Saccharomyces cerevisiae strain 905 reduces the translocation of Salmonella enterica serotype Typhimurium and stimulates the immune system in gnotobiotic and conventional mice

Abstract

Previous results in the laboratory of the authors showed that Saccharomyces cerevisiae strain 905, isolated during 'cachaç a' production, was able to colonize and survive in the gastrointestinal tract of germ-free and conventional mice, and to protect these animals against oral challenge with Salmonella enterica serotype Typhimurium or Clostridium difficile. In the present work, the effects of S. cerevisiae 905 on the translocation of Salm. Typhimurium (mesenteric lymph nodes, Peyer's patches, spleen, liver) as well as on the immune system (number of Kü pffer cells, immunoglobulin production, clearance of Escherichia coli B 41 ) were evaluated in gnotobiotic and/or conventional mice. The treatment with the yeast reduced significantly the translocation of Salm. Typhimurium to liver in gnotobiotic animals and to all the organs tested in conventional mice. The number of Kü pffer cells per 100 hepatocytes in liver was significantly higher (P<0.05) in yeast mono-associated mice (52.9±15.7) than in germ-free controls (38.1±9.0). Probably as a consequence, clearance of E. coli B 41 from the bloodstream was more efficient in yeast mono-associated animals when compared to germ-free mice. Higher levels (P<0.05) of secretory IgA in intestinal content and of IgA and IgM in serum were observed in yeast mono-associated mice when compared to germ-free group. Concluding, the protection against pathogenic bacteria observed in a previous study was probably due to a modulation of both local and systemic immunity of mice treated with S. cerevisiae 905. INTRODUCTIONProbiotics are defined as live micro-organisms that when administered in adequate amounts confer a health benefit to the host (Food and Agriculture Organization of the United Nations & World Health Organization, 2002). These microorganisms are widely used in pharmaceutical preparations and fermented dairy products. Lactobacilli and Bifidobacteria are typically found in probiotic products for humans, as well as some yeasts such as Saccharomyces boulardii.S. boulardii, a non-pathogenic yeast, was isolated from lychee fruit in Indochina and grows at the unusually high temperature of 37 uC (McFarland & Bernasconi, 1993). It has been used for the treatment of different types of diarrhoeal diseases, such as antibiotic-associated diarrhoea (Bartlett, 1992;McFarland et al., 1995;Surawicz, 2003), Clostridium difficile-associated intestinal disease (Elmer et al., 1999;Surawicz et al., 2000;Surawicz, 2003), traveller's diarrhoea (Scarpignato & Rampal, 1995) and diarrhoea in HIV-infected patients (Born et al., 1993).Many mechanisms of action have been proposed to explain S. boulardii protection and they have been summarized by et al., 2004). This leads to the question whether other strains of Saccharomyces, as well as S. boulardii, possess biotherapeutic properties. Brazil is well known for its rich biodiversity in terms of animal, vegetal and microbial species, and yeast with probiotic properties certainly could be screened from Brazilian environmental and agroindustrial sources. ...

Effect of the trehalose levels on the screening of yeast as probiotic by in vivo and in vitro assays

“…Other Saccharomyces spp. or members of other yeast genera may have probiotic activity similar to that of S. boulardii or even better, as already demonstrated by Martins et al (14,15) in mice models. The objective of this work was to determine whether higher trehalose levels or the capacity to produce large amounts of this sugar were advantageous to microbial survival in in vitro experiments simulating different stress conditions commonly present in the bile salts.…”

Probiotic Saccharomyces cerevisiae strains as biotherapeutic tools: is there room for improvement?

“…Treated mice also had a lower mortality rate than naïve controls challenged with S. Typhimurium (Martins et al 2005;Martins et al 2011). S. cerevisiae UFMG A-905 have shown adhesion to some enteropathogenic bacteria, such as E. coli, S. Typhi, and S. Typhimurium (Tiago et al 2012), neutralizing the translocation of the latter from the GIT to the liver, spleen, and mesenteric lymph nodes (Martins et al 2007). This probiotic yeast increased the production of IL-10 and sIgA in healthy mice (Martins et al 2007;Generoso et al 2010).…”

“…S. cerevisiae UFMG A-905 have shown adhesion to some enteropathogenic bacteria, such as E. coli, S. Typhi, and S. Typhimurium (Tiago et al 2012), neutralizing the translocation of the latter from the GIT to the liver, spleen, and mesenteric lymph nodes (Martins et al 2007). This probiotic yeast increased the production of IL-10 and sIgA in healthy mice (Martins et al 2007;Generoso et al 2010). In a mouse typhoid fever model, S. cerevisiae UFMG A-905 reduced both inflammation and IL-6, TNF-α, IFN-γ, and IL-10 levels, due to modulation of signaling pathways responsible for the expression of many inflammatory cytokines, such as NF-κB, AP-1, and MAPK pathways (Martins et al 2011).…”

Adhesion to the yeast cell surface as a mechanism for trapping pathogenic bacteria by Saccharomyces probiotics

“…We demonstrated previously that Saccharomyces cerevisiae strain UFMG 905 has potential as a probiotic due to its ability to protect mice against Salmonella enterica serovar Typhimurium and Clostridium difficile infection in a murine model (Martins et al, 2005), and to inhibit bacterial translocation and modulate both local and systemic immunity of mice (Martins et al, 2007;Generoso et al, 2010). Recent immunological data demonstrated that both Saccharomyces boulardii and Saccharomyces cerevisiae UFMG 905 decreased the levels of pro-inflammatory cytokines and modulated the activation of mitogenactivated protein kinases (p38 and JNK, but not ERK1/2), NF-kB and AP-1 signalling pathways, which are involved in the transcriptional activation of pro-inflammatory mediators induced by Salmonella infection (Martins et al, , 2011.…”