Who has the guts to make health claims? Good and Bad Scientists in Europe

How can scientific statements be made in which molecules or bacterial strains figure as active food constituents, contributing to human health beyond basic nutrition? This paper traces the specific historical and political circumstances that gave rise to the above question, and how the issue is played out in the EU at present. Special attention goes to the European health claims regulation that is in the course of being implemented today. Often referred to as a 'learning process', this implementation has proven to be very difficult and sometimes conflictual, especially regarding claims related to the human intestinal flora. Here, the nature of scientific evidence and the boundary between food and medicine have become the stakes in discussions and contestations between the European Food Safety Authority (EFSA), new emerging groups such as 'gut health' scientists, and scattered critical voices throughout the Member States. Next to a subject of actual research, the 'gut' becomes a space of symbolic investment where 'good' and 'bad' bacteria echo the rivaling conceptions of good and bad science between the actors involved in the production and evaluation of health claims. It will be shown that in addition to the rise of new professional identities, these frictions are also changing the meanings of 'nutrition' and the clinical trial.