title: Response of lactic acid bacteria to the digestive environment.
abstract: BACKGROUND
  This article reviews several studies regarding adaptation to the digestive environment by lactic acid bacteria. The behavior of lactic acid bacteria in the digestive tract is worth investigating, and bacterial physiologic changes remain to be examined.
  
  
  METHODS
  A genetic approach based on the fusion of bacterial promoters with genes of the reporter protein luciferase is described to screen for functions that lactic acid bacteria may suppress or activate in the digestive environment.
  
  
  RESULTS
  Variations in luciferase expression from different promoters were observed in the digestive tract of mice models. In some cases, the promoter could be activated in response to an inducer provided with the diet.
  
  
  CONCLUSIONS
  These data suggest that lactic acid bacteria are metabolically active in the digestive tract and can synthesize proteins to adapt to the digestive environment.
authors.affiliation: Unité d'écologie et de Physiologie du Système Digestif, Institut National de la Recherche Agronomique, Jouy-en-Josas, France.
authors.forename: Denis D G
authors.initials: DD
authors.lastname: Mater
authors.forename: Gerard
authors.initials: G
authors.lastname: Corthier
mesh_terms: D000818:Animals; D004064:Digestive System / Q000382:microbiology*; D005772:Gastrointestinal Transit / Q000502:physiology*; D017930:Genes, Reporter; D007778:Lactobacillus / Q000378:metabolism / Q000502:physiology*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice / Q000382:microbiology*
chemical_list: D008164:Luminescent Proteins; D008156:Luciferases