The increased infection rate in patients on a liberalized diet was specifically driven by a twofold increase in organisms originating from the GI tract. This provides a strong mechanistic link, suggesting the diet introduces pathogens that translocate through the gut barrier compromised by chemotherapy or transplant.
In a multivariable analysis, the single most important risk factor for infection was the duration of neutropenia. The infection rates between the liberalized and neutropenic diet groups only began to diverge after two weeks, suggesting the diet's risk is most pronounced in patients with prolonged immunosuppression.
Contrary to expectations, a trial found that allowing fresh fruits and vegetables did not increase caloric intake, protein intake, or patient-reported quality of life compared to a strict neutropenic diet. Both diets resulted in suboptimal nutrition, eliminating the presumed key benefits of a less restrictive approach.
Previous neutropenic diet studies were flawed by using fever as an endpoint. Since only about 25% of fevers represent a true, documented infection, this trial's use of a robust "major infection" endpoint provided a much clearer and more accurate signal of dietary risk, revealing differences other studies missed.