title: Glutathione-enriched baker's yeast: production, bioaccessibility and intestinal transport assays.
abstract: OBJECTIVE
  A glutathione (GSH) yeast-based biomass (Saccharomyces cerevisiae) was used to investigate GSH stability, solubilization during gastrointestinal digestion and GSH intestinal transport.
  
  
  RESULTS
  A postgrowing procedure was applied to improve intracellular GSH yeast content. The presence of adenine (ADE) in the biotransformation solution (CYS-GLY-GLU mixture) and alternatively, a glucose shot after 4-h incubation, allowed to obtain cells containing about GSH 1.6-1.7% dcw (dry cell weight) (control 0.5%). Yeast samples were subjected to in vitro gastrointestinal digestion and absorption assays employing Caco-2 and HT29-MTX cell lines in different proportions (100/0, 70/30 and 50/50). Trials were also performed to verify intestinal cell viability.
  
  
  CONCLUSIONS
  At least 87% of ingested GSH is available in reduced form for intestinal absorption. In vitro GSH transport assays indicated that GSH is poorly absorbed (<20%). Nevertheless, studies in response to oxidative stress induced by H2 O2 demonstrated a protective role of the GSH-enriched biomass towards intestinal cell viability.
  
  
  CONCLUSIONS
  An enriched GSH yeast-based biomass has been obtained using a postgrowing procedure. Although GSH present in enriched yeasts is poorly absorbed by intestinal cells, this biomass showed an intestinal local protective effect, improving cells viability when a simulated oxidative stress was applied.
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milano, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Musatti
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Devesa
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Calatayud
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (IATA-CSIC), Paterna, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Vélez
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Manzoni
authors.affiliation: Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Rollini
mesh_terms: D001682:Biological Availability; D001692:Biological Transport; D001711:Biotransformation; D018938:Caco-2 Cells; D002470:Cell Survival; D018920:Coculture Techniques; D004063:Digestion; D004151:Dipeptides / Q000378:metabolism; D005612:Freeze Drying; D005978:Glutathione / Q000378:metabolism* / Q000493:pharmacokinetics; D019073:HT29 Cells; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D007422:Intestines / Q000166:cytology; D018384:Oxidative Stress; D010539:Permeability; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D015002:Yeast, Dried / Q000378:metabolism*
chemical_list: D004151:Dipeptides; C028505:cysteinylglycine; D005978:Glutathione
keywords: Caco-2; HT29-MTX; gastrointestinal digestion; glutathione; intestinal absorption; yeast