title: Saccharomyces boulardii modifies Salmonella typhimurium traffic and host immune responses along the intestinal tract.
abstract: 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.
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 4 "Inflammation, Cancer, Cancer Stem Cells" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Pontier-Bres
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 6 "Microbial toxins in host pathogen interactions" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Munro
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 6 "Microbial toxins in host pathogen interactions" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Boyer
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 8 "Hepatic complications in obesity" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Rodolphe
authors.initials: R
authors.lastname: Anty
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 4 "Inflammation, Cancer, Cancer Stem Cells" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Imbert
authors.affiliation: CRO2 INSERM U911, Campus Santé Timone, Université Aix-Marseille, Marseille, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Terciolo
authors.affiliation: CRO2 INSERM U911, Campus Santé Timone, Université Aix-Marseille, Marseille, France.
authors.forename: Fréderic
authors.initials: F
authors.lastname: André
authors.affiliation: Centre Scientifique de Monaco, Monaco, Monaco.
authors.forename: Patrick
authors.initials: P
authors.lastname: Rampal
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 6 "Microbial toxins in host pathogen interactions" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Lemichez
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 4 "Inflammation, Cancer, Cancer Stem Cells" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Peyron
authors.affiliation: INSERM, U1065, Centre Méditerranéen de Médecine Moléculaire (C3M), Team 4 "Inflammation, Cancer, Cancer Stem Cells" Nice, France; Université de Nice-Sophia Antipolis, UFR Médecine, IFR50, Faculté de Médecine, Nice, France.
authors.forename: Dorota
authors.initials: D
authors.lastname: Czerucka
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D005260:Female; D005786:Gene Expression Regulation; D054884:Host-Pathogen Interactions / Q000187:drug effects*; D007113:Immunity, Innate / Q000187:drug effects; D007371:Interferon-gamma / Q000235:genetics / Q000378:metabolism; D016753:Interleukin-10 / Q000235:genetics / Q000378:metabolism; D007422:Intestines / Q000276:immunology / Q000382:microbiology*; D008163:Luminescent Measurements; D008810:Mice, Inbred C57BL; D019936:Probiotics / Q000494:pharmacology*; D012440:Saccharomyces / Q000502:physiology*; D012486:Salmonella typhimurium / Q000276:immunology / Q000502:physiology*
chemical_list: D016753:Interleukin-10; D007371:Interferon-gamma