Neutropenic diets (ND) were developed to decrease gut-derived infections and are widely used. After finding that there were no clinical trials supporting their use, we discontinued ND in HSCT in late 2006. Our ND excluded fresh fruits and vegetables as well as black pepper, sushi, deli meats, raw milk products, soft cheeses, raw honey, miso, and yeast. It was replaced by a modified general diet (Non-ND) that permits black pepper, fresh fruits and vegetables, and homemade freshly squeezed juice - but excludes raw tomatoes. The other restrictions remain. 648 consecutive hospitalized patients were studied; 314 on ND and 314 after ND discontinuation (non-ND). All infections occurring during the first hospital stay were analyzed. All patients received ciprofloxacin 500 mg twice a day, fluconazole 200 mg daily (autograft) or voriconazole 200 mg twice daily (allograft), and acyclovir/valacyclovir. The documented infections included in the analysis comprised positive blood, urine (>100,000 organisms), BAL, stool, or wound cultures, and clostridium difficile. As the table shows, there were no differences between the ND and non-ND groups with regards to age, sex, diagnosis and conditioning regimen, or the number of days to resolution of neutropenia. There were no significant differences in the number of positive cultures between the groups during the neutropenic period. However, after the resolution of neutropenia, there was a significantly higher number of non-enteric gram-positive coccal infections in the ND group compared to non-ND. There was also a trend towards a higher incidence of C difficile, and a significantly higher incidence of new positive surveillance cultures of VRE on rectal swabs in the ND group.Tabled 1Neutropenic dietNon-neutropenic dietPAge (years)57 (18-76)56 (18-78)0.89Male:Female186:128190:1240.97Allogeneic:Autologous77:23772:2420.64Diagnosis0.91 Myeloma163165 NHL5764 AML5450 Other4039Conditioning regimen0.97 High-dose Melphalan163165 BEAM4542 Busulfan-fludarabine3233 Reduced-intensity3336 Median days to neutrophil recovery12120.91 Positive cultures during neutropenia97890.49 CoNS/MSSA/MRSA + miscellaneous gram-positive32331 C difficile24220.88 E faecium (VRE)991 Non-VRE Enterococci331 Gram-negative bacilli1590.21 S viridans11101 Fungus431 Positive cultures after resolution of neutropenia4820<0.001 CoNS/MSSA/MRSA + miscellaneous gram-positive2190.028 C difficile920.069 E faecium (VRE)730.34 Gram-negative bacilli840.38 S viridans211 Fungus111 VRE surveillance culture positivity acquired during hospitalization5631<0.004 Open table in a new tab Our findings show that there is no apparent benefit associated with ND. However, more surprising is the finding that some infections were more common with ND. It could be speculated that the microbial content of the non-ND is higher and, in the setting of broad-spectrum antimicrobial prophylaxis and therapy, such a diet could contribute to reduced colonization with virulent microorganisms. These findings suggest that additional studies are needed to investigate the role of dietary restrictions. If our findings are confirmed, a major change in an established but non-evidence-based practice will be needed. An added benefit of the more liberal diet would be greater palatability - which may contribute to reduction in the use of TPN and better nutrition.