High Fibre Dietary Intervention in patients with Melanoma receiving Immune Checkpoint Inhibitors (HiFi-Mel)

This study involves a 9 week dietician-led dietary counselling intervention to escalate daily fibre intake to >30g per day, concurrent with a neoadjuvant immune therapy regimen for melanoma planned for surgical resection (Stage III or IV). The dietician will be experienced in the management of oncology patients and have motivational interview training. This involves a telehealth or face-to-face dietician consult at baseline (60 minutes), with provision of written resources developed specifically for the study (tables with fibre estimates for foods and portions, recipes, suggested meal plan and information sheet on the gut microbiome and impact of diet) and suggestion of use of the Easy Diet App. Further dietary consultations at weeks 1, 2, 3, 5, 7 and 9 (approx 30 minutes) will be undertaken. Based on their initial food frequency survey results and baseline 3-day food record result, the dietician will explore ways in which patients can adapt their diet and individualise recommendations for how fibre can be escalated. The dietary intervention occurs concurrently with 3 cycles of pembrolizumab (a standard of care), over a 9 week period. Surgery to remove the melanoma will occur from week 10 to 12 (also a standard of care). 3-day food records will be collected at baseline and at the end of weeks 3, 6 and 9 from which fibre intake will be measured. Although self-reported by patients, these will be verified by the dietician to optimise accuracy.