title: Adhesion of bile-adapted Bifidobacterium strains to the HT29-MTX cell line is modified after sequential gastrointestinal challenge simulated in vitro using human gastric and duodenal juices.
abstract: According to the FAO/WHO, in vitro criteria for selection of probiotics for food application consist of testing survival when confronted with gastrointestinal tract (GIT) challenge and the ability to colonize the colon. We used a model that simulated GIT transit using sequential immersion in gastric and duodenal juices of human origin to evaluate survival of bile-adapted Bifidobacterium strains. Bifidobacterium animalis tolerated gastric juice, whereas Bifidobacterium longum showed poor survival under these conditions. In contrast, B. animalis strains were more sensitive to duodenal juice than B. longum. The percentage of survival after GIT transit simulation (GITTS), determined both by plate counts and fluorescent probes, was significantly higher for bile-adapted strains than for corresponding parental ones. This suggests that use of bile-adapted strains is a suitable approach for increasing survival of bifidobacteria under the harsh conditions of the upper GIT. However, the bile resistance phenotype was not related to improvement of adhesion capacity, after GITTS, of the intestinal cell line HT29-MTX which constitutively produces mucus. This work shows that sequential GITTS with human juices modified the in vitro adhesion properties of the strains challenged with colonocyte-like cells.
authors.affiliation: Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas, Carretera de Infiesto s/n, 33300 Villaviciosa, Asturias, Spain. greyes_gavilan@ipla.csic.es
authors.forename: Clara G
authors.initials: CG
authors.lastname: de los Reyes-Gavilán
authors.forename: Adolfo
authors.initials: A
authors.lastname: Suárez
authors.forename: María
authors.initials: M
authors.lastname: Fernández-García
authors.forename: Abelardo
authors.initials: A
authors.lastname: Margolles
authors.forename: Miguel
authors.initials: M
authors.lastname: Gueimonde
authors.forename: Patricia
authors.initials: P
authors.lastname: Ruas-Madiedo
mesh_terms: D000328:Adult; D000368:Aged; D001422:Bacterial Adhesion; D001644:Bifidobacterium / Q000502:physiology*; D001646:Bile / Q000378:metabolism*; D001826:Body Fluids / Q000378:metabolism; D004386:Duodenum / Q000378:metabolism*; D005260:Female; D005750:Gastric Juice / Q000378:metabolism*; D041981:Gastrointestinal Tract / Q000378:metabolism / Q000382:microbiology*; D019073:HT29 Cells; D006801:Humans; D008297:Male; D050296:Microbial Viability; D008875:Middle Aged