title: In vitro characterization of the digestive stress response and immunomodulatory properties of microorganisms isolated from smear-ripened cheese.
abstract: Thirty-six microorganisms (twenty-one bacteria, twelve yeasts and three fungi) were isolated from surface-ripened cheeses and subjected to in vitro digestive stress. The approach mimicked gastric and/or duodenal digestion. Lactobacillus rhamnosus GG, Escherichia coli Nissle 1917 and Saccharomyces boulardii were used as reference strains. We studied the microorganisms grown separately in culture medium and then included (or not) in a rennet gel. The microorganisms' immunomodulatory abilities were also assessed by profiling cytokine induction in human peripheral blood mononuclear cells (PBMCs). The loss of viability was less than 1 log CFU/mL for yeasts under all conditions. In contrast, Gram-negative bacteria survived gastric and/or duodenal stress well but most of the Gram-positive bacteria were more sensitive (especially to gastric stress). Inclusion of sensitive Gram-positive bacteria in rennet gel dramatically improved gastric survival, when compared with a non-included cultured (with a 4 log CFU/mL change in survival). However, the rennet gel did not protect the bacteria against duodenal stress. The PBMC cytokine assay tests showed that the response to yeasts was usually anti-inflammatory, whereas the response to bacteria varied from one strain to another.
authors.affiliation: AgroParisTech, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850, Thiverval Grignon, France; INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850, Thiverval Grignon, France. Electronic address: nadege.adouard@grignon.inra.fr.
authors.forename: Nadège
authors.initials: N
authors.lastname: Adouard
authors.affiliation: Institut Pasteur de Lille, Lactic acid Bacteria & Mucosal Immunity, Center for Infection and Immunity of Lille UMR 8204, 1, rue du Pr Calmette, BP 245, F-59019 Lille, France. Electronic address: benoit.foligne@ibl.cnrs.fr.
authors.forename: Benoît
authors.initials: B
authors.lastname: Foligné
authors.affiliation: Institut Pasteur de Lille, Lactic acid Bacteria & Mucosal Immunity, Center for Infection and Immunity of Lille UMR 8204, 1, rue du Pr Calmette, BP 245, F-59019 Lille, France.
authors.forename: Joëlle
authors.initials: J
authors.lastname: Dewulf
authors.affiliation: AgroParisTech, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850, Thiverval Grignon, France. Electronic address: marielle.bouix@agroparistech.com.
authors.forename: Marielle
authors.initials: M
authors.lastname: Bouix
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850, Thiverval Grignon, France. Electronic address: picque@grignon.inra.fr.
authors.forename: Daniel
authors.initials: D
authors.lastname: Picque
authors.affiliation: INRA, Centre de Biotechnologies Agroindustrielles, AgroParisTech INRA, UMR 782 Genie & Microbiologie des Procedes Alimentaires, F-78850, Thiverval Grignon, France. Electronic address: pascal.bonnarme@grignon.inra.fr.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bonnarme
mesh_terms: D002478:Cells, Cultured; D002611:Cheese / Q000382:microbiology*; D004063:Digestion; D005658:Fungi / Q000302:isolation & purification / Q000502:physiology*; D006090:Gram-Negative Bacteria / Q000302:isolation & purification / Q000502:physiology*; D006094:Gram-Positive Bacteria / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000276:immunology* / Q000382:microbiology*; D050296:Microbial Viability; D015003:Yeasts / Q000302:isolation & purification / Q000502:physiology
keywords: Digestive stress; Immunomodulation; In vitro digestive model; Peripheral blood mononuclear cell; Smear-ripened cheese microbiota