Associations between the composition of the intestinal microbiome and many human diseases, including inflammatory bowel disease, cardiovascular disease, metabolic disorders, and cancer, have been elegantly described in the past decade. Now, whole-genome sequencing, bioinformatics, and precision gene-editing techniques are being combined with centuries-old therapies, such as fecal microbiota transplantation, to translate current research into new diagnostics and therapeutics to treat complex diseases. Bugs as Drugs provides a much-needed overview of microbes in therapies and will serve as an excellent resource for scientists and clinicians as they carry out research and clinical studies on investigating the roles the microbiota plays in health and disease. In Bugs as Drugs, editors Robert A. Britton and Patrice D. Cani have assembled a fascinating collection of reviews that chart the history, current efforts, and future prospects of using microorganisms to fight disease and improve health. Sections cover traditional uses of probiotics, next-generation microbial therapeutics, controlling infectious diseases, and indirect strategies for manipulating the host microbiome.