"For the first time transplanting gut bacteria from healthy donors was used to successfully treat patients suffering from severe colitis caused by treatment with immune checkpoint inhibitors https ICIs. The study from The University of Texas MD Anderson Cancer Center http which includes two patients suggests fecal microbiota transplantation FMT is worth investigating in clinical trials as a therapy for this common side effect of immunotherapy https The research led by Yinghong Wang M.D. Ph.D. httpsfaculty.mdanderson.orgprofilesyinghong_wang.html assistant professor of Gastroenterology Hepatology  Nutrition https and director of Medication Induced Colitis and Enteritis was published today in Nature Medicine httpdx.doi.org.s. The resolution of colitis in these patients can be confirmed clinically and endoscopically after FMT treatment said Wang. Based on these results this should be evaluated even as a firstline therapy for ICIassociated colitis because its safe quick and the effect is durable  from one treatment. Immune checkpoint inhibitors which release a block on the immune system to attack cancer have been successful in providing durable responses for patients with several cancer types. However these treatments are often associated with significant immunerelated toxicities. Colitis inflammation of the colon is the second most common side effect from ICIs occurring in up to  percent of patients explained Wang. When ICIassociated colitis is severe guidelines require a patient to stop ICI treatment until the colitis is in remission. If the patient is a good responder to immunotherapy that means youve taken their effective treatment away said Wang. We have a limited amount of time to fix the problem so they can resume ICI treatment but I feel that weve made great progress in this area. The researchers chose to investigate the potential for FMT as an alternative compassionateuse therapy for patients suffering from refractory or unresponsive ICIassociated colitis. The two patients included in the study were treated at MD Anderson between June  and January . FMT has shown promise in treating other types of gastrointestinal diseases such as recurrent Clostridium difficile infection and inflammatory bowel disease IBD which shares many clinical and molecular characteristics with ICIassociated colitis. These conditions typically are treated with steroids and targeted immunosuppressive agents which result in additional severe side effects and can counteract the effects of immunotherapy. Both patients in the study had a complete resolution of their colitis following treatment with FMT. The first patients colitis resolved within two weeks following a single FMT treatment the second patient experienced a partial recovery after the first treatment followed by complete recovery after a second FMT. With endoscopic evaluation before and after treatment both patients displayed significant improvements in inflammation and ulcerations including a reduction of inflammatory immune cells. Pre and posttreatment stool analyses revealed patients gut microbiomes to be most similar to the donor immediately after treatment with less resemblance to the donor over time. Still posttreatment gut bacteria remained distinct from their own pretreatment microbiome. Additionally distinct new populations of bacterial species were evident in these patients following FMT compared to pretreatment samples including several species known to be protective or reduce inflammation. The authors acknowledge significant limitations to this study based on the very small cohort and they plan to pursue clinical trials to investigate the effectiveness of FMT in treating ICIassociated colitis as compared with standard immunosuppressive therapy. FMT continues to be offered to MD Anderson patients on a compassionateuse basis. Previous MD Anderson research https showed that bacteria in the gut influence patient response to ICI therapy and other evidence suggests modifying the microbiome in mice can alter their response to immunotherapy. The current data further suggests there is the potential for many molecular studies to better understand the role of the microbiome in driving ICIcolitis and immunotherapy response more broadly. The study was supported by the Andrew Sabin Family Fellowship Program the American Association for Cancer Research  Stand Up to Cancer the National Institutes of Health CAA HL the Cancer Prevention  Research Institute of Texas and the Melanoma Moon Shot https part of MD Andersons Moon Shots Program https a collaborative effort to accelerate the development of scientific discoveries into clinical advances that save patients lives In addition to Wang other MD Anderson authors include Diana Wiesnoski Christopher Sanchez and ChiaChi Chang Ph.D. all of Genomic Medicine Beth Helmink M.D. Ph.D. and Vancheswaran Gopalakrishnan Ph.D. both of Surgical Oncology Hamzah AbuSbeih M.D. Gottumukkala Raju M.D. and John Stroehlein M.D. all of Gastroenterology Hepatology  Nutrition Edwin Parra M.D. Ph.D. and Alejandro FranciscoCruz Ph.D. both of Translational Molecular Pathology Matthew Campbell M.D. Jianjun Gao M.D. Ph.D. and Sumit Subudhi M.D. Ph.D. all of Genitourinary Medical Oncology Dipen Maru M.D. of Pathology Jorge Blando DVM and James Allison Ph.D. both of Immunology Padmanee Sharma M.D. Ph.D. of Genitourinary Medical Oncology and Immunology Michael Tetzlaff M.D. Ph.D. of Translational Molecular Pathology and Pathology Jennifer Wargo M.D. of Genomic Medicine and Surgical Oncology and Robert Jenq M.D. of Genomic Medicine and Stem Cell Transplantation. Additional authors include Kati Choi M.D. Baylor College of Medicine Houston Hebert DuPont M.D. UTHealth School of Public Health and Kelsey Research Foundation Houston and ZhiDong Jiang Dr.Ph. UTHealth School of Public Health Houston."