title: Effect of bile acid on the cell membrane functionality of lactic acid bacteria for oral administration.
abstract: Lactic acid bacteria and other species dwelling in the gut must be tolerant to bile salts. This study sought to determine the effects of the bile salts taurodeoxycholate (TDCA) and deoxycholate (DCA) on Lactobacillus reuteri CRL 1098, a strain of likely probiotic value. When compared to other lactobacilli, L. reuteri showed the highest survival rate but remained sensitive to high (>3 mM) DCA concentrations. DCA produced complete permeabilization of cells, abolished glucose uptake and severely distorted the cell envelope, as shown by electron microscopy. Detailed analytical studies revealed a change in the phospholipid to glycolipid ratio, and also in lipid proportions. The C18:1 W9C form remarkably increased, possibly following a rapid adaptive response during DCA treatment. This study provides the first solid evidence of the mechanism of DCA toxicity in a lactic acid bacterium.
authors.affiliation: Centro de Referencia para Lactobacilos (CERELA), CONICET, Chacabuco 145, San Miguel de Tucumán, T4000ILC, Tucumán, Argentina. ptaranto@cerela.org.ar <ptaranto@cerela.org.ar>
authors.forename: María Pía
authors.initials: MP
authors.lastname: Taranto
authors.forename: Gaspar
authors.initials: G
authors.lastname: Perez-Martinez
authors.forename: Graciela
authors.initials: G
authors.lastname: Font de Valdez
mesh_terms: D002462:Cell Membrane / Q000187:drug effects* / Q000648:ultrastructure; D002463:Cell Membrane Permeability / Q000187:drug effects; D003840:Deoxycholic Acid / Q000494:pharmacology*; D005947:Glucose / Q000378:metabolism; D006017:Glycolipids / Q000032:analysis; D007778:Lactobacillus / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D052200:Limosilactobacillus reuteri / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D008563:Membrane Lipids / Q000032:analysis; D050296:Microbial Viability / Q000187:drug effects; D046529:Microscopy, Electron, Transmission; D010743:Phospholipids / Q000032:analysis; D013657:Taurodeoxycholic Acid / Q000494:pharmacology*
chemical_list: D006017:Glycolipids; D008563:Membrane Lipids; D010743:Phospholipids; D003840:Deoxycholic Acid; D013657:Taurodeoxycholic Acid; D005947:Glucose