Saccharomyces boulardii modifies Salmonella typhimurium traffic and host immune responses along the intestinal tract

• Published in: PloS one 2014-08, Vol.9 (8), p.e103069
• Main Authors: Pontier-Bres, Rodolphe, Munro, Patrick, Boyer, Laurent, Anty, Rodolphe, Imbert, Véronique, Terciolo, Chloé, André, Fréderic, Rampal, Patrick, Lemichez, Emmanuel, Peyron, Jean-François, Czerucka, Dorota
• Format: Article
• Language: English
• Subjects: Animals; Antibacterial agents; Bacteria; Bacterial Adhesion; Biology and Life Sciences; Body weight loss; Cancer; Cecum; Colon; Cytokines; Dendritic cells; Development and progression; Diarrhea; E coli; Emission measurements; Epithelium; Escherichia coli; Female; Gastrointestinal system; Gastrointestinal tract; Gene expression; Gene Expression Regulation; Health aspects; Host-Pathogen Interactions - drug effects; Immune response; Immune system; Immunity, Innate - drug effects; Infection; Infections; Infectious diseases; Inflammation; Ingestion; Innate immunity; Interferon-gamma - genetics; Interferon-gamma - metabolism; Interleukin 10; Interleukin-10 - genetics; Interleukin-10 - metabolism; Intestine; Intestines - immunology; Intestines - microbiology; Liver; Luminescent Measurements; Medicine and Health Sciences; Mice; Mice, Inbred C57BL; Microbiota; Migration; Organs; Pathogenesis; Pathogens; Photonics; Photorhabdus; Probiotics; Probiotics - pharmacology; Prophylaxis; Research and Analysis Methods; RNA; Rodents; Saccharomyces; Saccharomyces - physiology; Salmonella; Salmonella enterica; Salmonella Typhimurium; Salmonella typhimurium - immunology; Salmonella typhimurium - physiology; Shigella; Small intestine; Spleen; Stem cells; Stomach; Streptomycin; Translocation; Tropical diseases; Yeast; Yeasts; γ-Interferon
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0103069

Salmonella enterica serovar Typhimurium (ST) is an enteropathogenic Gram-negative bacterium that causes infection following oral ingestion. ST spreads rapidly along the gastrointestinal tract (GIT) and invades the intestinal epithelium to ultimately reach internal body organs. The probiotic yeast Saccharomyces boulardii BIOCODEX (S.b-B) is prescribed for prophylaxis of diarrheal infectious diseases. We previously showed that S.b-B prevents weight loss in ST-infected mice and significantly decreases bacterial translocation to the spleen and liver. This study was designed to investigate the effect of S.b-B on ST migration along the GIT and the impact of the yeast on the host's early innate immune responses. Bioluminescent imaging (BLI) was used to evaluate the effect of S.b-B on the progression of luminescent Salmonella Typhimurium (ST-lux) in the GIT of mice pretreated with streptomycin. Photonic emission (PE) was measured in GIT extracts (stomach, small intestine, cecum and colon) at various time periods post-infection (PI). PE analysis revealed that, 45 min PI, ST-lux had migrated slightly faster in the mice treated with S.b-B than in the untreated infected animals. At 90 min PI, ST-lux had reached the cecum in both groups of mice. Adhesion of ST to S.b-B was visualized in the intestines of the mice and probably accounts for (1) the faster elimination of ST-lux in the feces, and (2) reduced translocation of ST to the spleen and liver. In the early phase of infection, S.b-B also modifies the host's immune responses by (1) increasing IFN-γ gene expression and decreasing IL-10 gene expression in the small intestine, and (2) elevating both IFN-γ, and IL-10 mRNA levels in the cecum. BLI revealed that S.b-B modifies ST migration and the host immune response along the GIT. Study findings shed new light on the protective mechanisms of S.b-B during the early phase of Salmonella pathogenesis.