The effect of Lactobacillus casei and Bifidobacterium breve on antibiotic-associated diarrhea treatment: randomized double-blind clinical trial

INTRODUCTION: Antibiotic-associated diarrhea (AAD) is an important side effect of this specific class of drugs. The objective of this study was to investigate the effect of the use of probiotics in the treatment of AAD. METHODS: A group of hospitalized patients, who contracted diarrhea during or after 7 days of suspension of antimicrobial medication, was blindly randomized to receive a standardized diet associated with the use of the probiotics (Lactobacillus casei and Bifidobacterium breve) or its corresponding placebo, three times a day. RESULTS: Seventy patients were studied. For the experimental (n=35) and control (n=35) groups, respectively, the average time of treatment was 5.06±2.18 and 5.49±3.17 days (p=0.95), and the average duration of diarrhea, among those who were healed, was 4.87±2.13 and 4.52±2.55 days (p=0.36). Four (11.4%) patients who received probiotics and ten (28.6%) who received the placebo were not cured (p=0.13), and relapse rates were similar between both groups. Seven patients from each group, in addition to diarrhea, presented cases of bloating and/or abdominal cramps and/or vomiting (p=1.00). CONCLUSIONS: In this light, it is concluded that L. casei associated with B. breve, in the administered dosage and frequency, has no effect on the antibiotic-associated diarrhea. Similar studies need to be conducted with higher doses of these or other probiotics.

Genometrics as an essential tool for the assembly of whole genome sequences: the example of the chromosome of Bifidobacterium longum NCC2705.

BACKGROUND: Analysis of the first reported complete genome sequence of Bifidobacterium longum NCC2705, an actinobacterium colonizing the gastrointestinal tract, uncovered its proteomic relatedness to Streptomyces coelicolor and Mycobacterium tuberculosis. However, a rapid scrutiny by genometric methods revealed a genome organization totally different from all so far sequenced high-GC Gram-positive chromosomes. RESULTS: Generally, the cumulative GC- and ORF orientation skew curves of prokaryotic genomes consist of two linear segments of opposite slope: the minimum and the maximum of the curves correspond to the origin and the terminus of chromosome replication, respectively. However, analyses of the B. longum NCC2705 chromosome yielded six, instead of two, linear segments, while its dnaA locus, usually associated with the origin of replication, was not located at the minimum of the curves. Furthermore, the coorientation of gene transcription with replication was very low. Comparison with closely related actinobacteria strongly suggested that the chromosome of B. longum was misassembled, and the identification of two pairs of relatively long homologous DNA sequences offers the possibility for an alternative genome assembly proposed here below. By genometric criteria, this configuration displays all of the characters common to bacteria, in particular to related high-GC Gram-positives. In addition, it is compatible with the partially sequenced genome of DJO10A B. longum strain. Recently, a corrected sequence of B. longum NCC2705, with a configuration similar to the one proposed here below, has been deposited in GenBank, confirming our predictions. CONCLUSION: Genometric analyses, in conjunction with standard bioinformatic tools and knowledge of bacterial chromosome architecture, represent fast and straightforward methods for the evaluation of chromosome assembly.

Bifidobacterium longum Bacteremia in Preterm Infants Receiving Probiotics.

Administration of probiotics to premature newborns has been shown to prevent necrotizing enterocolitis and reduce all-cause mortality. In our hospital, we documented 2 cases of Bifidobacterium longum subspecies infantis bacteremia in newborns receiving probiotics. By comparative genomics, we confirmed that the strains isolated from each patient originated from the probiotics.

Administration of Bifidobacterium animalis subsp. lactis BB-12 and xylitol with a novel pacifier in early childhood

Probiotic bifidobacteria are used in the prevention and treatment of childhood diseases. On the other hand, these bacteria are also connected to dental caries. The purpose of the present work was to test a food supplement containing Bifidobacterium animalis subsp. lactis BB-12 (B. lactis BB-12) and xylitol, and to investigate its health effects, properties and safety when used in a novel pacifier in early childhood. In a double-blind, placebo-controlled trial, newborn infants (n=163) were assigned randomly to receive B. lactis BB-12, xylitol, or sorbitol from the age of 1– 2 monthsto 2 years with a pacifier or a spoon. Children were followed up to four years of age. A part of the parents participating in the clinical trial evaluated the feasibility of the novel administration method. The pattern of tablet release from the pouch of the pacifier was tested in adults. The food supplement tablet containing B. lactis BB-12 and xylitol could be delivered in a safe and controlled way with the novel pacifier. The early administration of B. lactis BB-12 did not result in permanent oral colonization of this probiotic or affect the colonization of mutans streptococci in early childhood. Moreover, B. lactis BB-12 did not increase the occurrence of caries. Controlled administration of B. lactis BB-12 significantly reduced the incidence of respiratory infections during the first eight months of life in a Finnish population with breastfed infants. To conclude, administration of B. lactis BB-12 in early childhood is safe with regard to the future dental health of the child. In addition, B. lactis BB-12 may add to the protection against respiratory infections provided by human breast milk in infancy.

Avaliação sensorial, microbiológica e de pós-acidificação durante a vida-de-prateleira de leites fermentados contendo Streptococcus thermophilus, Bifidobacterium longum e Lactobacillus acidophilus

Três leites fermentados, o primeiro por Str. thermophilus, o segundo por Bif. longum e o terceiro por Lb. acidophilus e o leite fermentado elaborado pela mistura de volumes iguais dos leites fermentados, separadamente, por Str. thermophilus, Bif. longum e Lb. acidophilus tiveram seu pH, acidez titulável, atributos sensoriais de sabor e acidez, e contagens de células viáveis determinadas, ao longo de 21 dias de estocagem a 4ºC. Não houve diferença significativa (p<0,05) para os atributos sensoriais entre o leite fermentado elaborado por mistura e aquele contendo apenas Str. thermophilus. O leite fermentado por Str. thermophilus apresentou a maior acidez e menor pH, enquanto o leite fermentado por Bif. longum apresentou a menor acidez e maior pH. As populações de Str. thermophilus e Bif. longum mantiveram-se constantes até 21 dias de estocagem, tanto nos leites fermentados isoladamente como no leite elaborado pela mistura, enquanto as populações de Lb. acidophilus apresentaram redução de um ciclo logarítmico.

Efeito prebiótico do mel sobre o crescimento e viabilidade de Bifidobacterium spp. e Lactobacillus spp. em leite

Para ser considerado prebiótico, um microrganismo deve atender a uma série de requisitos, sendo a manutenção da viabilidade, um dos principais. Culturas probióticas de Lactobacillus spp. e Bifidobacterium spp. foram cultivadas em leite em pó desnatado reconstituído 12% adicionado de 3% (p/v) de mel pasteurizado. Foram preparados controles sem mel. Todos os cultivos mantiveram-se viáveis por 46 dias a 7 °C atendendo o número mínimo exigido pela legislação. O maior número de células viáveis de L. casei-01 e L. casei Shirota (>9,0 log10 UFC.mL-1) foi observado nos cultivos contendo mel. A acidez titulável produzida por estas culturas foi de 1,44%. O número de células viáveis de L. acidophilus Sacco® aos 46 dias em cultivos com mel foi significativamente maior (p < 0,05) que nos controles. Considerando todo o período de estocagem, o mel exerceu efeito positivo significativo (p < 0,05) apenas para as culturas de Bifidobacterium. O menor crescimento e a menor acidificação no 46º dia foram observados nos cultivos de Bf. lactis Bb-12, sendo de 7,63 log10 UFC.mL-1 e 0,61% de acidez em presença de mel e 6,11 log10 UFC.mL-1 e 0,30% de acidez nos controles. Diferentemente, os cultivos de Bf. lactis Sacco® atingiram contagens de 9,11 log10 UFC.mL-1 e produziram 1,11% de acidez.

Lactobacillus helveticus R0052 et Bifidobacterium longum R0175 en combinaison réduisent l’apoptose dans le système limbique après ischémie myocardique transitoire chez le rat

Nous avons démontré la présence d'apoptose dans le système limbique suivant un infarctus du myocarde. Cette mort cellulaire serait partiellement reliée à l'augmentation de cytokines pro-inflammatoires. Des études démontrent que certains probiotiques ont des effets bénéfiques en diminuant le ratio de cytokines pro/anti-inflammatoires. La prise de probiotiques en prévention, avant l’occlusion d’une artère coronarienne, pourrait-elle diminuer l’apoptose dans le système limbique? Méthodes : La combinaison de probiotiques Lactobacillus helveticus R0052 et Bifidobacterium longum R0175 ou son véhicule fut additionné dans l’eau des rats pendant 28 jours consécutifs. Un infarctus du myocarde fut provoqué par l’occlusion de l’artère coronaire gauche. Après 40 minutes d'occlusion, les régions ischémiques ont été reperfusées pour 72 heures. Les animaux furent sacrifiés et la taille de l'infarctus mesurée. L'amygdale et l'hippocampe furent prélevés pour déterminer l'activité de la caspase-3 (pro-apoptotique), le ratio Bax/Bcl2(proapoptotique/ anti-apoptotique) et l'activité d'Akt (survie cellulaire). Résultats : La taille de l’infarctus n'est pas diminuée dans le groupe probiotique (45% de la région à risque)comparé au groupe placebo. Nos marqueurs d’apoptose démontrent une diminution dans les régions du gyrus denté, de l’amygdale latérale et médiane dans le groupe probiotique par rapport au placebo. L’activité de la caspase-3 et le ratio Bax:Bcl2 furent réduits dans le groupe probiotique de 50% et 40% respectivement (p < 0.05) et phosphorylation d’Akt fut augmentée de 35% (p<0.05). Aucune différence fut observée pour les régions Ca1 et Ca3. Conclusion : La combinaison de probiotiques utilisée réduit l’apoptose dans différentes régions du système limbique 72 heures après un IM.

Effet des probiotiques Lactobacillus helveticus RO052 et Bifidobacterium longum RO175 sur la dépression post-infarctus du myocarde chez le rat

Nous avons déjà démontré que les probiotiques réduisaient l'apoptose observée dans le système limbique après un infarctus du myocarde (IM), suggérant un rôle anti-dépresseur potentiel des probiotiques. Cette étude a été conçue pour déterminer si les probiotiques pouvaient atténuer le comportement dépressif observé après un infarctus du myocarde. Un autre objectif visait à démontrer qu’une altération de la barrière intestinale pourrait avoir lieu lors d’un IM et que les probiotiques pourraient empêcher cette altération de la perméabilité intestinale. Méthodes: Des rats mâles Sprague-Dawley ont reçu des probiotiques (1 milliard de cellules bactériennes vivantes de Lactobacillus helveticus R0052 et Bifidobacterium longum R0175) ou le véhicule tous les jours en dilution dans leur eau, débutant 1 semaine avant l'induction d'une ischémie myocardique. Un infarctus a ensuite été induit chez la moitié des rats, par l'occlusion de l'artère coronaire antérieure gauche (40 minutes) suivie d'une reperfusion. Les rats témoins, l'autre moitié de la cohorte, ont été soumis à la même procédure sans occlusion coronarienne. Une semaine après l'infarctus, les animaux ont été resoumis au traitement préalable jusqu'au moment du sacrifice. Le comportement dépressif a été évalué par trois tests soit: l'interaction sociale, le test de nage forcée et le test d'évitement passif. Résultats: Les résultats obtenus indiquent qu'en absence d'infarctus, les probiotiques n'ont pas d'effet significatif. Toutefois, en dépit de taille similaire IM, des rats traités avec des probiotiques, ont démontré davantage d'interactions sociales et une meilleure performance dans le test de nage forcée et d'évitement passif, comparativement à des rats du groupe IM sans probiotique (p<0,05). Conclusion: Les probiotiques atténuent le comportement dépressif observé après infarctus du myocarde par un mécanisme qui pourrait impliquer l'intégrité des intestins.

In vitro effects of phosphatidylcholine and transgalactooligosaccharides on the production of 1,2-sn-diacylglycerol by Bifidobacterium longum biovar infantis

Aims: To investigate the production of the tumour promoter 1,2-sn-diacylglycerol (DAG) by a human gut isolate of Bifidobacterium longum biovar infantis. Methods and Results: Bifidobacterium longum biovar infantis was grown in vitro using anaerobic static batch cultures in the presence of phosphatidylcholine (PC) and trans-galactooligosaccharides (TOS). Production of DAG was found to be dependent upon the presence of PC, while TOS had a reducing effect. Considerable differences in morphology, growth and metabolic end products from the micro-organism were observed under the different culture conditions. Conclusions: Our results have provided evidence that B. longum biovar infantis can produce DAG in vitro and that a prebiotic exerted a reducing effect upon this production. Significance and Impact of the Study: The results presented in this study demonstrate an ability of ostensibly beneficial member of the colonic environment to produce unwanted compounds under certain conditions. Therefore, it may be important that a combination of substrates and other factors are assessed when studying the behaviour of any bacterial group or species, especially when designing the dietary interventions.

Carbohydrate preference, acid tolerance and bile tolerance in five strains of Bifidobacterium

Aims: To assess the suitability of bifidobacteria for inclusion in synbiotic products on the basis of carbohydrate preference, acid and bile tolerance. Methods and Results: Five strains of Bifidobacterium were analysed for their carbohydrate preference from 12 substrates. Maximum growth rates were used to compare substrate preferences. Galacto-oligosaccharides and isomalto-oligosaccharides were well utilized by all the test species. Most bacteria tested could also utilize at least one type of fructan molecule. To determine transit tolerance of potentially probiotic bifidobacteria, acid and bile resistance was tested. A wide range acid resistance was found. Bile tolerance also varied. Conclusions: GOS and IMO were generally well utilized by the tested species. Other substrates were used to different degrees by the different species. Most bifidobacteria are poorly resistant to strongly acidic conditions with the exception of Bifidobacterium lactis Bb12. Bile tolerances were widely variable and it was shown that caution should be exercised when using colorimetric methods to assess bile tolerance. Significance and Impact of Study: The study allows the comparison of the properties of bifidobacteria, allowing a cost effective screen for the best species for use in synbiotic products to allow better survival and efficacy.

Exopolysaccharides produced by Bifidobacterium longum IPLA E44 and Bifidobacterium animalis subsp lactis IPLA R1 modify the composition and metabolic activity of human faecal microbiota in pH-controlled batch cultures

Exopolysaccharides (EPS) isolated from two Bifidobacterium strains, one of human intestinal origin (Bifidobacterium longum subsp. longum IPLA E44) and the other from dairy origin (Bifidobacterium animalis subsp. lactis IPLA R1), were subjected to in vitro chemically simulated gastrointestinal digestion. which showed the absence of degradation of both polymers in these conditions. Polymers were then used as carbon sources in pH-controlled faecal batch cultures and compared with the non-prebiotic carbohydrate glucose and the prebiotic inulin to determine changes in the composition of faecal bacteria. A set of eight fluorescent in situ hybridisation oligonucleotide probes targeting 16S rRNA sequences was used to quantify specific groups of microorganisms. Growth of the opportunistic pathogen Clostridium histolyticum occurred with all carbohydrates tested similarly to that found in negative control cultures without added carbohydrate and was mainly attributed to the culture conditions used rather than enhancement of growth by these substrates. Polymers E44 and RI stimulated growth of Lactobacillus/Enterococcus, Bifidobacterium, and Bacteroides/Prevotella in a similar way to that seen with inulin. The EPS RI also promoted growth of the Atopobium cluster during the first 24 h of fermentation. An increase in acetic and lactic acids was found during early stages of fermentation (first 10-24 h) correlating with increases of Lactobacillus, Bifidobacterium, and Atopobium. Propionic acid concentrations increased in old cultures, which was coincident with the enrichment of Clostridium cluster IX in cultures with EPS RI and with the increases in Bacteroides in cultures with both microbial EPS (RI and E44) and inulin. The lowest acetic to propionic acid ratio was obtained for EPS E44. None of the carbohydrates tested supported the growth of microorganisms from Clostridium clusters XIVa+b and IV, results that correlate with the poor butyrate production in the presence of EPS. Thus, EPS synthesized by bifidobacteria from dairy and intestinal origins can modulate the intestinal microbiota in vitro, promoting changes in some numerically and metabolically relevant microbial populations and shifts in the production of short chain fatty acids. (C) 2009 Elsevier B.V. All rights reserved.

Effect of storage temperature and media composition on the survivability of Bifidobacterium breve NCIMB 702257 in a malt hydrolisate

The aim of this study was to evaluate the survivability of Bifidobacterium breve NCIMB 702257 in a three malt-based media supplemented with cysteine and yeast extract, and to determine the protective effect of these growth factors. A number of parameterised mathematical models were used to predict of kinetics of viability and total acidity during storage at different temperatures. Results demonstrated a good fit to the experimental mathematical model. The Arrhenius equations showed only reasonable fits and the polynomial plots contained a large area without data between 4 and 25 degrees C. In addition, it was shown that cysteine promotes growth and acid production by bifidobacteria, but does not extend survivability. On the other hand, increasing the yeast extract content of the fermentation media enhances the survivability of B. breve. To our knowledge, this is the first study to address the modelling of the survivability of probiotic bacteria in a cereal based fermentation media at different temperatures, introducing a more quantitative approach to the study of the shelf-life of a probiotic product. (C) 2009 Elsevier B.V. All rights reserved.

Bifidobacterium scardovii sp. nov., from human sources

Five strains of an unusual catalase-negative Gram-positive asporogenous rod-shaped bacterium from human sources were subjected to a polyphasic taxonomic study. The presence of fructose-6-phosphate phosphoketolase, a key enzyme of bifidobacterial hexose metabolism, indicated the strains were members of the genus Bifidobacterium but they did not correspond to any of the recognized species of this genus on the basis of biochemical profiles and whole-cell protein analyses. Comparative 16S rRNA gene sequencing confirmed the placement of the isolates in the genus Bifidobacterium, and demonstrated they represent a hitherto unknown subline within the genus displaying > 5% sequence divergence with recognized species. Based on both phenotypic and phylogenetic criteria, it is proposed that the isolates recovered from human sources be classified as a new species, Bifidobacterium scardovii sp. nov.; the type strain is CCUG 13008T (= DSM 13734T).

In vitro fermentation of rice bran combined with Lactobacillus acidophilus 14 150B or Bifidobacterium longum 05 by the canine faecal microbiota

The fermentability of rice bran (RB), alone or in combination with one of two probiotics, by canine faecal microbiota was evaluated in stirred, pH-controlled, anaerobic batch cultures. RB enhanced the levels of bacteria detected by probes Bif164 (bifidobacteria) and Lab158 (lactic acid bacteria); however, addition of the probiotics did not have a significant effect on the predominant microbial counts compared with RB alone. RB sustained levels of Bifidobacterium longum 05 throughout the fermentation; in contrast, Lactobacillus acidophilus 14 150B levels decreased significantly after 5-h fermentation. RB fermentation induced changes in the short-chain fatty acid (SCFA) profile. However, RB combined with probiotics did not alter the SCFA levels compared with RB alone. Denaturing gradient gel electrophoresis analysis of samples obtained at 24 h showed a treatment effect with RB, which was not observed in the RB plus probiotic systems. Overall, the negative controls displayed lower species richness than the treatment systems and their banding profiles were distinct. This study illustrates the ability of a common ingredient found in pet food to modulate the canine faecal microbiota and highlights that RB may be an economical alternative to prebiotics for use in dog food.

Comparative effects of six probiotic strains on immune function in vitro

There is considerable interest in the strain specificity of immune modulation by probiotics. The present study compared the immunomodulatory properties of six probiotic strains of different species and two genera in a human peripheral blood mononuclear cell (PBMC) model in vitro. Live cells of lactobacilli (Lactobacillus casei Shirota, L. rhamnosus GG, L. plantarum NCIMB 8826 and L. reuteri NCIMB 11951) and bifidobacteria (Bifidobacterium longum SP 07/3 and B. bifidum MF 20/5) were individually incubated with PBMC from seven healthy subjects for 24 h. Probiotic strains increased the proportion of CD69+ on lymphocytes, T cells, T cell subsets and natural killer (NK) cells, and increased the proportion of CD25+, mainly on lymphocytes and NK cells. The effects on activation marker expression did not appear to be strain specific. NK cell activity was significantly increased by all six strains, without any significant difference between strains. Probiotic strains increased production of IL-1β, IL-6, IL-10, TNF-α, granulocyte-macrophage colony-stimulating factor and macrophage inflammatory protein 1α to different extents, but had no effect on the production of IL-2, IL-4, IL-5 or TNF-β. The cytokines that showed strain-specific modulation included IL-10, interferon-γ, TNF-α, IL-12p70, IL-6 and monocyte chemotactic protein-1. The Lactobacillus strains tended to promote T helper 1 cytokines, whereas bifidobacterial strains tended to produce a more anti-inflammatory profile. The results suggest that there was limited evidence of strain-specific effects of probiotics with respect to T cell and NK cell activation or NK cell activity, whereas production of some cytokines was differentially influenced by probiotic strains.