Potential modalities for gut microbiome manipulation include diet, probiotics, prebiotics, synbiotics, and fecal microbiota transplantation. Probiotics are live microorganisms that, when administered, confer a health benefit to the host. Prebiotics are non-digestible substrates that can be selectively utilized by host microorganisms. Synbiotics are products that contain both prebiotics and probiotics. Fecal microbiota transplantation (FMT) is the administration of fecal matter from a donor to a recipient. Examples of each based on existing or planned studies are provided.