Long-term durability of infliximab maintenance therapy incorporating plant-based diet in inflammatory bowel disease.

Background: The new therapeutic modality incorporating a countermeasure against a westernized diet, i.e., a plant-based diet, showed far better outcomes than current standards in inflammatory bowel disease (IBD). Infliximab is widely used for induction and subsequent scheduled maintenance therapy in patients with IBD. However, the efficacy of infliximab diminishes over time. In the present study, we investigated the durability of scheduled infliximab maintenance therapy incorporating plant-based diet in IBD. Methods: This was a prospective single-group trial at tertiary hospitals. Infliximab maintenance therapy was indicated in patients with severe disease or those who were unresponsive to conventional therapy. Infliximab (5 mg/kg body weight) was infused every 8 weeks on an inpatient basis, and plant-based diet, a lacto-ovo-vegetarian diet, was served three- or four-times during hospitalization. Patients were instructed to continue the diet after discharge. Durability was assessed using the Kaplan-Meier method. Results: Twenty-four patients [16 with Crohn's disease (CD), eight with ulcerative colitis (UC)] were included: median age 27.5 years old, disease duration 53.5 months, and concomitant use of immunosuppressant 21%. Intensification of infliximab was employed in 46% of patients. There was no significant difference in durability rates between CD and UC. Durability rates were 87% at both 5 and 10 years. Plant-based diet score in the median follow-up period of 9.3 years, which indicates adherence to the plant-based diet, was significantly higher than the baseline score. Conclusions: Infliximab maintenance therapy incorporating plant-based diet yielded a high durability rate of 87% at 5 years in patients with IBD.