This chapter presents an analysis of trust dynamics in mainstream news media outlets, ambient journalism, and digital platforms. Drawing from a neo institutionalist perspective and recovering its roots in phenomenological sociology, we hypothesized that digital platforms constitute an institution that is both object and base for different types of trust. The analysis relies on a survey administered in 2022 in four different countries: Germany, Italy, Norway, and the UK. The countries were chosen to represent different media systems in Europe. The results show that trust in digital platforms is positively correlated with trust in mainstream news media outlets in all four countries considered. In Italy and Germany, trust in platforms is also positively correlated with trust in ambient journalism. Results confirm our hypothesis that trust in digital platforms fosters different types of media trust, at least in Italy and Germany; then, acting both as object and base for trust. This result opens up reflections with respect to the role of trust in platforms in shaping the future of journalism and democracy dynamics.