Toward the development of defined microbial therapeutics

Abstract The collection of micro-organisms living in the mammalian gastrointestinal tract, termed the gut microbiota, has been shown to have profound impacts on host health and increasingly is regarded as a viable therapeutic target. Clinical studies of fecal microbiota transplantation have demonstrated potential efficacy of microbiota-based therapies for diseases including Clostridioides difficile infections, inflammatory bowel disease, graft-versus-host disease and cancer. However, the lack of understanding of the active ingredients and potential risks of such therapies pose challenges for clinical application. Meanwhile, efforts are being made to identify effector microbes directly associated with a given phenotype, to establish causality and to devise well-characterized microbial therapeutics for clinical use. Strategies based on defined microbial components will likely enhance the potential of microbiota-targeted therapies.