by Extracellular Bile-Salt Hydrolase-Like Activities from the Probiotic Lactobacillus johnsonii La1 Inhibit Giardia duodenalis In vitro Growth

Giardiasis, currently considered a neglected disease, is caused by the intestinal protozoan parasite Giardia duodenalis and is widely spread in human as well as domestic and wild animals. The lack of appropriate medications and the spread of resistant parasite strains urgently call for the development of novel therapeutic strategies. Host microbiota or certain probiotic strains have the capacity to provide some protection against giardiasis. By combining biological and biochemical approaches, we have been able to decipher a molecular mechanism used by the probiotic strain Lactobacillus johnsonii La1 to prevent Giardia growth in vitro. We provide evidence that the supernatant of this strain contains active principle(s) not directly toxic to Giardia but able to convert non-toxic components of bile into components highly toxic to Giardia. By using bile acid profiling, these components were identified as deconjugated bile-salts. A bacterial bile-salt-hydrolase of commercial origin was able to mimic the properties of the supernatant. Mass spectrometric analysis of the bacterial supernatant identified two of the three bile-salt-hydrolases encoded in the genome of this probiotic strain. These observations document a possible mechanism by which L. johnsonii La1, by secreting, or releasing BSH-like activity(ies) in the vicinity of replicating Giardia in an environment where bile is present and abundant, can fight this parasite. This discovery has both fundamental and applied outcomes to fight giardiasis, based on local delivery of deconjugated bile salts, enzyme deconjugation of bile components, or natural or recombinant probiotic strains that secrete or release such deconjugating activities in a compartment where both bile salts and Giardia are present.

Desarrollo de una bebida probiótica de Aloe perfoliata var. vera (Sabila) utilizando Lactobacillus casei shirota

Se desarrolló una bebida probiótica utilizando Aloe perfoliata var. vera (Sábila) y una cepa liofilizada de Lactobacillus casei shirota. a partir de la obtención del jugo de las hojas de la planta Aloe perfoliata var. vera (sábila); el cual se utilizó en proporciones 10% (50 mL), 15% (75 mL), 20% (100 mL); se le agregó Goma Xantan como estabilizante, Ácido Cítrico como regulador de la acidez, azúcar de caña sin refinar como edulcorante y agua purificada. Se procedió a pasteurizar la bebida, para la posterior incorporación del microrganismo estandarizado Lactobacillus casei shirota a la concentración de 107 UFC/mL. Se realizó la medición de los parámetros de pH y Grados Brix, y además la determinación de Escherichia coli al jugo de Aloe perfoliata var. vera (sábila) sin pasteurizar y pasteurizado; Así mismo se evaluó la estabilidad del microorganismo estandarizado Lactobacillus casei shirota a la concentración de 107 UFC/mL en el jugo de Aloe perfoliata var. vera, mediante recuento en placa en agar MRS, durante los periodos de 1, 2, 5, 8 y 15 días. Finalmente, se realizó la prueba sensorial de Análisis Descriptivo Cualitativo que se llevó a cabo con dos grupos de catadores, un grupo conformado 25 docentes y el otro por 25 estudiantes, a los cuales se les dió una muestra de 30 mL de la bebida para valorar las características sensoriales y la aceptabilidad de la bebida con relación al aspecto, color, olor, sabor (dulce, acido, residual), fluidez, grumosidad y calidad general. Tomando en cuenta del estudio estabilidad de Lactobacillus casei shirora en el jugo de Aloe perfoliata var. vera pasteurizado, se concluyó que la muestra que brinda mejor estabilidad al componente probiótico es la muestra 2. (15% de jugo de sábila) cuya de una concentración inicial de 7.00E+07 UFC/mL que se mantiene por espacio de 2 días con una concentración superior a 1.00E+06 UFC/mL, finalizando a los 15 días con 6.00E+07UFC/mL, alcanzando el requerimiento mínimo 106 necesario para que la bebida sea considerada como probiótica; además en la prueba sensorial del análisis descriptivo cuantitativo la muestra 2 (15% de jugo de sábila), presento una buena aceptabilidad, tanto en estudiantes como en docentes, ambos géneros; logrando obtener un resultado de calidad general aceptable; el tiempo de vida útil de la bebida preparada fue de 8 días, considerando tanto los valores de pH y Grados Brix que presentaron una disminución luego de transcurrido el octavo día de análisis.

A Randomized Double-Blind Placebo-Controlled Trial of Lactobacillus reuteri for Chronic Functional Abdominal Pain in Children

Background: Functional abdominal pain (FAP) is one of the most common diseases, and large percentages of children suffer from it. Objectives: The purpose of the study was to evaluate the effect of Lactobacillus reuteri in treatment of children with functional abdominal pain. Patients and Methods: This study was a randomized double-blind placebo-controlled trial. Children aged 4 to 16 years with chronic functional abdominal pain (based on Rome III criteria) were enrolled in the study. They were randomly divided into two groups, one receiving probiotic and the other placebo. Results: Forty children received probiotic and forty others placebo. There were no significant differences in age, weight, sex, location of pain, associated symptoms, frequency and intensity of pain between the groups. The severity and frequency of abdominal pain in the first month compared to baseline was significantly less and at the end of the second month, there was no significant difference between both groups compared to the end of the first month. Conclusions: This study showed that the severity of pain was significantly reduced in both groups. There was no significant difference in pain scores between them. The effect of probiotic and placebo can probably be attributed to psychological effect of the drugs.

Lactobacillus rossiae, a vitamin B12 producer, represents a metabolically versatile species within the genus Lactobacillus

Lactobacillus rossiae is an obligately hetero-fermentative lactic acid bacterium, which can be isolated from a broad range of environments including sourdoughs, vegetables, fermented meat and flour, as well as the gastrointestinal tract of both humans and animals. In order to unravel distinctive genomic features of this particular species and investigate the phylogenetic positioning within the genus Lactobacillus, comparative genomics and phylogenomic approaches, followed by functional analyses were performed on L. rossiae DSM 15814(T), showing how this type strain not only occupies an independent phylogenetic branch, but also possesses genomic features underscoring its biotechnological potential. This strain in fact represents one of a small number of bacteria known to encode a complete de novo biosynthetic pathway of vitamin B-12 (in addition to other B vitamins such as folate and riboflavin). In addition, it possesses the capacity to utilize an extensive set of carbon sources, a characteristic that may contribute to environmental adaptation, perhaps enabling the strain's ability to populate different niches.

Lost in translation? The potential psychobiotic Lactobacillus rhamnosus (JB-1) fails to modulate stress or cognitive performance in healthy male subjects

Background: Preclinical studies have identified certain probiotics as psychobiotics a live microorganisms with a potential mental health benefit. Lactobacillus rhamnosus (JB-1) has been shown to reduce stress-related behaviour, corticosterone release and alter central expression of GABA receptors in an anxious mouse strain. However, it is unclear if this single putative psychobiotic strain has psychotropic activity in humans. Consequently, we aimed to examine if these promising preclinical findings could be translated to healthy human volunteers. Objectives: To determine the impact of L. rhamnosus on stress-related behaviours, physiology, inflammatory response, cognitive performance and brain activity patterns in healthy male participants. An 8 week, randomized, placebo-controlled, cross-over design was employed. Twenty-nine healthy male volunteers participated. Participants completed self-report stress measures, cognitive assessments and resting electroencephalography (EEG). Plasma IL10, IL1β, IL6, IL8 and TNFα levels and whole blood Toll-like 4 (TLR-4) agonist-induced cytokine release were determined by multiplex ELISA. Salivary cortisol was determined by ELISA and subjective stress measures were assessed before, during and after a socially evaluated cold pressor test (SECPT). Results: There was no overall effect of probiotic treatment on measures of mood, anxiety, stress or sleep quality and no significant effect of probiotic over placebo on subjective stress measures, or the HPA response to the SECPT. Visuospatial memory performance, attention switching, rapid visual information processing, emotion recognition and associated EEG measures did not show improvement over placebo. No significant anti-inflammatory effects were seen as assessed by basal and stimulated cytokine levels. Conclusions: L. rhamnosus was not superior to placebo in modifying stress-related measures, HPA response, inflammation or cognitive performance in healthy male participants. These findings highlight the challenges associated with moving promising preclinical studies, conducted in an anxious mouse strain, to healthy human participants. Future interventional studies investigating the effect of this psychobiotic in populations with stress-related disorders are required.

Draft genome sequence of Lactobacillus crispatus EM-LC1, an isolate with antimicrobial activity cultured from an elderly subject

Here we report the 1.86-Mb draft genome sequence of Lactobacillus crispatus EM-LC1, a fecal isolate with antimicrobial activity. This genome sequence is expected to provide insights into the antimicrobial activity of L. crispatus and improve our knowledge of its potential probiotic traits.

Oral Administration of Lactobacillus reuteri during the First Year of Life Reduces Caries Prevalence in the Primary Dentition at 9 Years of Age

The aim of this study was to evaluate the effect on oral health, at age 9 years, of daily oral supplementation with the probiotic Lactobacillus reuteri, strain ATCC 55730, to mothers during the last month of gestation and to children through the first year of life. The study was a single-blind, placebo-controlled, multicenter trial involving 113 children: 60 in the probiotic and 53 in the placebo group. The subjects underwent clinical and radiographic examination of the primary dentition and carious lesions, plaque and gingivitis were recorded. Saliva and plaque were sampled for determination of mutans streptococci (MS) and lactobacilli (LB) in saliva and plaque as well as salivary secretory IgA (SIgA). Forty-nine (82%) children in the probiotic group and 31 (58%) in the placebo group were caries-free (p < 0.01). The prevalence of approximal caries lesions was lower in the probiotic group (0.67 ± 1.61 vs. 1.53 ± 2.64; p < 0.05) and there were fewer sites with gingivitis compared to the placebo group (p < 0.05). There were no significant differences between the groups with respect to frequency of toothbrushing, plaque and dietary habits, but to intake of fluoride supplements (p < 0.05). There were no intergroup differences with respect to L. reuteri, MS, LB or SIgA in saliva. Within the limitation of this study it seems that daily supplementation with L. reuteri from birth and during the first year of life is associated with reduced caries prevalence and gingivitis score in the primary dentition at 9 years of age.

Bebida láctea caprina com suco de uva potencialmente probiótica: viabilidade de cepas de Lactobacillus rhamnosus e aceitabilidade sensorial.

Ojetivou-se desenvolver uma bebida láctea fermentada caprina adicionada de suco integral de uva, utilizando duas cepas de Lactobacillus rhamnosus, uma comercial e outra nativa, isolada a partir de queijos artesanais e selecionada em função de propriedades probióticas e tecnológicas .

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

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

The development of Lactococcus lactis as an antimicrobial agent

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