Hematopoietic cell transplant (HCT) is one of the most complex procedures in medicine. Since its inception several decades ago, it has been continuously refined and is now a standard procedure for many hematologic malignancies and some nonmalignant diseases. However, despite these advances, relapse of the underlying disease, graft-versus-host disease (GVHD), organ toxicities, and infectious complications continue to be major obstacles to success. Inherent to the HCT procedure is a profound posttransplantation immunodeficiency, which increases the risk of serious and often fatal infectious complications. Infections can originate from exogenous acquisition of pathogens or reactivation from latency. Once infected, the patient may develop progressive and often fatal disease. Infections have also been implicated in the development of GVHD. To minimize exposure from food-borne pathogens, most cancer centers recommend a restricted diet. This diet, also referred to as the ‘‘neutropenic diet’’, is usually recommended throughout the period of immunosuppression with the goal to minimize invasive infections originating from food-derived pathogens and, in the allogeneic transplantation setting, also to potentially minimize GVHD. The practice to recommend this diet is endorsed by evidence-based guidelines; however, the quality of the evidence is generally weak mostly category III (ie, based on expert opinion) [1,2]. In fact, although there are theoretical arguments as well as preclinical nonhuman studies and clinical results from the early days of HCT [3] to support the concept, the strategy as a whole has never been evaluated and proven to be