Fig. 1: Microbiome-based therapies spectrum.

Microbiome-based therapies represent a large and diverse range of innovations and can be viewed as a continuum, ranging from microbiota transplantation (on the left), whole ecosystem-based medicinal products, rationally-designed microbial ecosystems (co-culture of various strains for their synergistic activities) all the way to live biotherapeutic products (LBPs – Single strains or mixtures of multiple strains), non-living biotherapeutic products or phage therapies (on the right). For the therapies on the left of the spectrum such as microbiota transplantation and whole ecosystem-based medicinal products, the donor/origin of the microbiome sample has a major importance in the determination of the benefit/risk ratio as these therapies are only partly characterized and controlled. However, when moving to the right of the spectrum, the impact of donor/origin of the microbiome sample on the benefit/risk ratio decreases while the degree of characterization and control of the products themselves increases.