title: Adaptation and response of Bifidobacterium animalis subsp. lactis to bile: a proteomic and physiological approach.
abstract: Bile salts are natural detergents that facilitate the digestion and absorption of the hydrophobic components of the diet. However, their amphiphilic nature makes them very inhibitory for bacteria and strongly influences bacterial survival in the gastrointestinal tract. Adaptation to and tolerance of bile stress is therefore crucial for the persistence of bacteria in the human colonic niche. Bifidobacterium animalis subsp. lactis, a probiotic bacterium with documented health benefits, is applied largely in fermented dairy products. In this study, the effect of bile salts on proteomes of B. animalis subsp. lactis IPLA 4549 and its bile-resistant derivative B. animalis subsp. lactis 4549dOx was analyzed, leading to the identification of proteins which may represent the targets of bile salt response and adaptation in B. animalis subsp. lactis. The comparison of the wild-type and the bile-resistant strain responses allowed us to hypothesize about the resistance mechanisms acquired by the derivative resistant strain and about the bile salt response in B. animalis subsp. lactis. In addition, significant differences in the levels of metabolic end products of the bifid shunt and in the redox status of the cells were also detected, which correlate with some differences observed between the proteomes. These results indicate that adaptation and response to bile in B. animalis subsp. lactis involve several physiological mechanisms that are jointly dedicated to reduce the deleterious impact of bile on the cell's physiology.
authors.affiliation: Unité Flore Lactique et Environnement Carné (UR309), INRA, Domaine de Vilvert, F-78350 Jouy-en-Josas, France.
authors.forename: Borja
authors.initials: B
authors.lastname: Sánchez
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Champomier-Vergès
authors.forename: Birgitte
authors.initials: B
authors.lastname: Stuer-Lauridsen
authors.forename: Patricia
authors.initials: P
authors.lastname: Ruas-Madiedo
authors.forename: Patricia
authors.initials: P
authors.lastname: Anglade
authors.forename: Fabienne
authors.initials: F
authors.lastname: Baraige
authors.forename: Clara G
authors.initials: CG
authors.lastname: de los Reyes-Gavilán
authors.forename: Eric
authors.initials: E
authors.lastname: Johansen
authors.forename: Monique
authors.initials: M
authors.lastname: Zagorec
authors.forename: Abelardo
authors.initials: A
authors.lastname: Margolles
mesh_terms: D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D001644:Bifidobacterium / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology*; D001646:Bile / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D020543:Proteome / Q000187:drug effects*; D040901:Proteomics