Comparative metatranscriptome analysis of Brazilian milk and water kefir beverages.

The present study compared bacterial and fungal diversity of kefir beverages produced using milk (MK) or sugared water (WK) as propagation matrices and grains from the cities of Curitiba (CU) or Salvador (SA), Brazil, by sequencing the complete set of RNA transcripts produced in four products. In Brazil, milk and sugared water are used as matrices to propagate kefir grains. In all beverages, the bacterial community was composed of Lactobacillaceae and Acetobacteraceae. Saccharomycetaceae was the yeast family more abundant in WK, and Dipodascaceae and Pichiaceae in MK. Regarding KEGG mapping of functional orthologs, the four kefir samples shared 70% of KO entries of yeast genes but only 36% of bacterial genes. Concerning main metabolic processes, the relative abundance of transcripts associated with metabolism (energy metabolism) and environmental information processing (membrane transport) had the highest water/milk kefir ratio observed in Firmicutes. In contrast, transcripts associated with genetic information processing (protein translation, folding, sorting, and degradation) oppositely had the lowest water/milk ratios. Concluding, milk and water kefir have quite different communities of microorganisms. Still, the main mapped functional processes are similar, with only quantitative variation in membrane transport and energy acquisition in the water kefir and protein synthesis and turnover in the milk kefir.

Impact of vitamin deficiency on microbiota composition and immunomodulation: relevance to autistic spectrum disorders.

OBJECTIVES: Inappropriate vitamin supply is a public health problem and is related to abnormalities in brain development, immune response and, more recently, in changes of gut microbial composition. It is known that low levels of vitamin in early life are linked to increased susceptibility to neurodevelopmental disorders, such as Autism Spectrum Disorders (ASD). Unfortunately, the possible peripheral influences of vitamin deficiency that leads to alterations in the gut microbiota-immune-brain axis, one important modulator of the ASD pathology, remain unclear. This narrative review discusses how the impact of vitamin deficiency results in changes in the immune regulation and in the gut microbiota composition, trying to understand how these changes may contribute for the development and severity of ASD. METHODS: The papers were selected using Pubmed and other databases. This review discusses the following topics: (1) vitamin deficiency in alterations of central nervous system in autism, (2) the impact of low levels of vitamins in immunomodulation and how it can favor imbalance in gut microbiota composition and gastrointestinal (GI) disturbances, (3) gut microbiota imbalance/inflammation associated with the ASD pathophysiology, and (4) possible evidences of the role of vitamin deficiency in dysfunctional gut microbiota-immune-brain axis in ASD. RESULTS: Studies indicate that hypovitaminosis A, B12, D, and K have been co-related with the ASD neuropathology. Furthermore, it was shown that low levels of these vitamins favor the Th1/Th17 environment in the gut, as well as the growth of enteropathogens linked to GI disorders. DISCUSSION: GI disorders and alterations in the gut microbiota-immune-brain axis seems to be linked with ASD severity. Although unclear, hypovitaminosis appears to regulate peripherally the ASD pathophysiology by modulating the gut microbiota-immune-brain axis, however, more research is still necessary to confirm this hypothesis.

Differential Immune Response of Lactobacillus plantarum 286 Against Salmonella Typhimurium Infection in Conventional and Germ-Free Mice.

We aimed at evaluating in vivo the probiotic potential of Lactobacillus plantarum 286 against Salmonella enterica serov. Typhimurium. Colonization capacity and antagonistic activity were determined in feces of gnotobiotic mice. Survival to infection, translocation, histopathology, IgA and cytokine levels (IL-10, IL-6, IFN-γ, TNF-α, TGF-ß) were determined both in conventional and germ-free mice followed L. plantarum 286 administration and Salmonella infection. L. plantarum 286 colonized the intestine of gnotobiotic mice, where it produced antagonistic substances against S. Typhimurium. In conventional animals, the administration of this strain increased intestinal IgA levels and reduced the inflammatory response and the tissue damage caused by S. Typhimurium. Reduction of tissue damage in the intestine and liver of germ-free animals was also observed, however the immune response elicited was different in either model. L. plantarum 286 showed in vivo probiotic properties in both murine models. Probiotic capacity results may depend on the animal model chosen.

Probiotics improve re-epithelialization of scratches infected by Porphyromonas gingivalis through up-regulating CXCL8-CXCR1/CXCR2 axis.

Porphyromonas gingivalis inhibits the release of CXCL8 by gingival epithelial cells and reduces their proliferation. We previously reported that Bifidocaterium sp. and Lactobacillus sp. immunomodulate gingival epithelial cells response to this periodontal pathogen, but their effects on re-epithelialization properties are still unknown. Herein we explored these activities of potential probiotics on gingival epithelial cells and clarified their mechanisms. The immortalized OBA-9 lineage was used to perform in vitro scratches. Twelve clinical isolates and commercially available strains of Bifidobacterium sp. and Lactobacillus sp. were screened. L. casei 324 m and B. pseudolongum 1191A were selected to perform mechanistic assays with P. gingivalis W83 infection and the following parameters were measured: percentage of re-epithelialization by DAPI immunofluorescence area measurement; cell number by Trypan Blue exclusion assay; CXCL8 regulation by ELISA and RT-qPCR; and expression of CXCL8 cognate receptors-CXCR1 and CXCR2 by Flow Cytometry. Complementary mechanistic assays were performed with CXCL8, in the presence or absence of the CXCR1/CXCR2 inhibitor-reparixin. L. casei 324 m and B. pseudolongum 1191A enhanced re-epithelialization/cell proliferation as well as inhibited the harmful effects of P. gingivalis W83 on these activities through an increase in the expression and release of CXCL8 and in the number of cells positive for CXCR1/CXCR2. Further, we revealed that the beneficial effects of these potential probiotics were dependent on activation of the CXCL8-CXCR1/CXCR2 axis. The current findings indicate that these potential probiotics strains may improve wound healing in the context of the periodontal tissues by a CXCL8 dependent mechanism.

Porcine stomachs with and without gastric ulcer differ in Lactobacillus load and strain characteristics.

Although Lactobacillus species are recognized as normal inhabitants of porcine gastric mucosa, the association of these bacteria with health status or gastric ulcer disease has never been considered. We investigated the bacterial load of Lactobacillus isolated from the antrum, corpus, and pars esophagea of stomachs with (n = 13) and without (n = 10) ulcer of the pars esophagea of slaughtered pigs. We also evaluated in vitro antagonistic properties against typical pathogens of strains isolated from stomachs without ulcer. To quantify Lactobacillus, gastric mucosa samples obtained with 5 mm biopsy punches were smeared on MRS agar and colonies were counted after 48 h of incubation under anaerobic conditions. The score of Lactobacillus was significantly greater in the antrum and corpus of stomachs without ulcer (P < 0.001 for both) when compared with stomachs with ulcer. Fingerprint profiles, obtained by repetitive sequence-based PCR using (GTG)5 primers, showed that the isolates were highly diverse. The reduction of Lactobacillus load in porcine stomachs may be a contributing factor for gastric ulcer. Strains isolated from healthy stomachs, which showed a wide spectrum of antagonistic activity against pathogens, may be viewed as an untapped source of bacteria with potential beneficial properties that deserve to be further investigated.

Selection of Lactic Acid Bacteria with Probiotic Potential Isolated from the Fermentation Process of "Cupuaçu" (Theobroma grandiflorum).

In the present study, nine lactic acid bacteria isolated from the fermentation process of "cupuaçu" (Theobroma grandiflorum) were selected for probiotic use. In vitro (resistance to gastrointestinal environment, in vitro antagonism and co-aggregation with pathogens) and in vivo (intestinal colonization and ex vivo antagonism in germ-free mice, cumulative mortality, translocation to liver and spleen, histopathological examination of liver and ileum and mRNA cytokine gene expression during an experimental infection with S. Typhimurium) assays were used. Among the nine Lactobacillus strains isolated from the "cupuaçu" fermentation, L. plantarum 81 and L. plantarum 90 were selected as potential probiotics based on better results obtained in in vitro evaluations (production of diffusible inhibitory compounds and co-aggregation) as well as in vivo experiments (resistance to gastrointestinal environment, ex vivo antagonism, higher survival after enteropathogen challenge, lower hepatic translocation of enteropathogen, lower histopathological lesions in ileum and liver and anti-inflammatory pattern of immunological response). Concluding, L. plantarum 81 and L. plantarum 90 showed in vitro and in vivo capacities for probiotic use through different mechanisms of protection and its origin would allow an easier adaptation in an alimentary matrix for its administration.

Selection of lactic acid bacteria from Brazilian kefir grains for potential use as starter or probiotic cultures.

Brazilian kefir is a homemade fermented beverage that is obtained by incubating milk or a brown sugar solution with kefir grains that contribute their different microbiological compositions. It is highly important to isolate and characterize microorganisms from Brazilian kefir grains to obtain starter cultures for the industrial production of a standardized commercial kefir. Thus, the present study aimed to isolate lactic acid bacteria from eight kefir grains that were propagated in milk or sugar solutions from five different locations in Brazil and to select Lactobacillus isolates based on desirable in vitro probiotic properties. One hundred eight isolates from both substrates were identified by amplified ribosomal DNA restriction analysis and/or 16S rRNA gene sequencing and were determined to belong to the following 11 species from the genera: Lactococcus, Leuconostoc, Lactobacillus (L.), and Oenococcus. Leuconostoc mesenteroides, Lactobacillus kefiri, and Lactobacillus kefiranofaciens were isolated only from milk grains, whereas Lactobacillus perolens, Lactobacillus parafarraginis, Lactobacillus diolivorans, and Oenococcus oeni were isolated exclusively from sugar water grains. When the microbial compositions of four kefir grains were evaluated with culture-independent analyses, L. kefiranofaciens was observed to predominant in milk grains, whereas Lactobacillus hilgardii was most abundant in sugar water kefir. Unfortunately, L. hilgardii was not isolated from any grain, although this bacteria was detected with a culture-independent methodology. Fifty-two isolated Lactobacilli were tested for gastric juice and bile salt tolerance, antagonism against pathogens, antimicrobial resistance, and surface hydrophobicity. Three Lactobacillus strains (L. kefiranofaciens 8U, L. diolivorans 1Z, and Lactobacillus casei 17U) could be classified as potential probiotics. In conclusion, several lactic acid bacteria that could be used in combination with yeasts as starter cultures for both milk kefir and sugar water kefir were characterized, and the functional properties of several of the lactobacilli isolated from the kefir grains were suggestive of their possible use as probiotics in both kefir and other dairy products.

Use of Probiotics to Control Aflatoxin Production in Peanut Grains.

Probiotic microorganisms (Saccharomyces cerevisiae var. boulardii, S. cerevisiae UFMG 905, and Lactobacillus delbrueckii UFV H2b20) were evaluated as biological control agents to reduce aflatoxin and spore production by Aspergillus parasiticus IMI 242695 in peanut. Suspensions containing the probiotics alone or in combinations were tested by sprinkling on the grains followed by incubation for seven days at 25°C. All probiotic microorganisms, in live and inactivated forms, significantly reduced A. parasiticus sporulation, but the best results were obtained with live cells. The presence of probiotics also altered the color of A. parasiticus colonies but not the spore morphology. Reduction in aflatoxin production of 72.8 and 65.8% was observed for S. boulardii and S. cerevisiae, respectively, when inoculated alone. When inoculated in pairs, all probiotic combinations reduced significantly aflatoxin production, and the best reduction was obtained with S. boulardii plus L. delbrueckii (96.1%) followed by S. boulardii plus S. cerevisiae and L. delbrueckii plus S. cerevisiae (71.1 and 66.7%, resp.). All probiotics remained viable in high numbers on the grains even after 300 days. The results of the present study suggest a different use of probiotics as an alternative treatment to prevent aflatoxin production in peanut grains.

L-arginine supplementation prevents increases in intestinal permeability and bacterial translocation in male Swiss mice subjected to physical exercise under environmental heat stress.

Dietary supplementation with l-arginine has been shown to improve the intestinal barrier in many experimental models. This study investigated the effects of arginine supplementation on the intestinal permeability and bacterial translocation (BT) induced by prolonged physical exercise under heat stress. Under anesthesia, male Swiss mice (5-wk-old) were implanted with an abdominal sensor to record their core body temperature (T(core)). After recovering from surgery, the mice were divided into 3 groups: a non-supplemented group that was fed the standard diet formulated by the American Institute of Nutrition (AIN-93G; control), a non-supplemented group that was fed the AIN-93G diet and subjected to exertional hyperthermia (H-NS), and a group supplemented with l-arginine at 2% and subjected to exertional hyperthermia (H-Arg). After 7 d of treatment, the H-NS and H-Arg mice were forced to run on a treadmill (60 min, 8 m/min) in a warm environment (34°C). The control mice remained at 24°C. Thirty min before the exercise or control trials, the mice received a diethylenetriamine pentaacetic acid (DTPA) solution labeled with technetium-99m ((99m)Tc-DTPA) or (99m)Tc-Escherichia coli by gavage to assess intestinal permeability and BT, respectively. The H-NS mice terminated the exercise with T(core) values of ∼40°C, and, 4 h later, presented a 12-fold increase in the blood uptake of (99m)Tc-DTPA and higher bacterial contents in the blood and liver than the control mice. Although supplementation with arginine did not change the exercise-induced increase in T(core), it prevented the increases in intestinal permeability and BT caused by exertional hyperthermia. Our results indicate that dietary l-arginine supplementation preserves the integrity of the intestinal epithelium during exercise under heat stress, acting through mechanisms that are independent of T(core) regulation.

A Functional Bread Fermented with Saccharomyces cerevisiae UFMG A-905 Prevents Allergic Asthma in Mice.

Background: The administration of probiotics has been shown to be beneficial in asthma. The administration of Saccharomyces cerevisiae UFMG A-905 prevented asthma development. Traditionally, probiotics are administered using dairy-based matrices, but other vehicles (e.g., fruit juices, biscuits, candies, and breads) can be used. Objectives: This study aimed to assess the effect of bread fermented with S. cerevisiae UFMG A-905 in asthma prevention. Methods: Three breads were produced: fermented with commercial yeast, fermented with S. cerevisiae UFMG A-905, and fermented with S. cerevisiae UFMG A-905 with the addition of alginate microcapsules containing live S. cerevisiae UFMG A-905. Characterization of the microbial composition of the breads was performed. Male Balb/c mice were sensitized and challenged with ovalbumin. Breads were administered 10 d before the first sensitization and during sensitization and challenge protocol. Yeast fecal count, in vivo airway hyperresponsiveness, and airway and lung inflammation were assessed. Results: In UFMG A-905 bread, there was an increase in yeast number and a decrease in total and lactic acid bacteria. Animals that received S. cerevisiae UFMG A-905 fermented bread with microcapsules had a significant increase in yeast recovery from feces. S. cerevisiae UFMG A-905-fermented breads partially reduced airway inflammation, decreasing eosinophils and IL5 and IL13 concentrations. When adding microcapsules, the bread also diminished airway hyperresponsiveness and increased IL17A concentrations. Conclusions: S. cerevisiae UFMG A-905 was able to generate long-fermentation breads. Microcapsules were a safe and viable way to inoculate the live yeast into food. The administration of breads fermented with S. cerevisiae UFMG A-905 prevented asthma-like characteristics, being more pronounced when the breads contained microcapsules with live yeast.

The role of L-arginine-nitric oxide pathway in bacterial translocation.

This study investigated the nitric oxide (NO) role as a mediator of arginine on bacterial translocation (BT) and gut damage in mice after intestinal obstruction (IO). The effects of pretreatment with arginine with or without NO inhibition on the systemic and local immunological response were also assessed. Mice were categorized into four groups. Group ARG received chow containing 2 % arginine, while group ARG + L-NAME received the same diet plus L-NAME (N-nitro-L-arginine methyl ester) by gavage. The IO and Sham groups were fed standard chow. After 7 days, animals were gavaged with radiolabeled Escherichia coli, anesthetized and subjected to IO, except the Sham group. Animals were euthanized after 18 h, and BT was evaluated in the mesenteric lymph nodes, blood, liver, spleen and lungs. In another experiment, the intestinal injury was assessed regarding intestinal permeability and ileum histological analyses. Intestinal secretory immunoglobulin A (sIgA) levels, serum IFN-γ and IL-10 cytokines were assessed. Arginine reduced BT, but NO inhibition enhanced BT compared with the ARG group (p < 0.05). Intestinal permeability in the ARG and ARG + L-NAME groups was similar but decreased when compared with the IO group (p < 0.05). Histological preservation was observed. Arginine treatment increased IL-10 and sIgA levels when compared with the Sham and IO groups (p < 0.05). The cytokines and sIgA concentrations were similar in the ARG + L-NAME and Sham groups. Arginine appeared to reduce BT and its effects on the modulation of cytokines and secretory IgA in mice after IO are mediated by NO production.

Monoassociation with probiotic Lactobacillus delbrueckii UFV-H2b20 stimulates the immune system and protects germfree mice against Listeria monocytogenes infection.

In the present study, we investigated the protective effects of Lactobacillus delbrueckii UFV-H2b20 on the resistance to Listeria monocytogenes infection in gnotobiotic mice. Germfree mice or monoassociated mice were infected with L. monocytogenes, and the microbiological and immunological responses were evaluated after 1, 3, and 5 days of infection. Monoassociation with L. delbrueckii was capable of protecting mice against death caused by L. monocytogenes and induced a faster clearance of the bacteria in the liver, spleen, and peritoneal cavity at days 1, 3, and 5 post-infection. Also, monoassociated mice displayed less liver injury than germfree mice. The production of TNF-α in the serum, peritoneal cavity, and gut was augmented in monoassociated mice. Likewise, the levels of IFN-γ found on supernatants of spleen cells cultures were higher after the monoassociation. In addition, increased production of nitric oxide in peritoneal cell cultures supernatants and in serum was observed in mice that received L. delbrueckii. The monoassociation with L. delbrueckii induced higher production of IL-10 in the mucosal immune system. We conclude that monoassociation with L. delbrueckii UFV-H2b20 protects mice from death caused by L. monocytogenes infection by favoring effector responses while preventing their immunopathological consequences.

Evaluation of Royal Sun Agaricus, Agaricus brasiliensis S. Wasser et al., aqueous extract in mice challenged with Salmonella enterica serovar Typhimurium.

This study investigated the effects of Agaricus brasiliensis S. Wasser et al. (=Agaricus blazei Murrill sensu Heinem.) aqueous extract on small intestinal sIgA levels, serum TNF-alpha, IFN-gamma and IL-10 levels, splenic index, bacterial translocation, and histology of small intestine, spleen, and liver from mice orally challenged with 10(6) CFU of Salmonella enterica serovar Typhimurium (SEST). Splenic index values as well as sIgA, TNF-alpha, IFN-gamma, and IL-10 levels were not affected by either A. brasiliensis aqueous extract treatment or by pathogenic challenge. Typical colonies of SEST were recovered from liver, spleen, and mesenteric lymph nodes of challenged animals, but there was no significant difference in this translocation between groups treated or not with A. brasiliensis aqueous extract. Translocation was confirmed by histopathological analysis in mice challenged with SEST, which showed small and diffuse foci of mixed inflammatory infiltrate in hepatic parenchyma. In conclusion, A. brasiliensis aqueous extract as tested in the present study did not influence any of the variables selected to evaluate in vivo its immunomodulatory effect suggested in the literature.

Synergistic growth effect among bacteria recovered from root canal infections.

The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.

Lactobacillus rhamnosus CGMCC 1.3724 (LPR) Improves Skin Wound Healing and Reduces Scar Formation in Mice.

Skin wounds are an important clinical problem which affects millions of people worldwide. The search for new therapeutic approaches to improve wound healing is needed. The present study aimed to evaluate the effects of the oral treatment with the skin-related probiotics Lactobacillus johnsonii LA1 (LJ), L. paracasei ST11 (LP), and L. rhamnosus LPR (LR) in a model of excisional skin wounds in Swiss mice. The animals received daily oral gavage of PBS or 1 × 107 colony-forming units of LJ, LP, or LR, singly, beginning just after the creation of wounds until euthanasia. Blood flow was evaluated by laser Doppler perfusion imaging. Myeloperoxidase and N-acetyl-ß-D-glucosaminidase activities were used to assess the accumulation of neutrophils and macrophages, respectively. The wound tissue was also collected for histological analyses (H&E, Toluidine blue, and Picrosirius red staining). The macroscopic wound closure rate was faster only in mice treated with LR, but not with LJ and LP, when compared to mice treated with PBS. Histological evaluations showed that treatment with LR stimulated wound epithelization when compared to PBS. Further analyses showed that wounds from LR-treated mice presented a significant decrease in macrophage (p < 0.001) and mast cell (p < 0.001) infiltration, along with improved angiogenesis (p < 0.001) and blood flow (p < 0.01). Of note, collagen deposition and scarring were reduced in LR-treated mice when compared to PBS-treated mice. In conclusion, our results show that the oral treatment with Lactobacillus rhamnosus accelerates skin wound closure and reduces scar, besides to reducing inflammation and fibrogenesis and improving angiogenesis in the wounded skin.

Comparative genomics and in silico gene evaluation involved in the probiotic potential of Bifidobacterium longum 51A.

The Bifidobacterium longum 51A strain of isolated from feces of a healthy child, has demonstrated probiotic properties by in vivo and in vitro studies, which may be assigned to its production of metabolites such as acetate. Thus, through the study of comparative genomics, the present work sought to identify unique genes that might be related to the production of acetate. To perform the study, the DNA strain was sequenced using Illumina HiSeq technology, followed by assembly and manual curation of coding sequences. Comparative analysis was performed including 19 complete B. longum genomes available in Genbank/NCBI. In the phylogenetic analysis, the CECT 7210 and 157F strains of B. longum subsp. infantis aggregated within the subsp. longum cluster, suggesting that their taxonomic classification should be reviewed. The strain 51A of B. longum has 26 unique genes, six of which are possibly related to carbohydrate metabolism and acetate production. The phosphoketolase pathway from B. longum 51A showed a difference in acetyl-phosphate production. This result seems to corroborate the analysis of their unique genes, whose presence suggests the strain may use different sources of carbohydrates that allow a greater production of acetate and consequently offer benefits to the host health.

Probiotics alter biofilm formation and the transcription of Porphyromonas gingivalis virulence-associated genes.

BACKGROUND AND OBJECTIVE: The potential of probiotics on the prevention and control of periodontitis and other chronic inflammatory conditions has been suggested. Lactobacillus and Bifidobacterium species influence P. gingivalis interaction with gingival epithelial cells (GECs) but may not act in a unique way. In order to select the most appropriate probiotic against P. gingivalis, we aimed to evaluate the effect of several strains on Porphyromonas gingivalis biofilm formation and transcription virulence-associated factors (PgVAFs). METHODS: Cell-free pH neutralized supernatants (CFS) and living Lactobacillus spp. and Bifidobacterium spp. were tested against P. gingivalis ATCC 33277 and W83, in mono- and multi-species (with Streptococcus oralis and S. gordonii) biofilms. Relative transcription of P. gingivalis genes (fimA, mfa1, kgp, rgp, ftsH and luxS) was determined in biofilms and under GECs co-infection. RESULTS: Probiotics CFS reduced P. gingivalis ATCC 33277 levels in mono-species biofilms and living probiotics reduced P. gingivalis abundance in multi-species biofilms. L. acidophilus LA5 down-regulated transcription of most PgVAFs in biofilms and GECs. CONCLUSIONS: Probiotics affect P. gingivalis biofilm formation by down-regulating overall PgVAFs with the most pronounced effect observed for L. acidophilus LA5.

Milk Fermented by Lactobacillus paracasei NCC 2461 (ST11) Modulates the Immune Response and Microbiota to Exert its Protective Effects Against Salmonella typhimurium Infection in Mice.

Probiotics form a promising strategy to maintain intestinal health. Milks fermented with probiotic strains, such as the Lactobacillus paracasei ST11, are largely commercialized in Brazil and form a low-cost alternative to probiotic pharmaceutical formulations. In this study, we assessed the probiotic effects of milk fermented by L. paracasei ST11 (administered through fermented milk) in a Salmonella typhimurium infection model in BALB/c mice. We observed in this murine model that the applied probiotic conferred protective effects against S. typhimurium infection, since its administration reduced mortality, weight loss, translocation to target organs (liver and spleen) and ileum injury. Moreover, a reduction in the mRNA expression of pro-inflammatory cytokines such as IFN-γ, IL-6, TNF-α and IL-17 in animals that received the probiotic before challenge was observed. Additionally, the ileum microbiota was better preserved in these animals. The present study highlights a multifactorial protective aspect of this commercial probiotic strain against a common gastrointestinal pathogen.

Comparative study of Bifidobacterium animalis, Escherichia coli, Lactobacillus casei and Saccharomyces boulardii probiotic properties.

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.

A common vaginal microbiota composition among breeds of Bos taurus indicus (Gyr and Nellore).

Describing the bovine vaginal microbiota is essential to better understand its physiology and its impact on health maintenance. Despite the economic importance of reproduction of these animals, bovine vaginal microbial community is still poorly described in comparison with rumen microbiome. Previous studies of our group described the vaginal microbiota of Nellore, an important Bos taurus indicus breed, using metagenomics. In order to better understand this microbiota, the present work aims to investigate another important breed, Gyr. Results have shown bacterial dominance over Archaea and Fungi was observed, with the most abundant bacterial phylum (Firmicutes) representing 40-50% of bacterial population, followed by Bacteroidetes, Proteobacteria, and Actinobacteria. The Fungi kingdom had the Mycosphaerella genus as its main representative, followed by Cladosporium. Archaea were observed at a very low abundance in all animals, with a high relative abundance of Methanobrevibacter genus. These results demonstrate a high microbial diversity on vaginal tract of Gyr, as demonstrated for Nellore and different from the previously described for other species. Our results indicate a great similarity between vaginal microbiota of Nellore and Gyr despite the differences in animal handling and genetic improvement. As observed for both breeds, individual variation is the largest source of microbial diversity between animals.