In this article, we question to what extent origin-food labels, namely Geographical Indications (GIs) and Slow Food Presidia, may effectively account for cultural biodiversity (CB). Building on Foucault's discourse theory, we question how the Slow Food movement and GI promoters have developed their own discourse and practice on CB, how these discourses contrast, and how they inform projects. Focusing on the practices to cultivate the microbiological life of three origin labeled cheeses (from France and Italy), we have revealed the gap between these institutional discourses and what happens on the ground. We argue that how actors' relationships in the marketplace unfold, from public authorities to the collectives of producers to consumers, may threaten the effects that these experiences of alternative food productions may have in the defense of biodiversity, causing, for instance, the loss of diversity of the invisible microbial ecosystems of artisan raw milk cheese. However, we conclude that, despite limitations, the mediatized institutional narrative on CB can amplify the political voice of local actors by fostering community and social relationships between the farmers.