Interaction of Saccharomyces boulardii with Salmonella enterica Serovar Typhimurium Protects Mice and Modifies T84 Cell Response to the Infection

BACKGROUND: Salmonella pathogenesis engages host cells in two-way biochemical interactions: phagocytosis of bacteria by recruitment of cellular small GTP-binding proteins induced by the bacteria, and by triggering a pro-inflammatory response through activation of MAPKs and nuclear translocation of NF-kappaB. Worldwide interest in the use of functional foods containing probiotic bacteria for health promotion and disease prevention has increased significantly. Saccharomyces boulardii is a non-pathogenic yeast used as a probiotic in infectious diarrhea. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we reported that S. boulardii (Sb) protected mice from Salmonella enterica serovar Typhimurium (ST)-induced death and prevented bacterial translocation to the liver. At a molecular level, using T84 human colorectal cancer cells, we demonstrate that incubation with Sb before infection totally abolished Salmonella invasion. This correlates with a decrease of activation of Rac1. Sb preserved T84 barrier function and decreased ST-induced IL-8 synthesis. This anti-inflammatory effect was correlated with an inhibitory effect of Sb on ST-induced activation of the MAPKs ERK1/2, p38 and JNK as well as on activation of NF-kappaB. Electron and confocal microscopy experiments showed an adhesion of bacteria to yeast cells, which could represent one of the mechanisms by which Sb exerts its protective effects. CONCLUSIONS: Sb shows modulating effects on permeability, inflammation, and signal transduction pathway in T84 cells infected by ST and an in vivo protective effect against ST infection. The present results also demonstrate that Sb modifies invasive properties of Salmonella

Lipid droplet levels vary heterogeneously in response to simulated gastrointestinal stresses in different probiotic Saccharomyces cerevisiae strains

AbstractTo exert their therapeutic action, probiotic Saccharomyces cerevisiae strains must survive harsh digestive environments. Lipid droplets accumulate in cells which undergo stress-inducing situations, supposedly having a protective role. We assessed lipid droplet levels, either naturally accumulated or induced in response to digestive challenges, of probiotic strains S. boulardii, S. cerevisiae A-905, S. cerevisiae Sc47 and S. cerevisiae L11, and of non-probiotic strains S. cerevisiae BY4741 and S. cerevisiae BY4743. Strains 905 and Sc47 had lower and higher lipid droplet levels, respectively, when compared to the remaining strains, showing that higher accumulationof these neutral lipids is not a feature shared by all probiotic Saccharomyces strains. When submitted to simulated gastric or bile salts environments, lipid droplet levels increase in all tested probiotic strains, at least for one to the induced stresses, suggesting that lipid droplets participate in the protective mechanisms against gastrointestinal stresses in probiotic Saccharomyces yeasts

Oral treatment with Saccharomyces cerevisiae strain UFMG 905 modulates immune responses and interferes with signal pathways involved in the activation of inflammation in a murine model of typhoid fever

AbstractSalmonella spp. are Gram-negative, facultative, intracellular pathogens that cause several diarrheal diseases ranging from self-limiting gastroenteritis to typhoid fever. Previous results from our laboratory showed that Saccharomyces cerevisiae strain UFMG 905 isolated from ‘cachaça’ production presented probiotic properties due to its ability to protect against experimental infection with Salmonella enterica serovar Typhimurium. In this study, the effects of oral treatment with S. cerevisiae 905 were evaluated at the immunological level in a murine model of typhoid fever. Treatment with S. cerevisiae 905 inhibited weight loss and increased survival rate after Salmonella challenge. Immunological data demonstrated that S. cerevisiae 905 decreased levels of proinflammatory cytokines and modulated the activation of mitogen-activated protein kinases (p38 and JNK, but not ERK1/2), NF-κB and AP-1, signaling pathways which are involved in the transcriptional activation of proinflammatory mediators. Experiments in germ-free mice revealed that probiotic effects were due, at least in part, to the binding of Salmonella to the yeast. In conclusion, S. cerevisiae 905 acts as a potential new biotherapy against S. Typhimurium infection due to its ability to bind bacteria and modulate signaling pathways involved in the activation of inflammation in a murine model of typhoid fever

Effect of the trehalose levels on the screening of yeast as probiotic by in vivo and in vitro assays Efeito da trealose na seleção de leveduras para uso como probióticos utilizando testes in vitro e in vivo

Probiotics are viable defined microorganisms (bacteria or yeasts) that exert a beneficial effect on the health of the host when ingested in adequate amounts. Screening for such biotherapeutic agents is commonly performed by in vitro assays simulating gastrointestinal environment to determine the ability to survive in the digestive tract. In the present study, the possibility of extrapolation of data obtained in in vitro assays to in vivo conditions was studied using five Saccharomyces cerevisiae strains isolated from Brazilian Atlantic rain forest. Trehalose contents and survival after exposure to a combination of physiological stresses generally found in the gastrointestinal tract of humans were determined for the five yeasts and compared to the behavior of Saccharomyces boulardii, a well-known probiotic. The results were completed with the colonization capacity of the gastrointestinal tract of gnotobiotic mice by these yeast strains. Some results obtained by in vitro assays are not confirmed by in vivo experiments, indicating that the extrapolation cannot be always done.<br>Probióticos são definidos como microrganismos (bactérias e leveduras) que exercem um efeito benéfico na saúde do hospedeiro quando ingeridos em quantidades adequadas. A seleção desses agentes bioterapêuticos normalmente é feita por testes in vitro simulando o ambiente gastrointestinal que determina a capacidade de sobrevivência no trato digestivo. Neste trabalho, a possibilidade de extrapolação dos dados obtidos nos testes in vitro para as condições in vivo foi estudada utilizando cinco linhagens de Saccharomyces cerevisiae isoladas da floresta Atlântica brasileira. O conteúdo de trealose e a sobrevivência após a exposição a diversos estresses fisiológicos geralmente encontrados no trato gastrointestinal de humanos foram determinados para as cinco linhagens e os resultados comparados com a Saccharomyces boulardii, um probiótico conhecido. Esses resultados foram completados com a capacidade de colonização do trato gastrointestinal de camundongos gnotobióticos pelas leveduras. Pelos resultados obtidos, concluimos que os testes in vitro não são confirmados pelos ensaios in vivo, indicando que essa extrapolação não pode sempre ser feita

Protective effect of Lactobacillus delbrueckii subsp. Lactis CIDCA 133 in a model of 5 Fluorouracil-Induced intestinal mucositis

Mucositis is a cytotoxic side effect caused by chemotherapy drugs, such as 5-Fluorouracil (5-FU), being a serious clinical issue. Lactobacillus spp. could be a helpful strategy to alleviate 5-FU chemotherapy-caused intestinal damage, due to their ability to contribute to intestinal homeostasis through improvement of microbiota balance and immunomodulation. In this work we evaluated the effect of Lactobacillus delbrueckii subsp. lactis CIDCA 133 fermented milk in 5-FU-induced experimental mucositis. Intestinal histology, permeability and biochemical parameters showed that animals administrated with 5-FU and treated with CIDCA 133 fermented milk presented reduced intestinal IgA secretion and lower permeability in the small bowel. We showed that this strain preserves villus/crypt ratio, reduces the loss of goblet cells and inflammatory infiltration in ileum sections of 5-FU-treated animals. In conclusion, CIDCA 133 is able to prevent the intestinal mucosa damage caused by 5-FU revealing to be a promising strategy for intestinal mucositis treatment.Fil: De Jesus, Luís Cláudio Lima. Universidade Federal de Minas Gerais; BrasilFil: Martins Drumond, Mariana. Universidade Federal de Minas Gerais; BrasilFil: de Carvalho, André. Universidade Federal de Minas Gerais; BrasilFil: Santos, Spencer S.. Universidade Federal de Minas Gerais; BrasilFil: Martins, Flaviano S.. Universidade Federal de Minas Gerais; BrasilFil: Ferreira, Ênio. Universidade Federal de Minas Gerais; BrasilFil: Salgado Fernandes, Renata. Universidade Federal de Minas Gerais; BrasilFil: Branco de Barros, André Luís. Universidade Federal de Minas Gerais; BrasilFil: do Carmo, Fillipe Luis R. Universidade Federal de Minas Gerais; BrasilFil: Perez, Pablo Fernando. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Carvalho Azevedo, Vasco Ariston. Universidade Federal de Minas Gerais; BrasilFil: Mancha Agresti, Pamela. Universidade Federal de Minas Gerais; Brasi

NLRP6-associated host microbiota composition impacts in the intestinal barrier to systemic dissemination of Brucella abortus.

Brucella abortus is a Gram-negative bacterium responsible for a worldwide zoonotic infection-Brucellosis, which has been associated with high morbidity rate in humans and severe economic losses in infected livestock. The natural route of infection is through oral and nasal mucosa but the invasion process through host gut mucosa is yet to be understood. Studies have examined the role of NLRP6 (NOD-like receptor family pyrin domain-containing-6 protein) in gut homeostasis and defense against pathogens. Here, we investigated the impact of gut microbiota and NLRP6 in a murine model of Ba oral infection. Nlrp6-/- and wild-type (WT) mice were infected by oral gavage with Ba and tissues samples were collected at different time points. Our results suggest that Ba oral infection leads to significant alterations in gut microbiota. Moreover, Nlrp6-/- mice were more resistant to infection, with decreased CFU in the liver and reduction in gut permeability when compared to the control group. Fecal microbiota transplantation from WT and Nlrp6-/- into germ-free mice reflected the gut permeability phenotype from the donors. Additionally, depletion of gut microbiota by broad-spectrum-antibiotic treatment prevented Ba replication in WT while favoring bacterial growth in Nlrp6-/-. Finally, we observed higher eosinophils in the gut and leukocytes in the blood of infected Nlrp6-/- compared to WT-infected mice, which might be associated to the Nlrp6-/- resistance phenotype. Altogether, these results indicated that gut microbiota composition is the major factor involved in the initial stages of pathogen host replication and partially also by the resistance phenotype observed in Nlrp6 -/- mice regulating host inflammation against Ba infection