The completion of the Human Microbiome Project in 2012 created a blueprint of what a balanced microbial ecol. looks like and a roster of the organisms that call the human body home.Several startup companies began working on packaging microbes as oral medicines to treat diseases and disorders ranging from irritable bowel syndrome to epilepsy and diabetes, all of which have been linked to imbalances in gut microbes.So far, some of the best success in microbial manipulation has been with FMTs to treat Clostridium difficile infection.FMT is still an investigational therapy for any disease, with the FDA still figuring out how to regulate this form of probiotic.Early transplants were unprocessed, homogenized stool delivered either via an enema or endoscope.In a newer version of FMT, the microbiota portion of the stool is separated out, packaged and swallowed as a pill.Treating cancer is the next frontier for probiotics and FMT.The idea is to partner gut microbes with checkpoint inhibitors to improve the efficacy of the latter.Wargo, along with the Parker Institute for Cancer Immunotherapy in California, is working with Cambridge, Massachusetts-based Seres Therapeutics to test an orally delivered cocktail of bacterial spores, SER-401, in a clin. trial.Wargo′s profiling of the gut microbial composition of patients has, in part, guided the species chosen to be included in SER-401.According to Wargo, the metastatic melanoma trial will randomize patients, all of whom will receive anti-PD-1 therapy, to one of three treatment arms: treatment with SER-401, placebo, or an FMT, either from a healthy donor with a favorable microbiota or from a cancer patient whose tumors all shrank following the same anti-PD1 therapy.Seres is sourcing its spore forming bacteria from the stools of heavily prescreened, healthy individuals."We believe that this is an issue of ecol. and that, to have an influence, we need to deliver a consortia of microorganisms," says David Cook, Seres chief scientific officer.The trial is slated to start later this year.In another trial planned to begin this year, Gajewski has partnered with Cambridge-based Evelo Biosciences to test whether a pill containing a freeze-dried single Bifidobacterium strain can improve the efficacy of a checkpoint blockade antibody.The approach builds off of the fact that he not only saw a benefit of Bifidobacterium in mice with melanoma tumors, but also that his group has found a higher abundance of Bifidobacterium in cancer patients correlated with a better response to immunotherapy.Zitvogel is also working on encapsulating bacteria to deliver to cancer patients receiving checkpoint inhibitors and is the cofounder of a biotech called EverImmune, but she has yet to disclose specifics or a trial plan.Meanwhile, other startups are also working on concentrated, bacteria-filled pills.Cambridge, Massachusetts-based Vedanta Biosciences plans to start a first-in-human trial in 2019 to treat cancer using lab-grown bacterial strains originally identified in the gut of healthy individuals."The gut microbiota has an important role in infectious disease.I think the next frontier is the gut microbiota in cancer, autoimmune and allergy disorders," says Bernat Olle, Vedanta′s CEO.