Abstract. In the search for new substitutes to the use of sulfur dioxide (SO 2 ) in oenology, a new line of research based on nanotechnology has been launched. Within this line, this paper evaluates the suitability of two new biocompatible silver nanoparticles (Ag-NPs) to control microbial growth in wine as well as their stability and potential risks at intestinal level. Antimicrobial activities against spoilage wine microorganisms were carried out in both culture media and wines. In addition, in vitro simulations (static and dynamic) were conducted to monitor the passage of Ag-NPs through the buco-gastrointestinal tract and also to assess their effects on the gut microbiota and intestinal epithelial cells. Both Ag-NPs proved to be highly efficient for the control of wine undesirable bacteria in culture media and microvinification assays, and to a lesser extent, for reducing Brettanomyces populations in wine. Furthermore, undigested Ag-NPs as their corresponding digests after gastrointestinal simulation were not toxic to intestinal microbiota either epithelial cells, at least at the conditions used in these experiments.