Fig. 3: The current regulatory changes for microbiome-based therapies.

In the European Union, medicinal products for human use are governed by the Directive 2001/83/EC. Biological medicinal products comprise several diverse product types, including blood and human plasma-derived medicinal products, immunological medicinal products (i.e. vaccines, toxins, serums and allergens) and Advanced therapy medicinal products (ATMPs). By their nature, microbiome-based medicinal products are considered as biological medicinal products but currently they do not have a “separate status” and are not referred to in any of the legislations. For some of these biological medicinal products, such as the blood and plasma-derived medicinal products, but also the ATMPs, the starting material can be tissues and cells from human origin. In this case, an additional piece of legislation is to be taken into account. For the EU, until August 2027, this additional piece of legislation consists of the blood directive (2002/98/EC) and the tissues and cells directive (2004/23/EC) (together designated as the BTC directives). In 2027, the regulation on standards of quality and safety for substances of human origin (SoHO) intended for human application (so called “SoHO Regulation”) will replace the BTC directives. The SoHO Regulation includes human microbiomes within the scope of this regulation, meaning that human microbiomes used as starting material for the production of microbiome-based medicinal products will have to follow the standards and requirements set by this new SoHO Regulation, in addition to the one set by the pharmaceutical legislation.