S3175 A Vegan and Allergy-Friendly Alternative for Gastric Emptying Scintigraphy: Validation in Healthy Participants

Introduction: Gastric emptying (GE) scintigraphy, the gold standard for evaluating gastroparesis, utilizes a Technetium-99m–labeled egg-based meal containing approximately 320 kcal and 30% fat, with a 4-hour imaging protocol developed and validated at Mayo Clinic with an intra-individual physiological variability (COVintra) for 2 replicate studies of 23.8%. However, its reliance on animal-derived ingredients presents a barrier for patients with egg allergies, lactose intolerance, and those adhering to vegan/plant-based, or other allergen-restricted diets. Our group recently validated a vegan and allergy-friendly alternative in vitro. This study aimed to evaluate a standardized, plant-based meal free from egg, dairy, gluten, and nuts, that is calorically and nutritionally comparable to the standard egg meal. Methods: Ten healthy adult volunteers participated in a randomized, crossover design. Each underwent GE scintigraphy with both the standard egg and vegan JUST Egg (primarily made of mung beans) meals, spaced 3-14 days apart. GE parameters, including gastric retention at 2 and 4 hours and gastric half emptying time (T1/2), were measured for the JUST Egg meal and benchmarked against the standard chicken egg meal. The primary outcomes of interest were GE T1/2 and the percentage emptied at 4 hours. Secondary outcomes included the percentage emptied at 2 hours, lag time (defined as the time for 10% of the meal to empty from the stomach), and COVintra between the 2 test meals. Statistical analysis included Mann-Whitney rank sum testing and Blant-Altman analysis. Results: Gastric retention at 2 and 4 hours, as well as GE T1/2 demonstrated consistent agreement between the two meals. Observed differences were not statistically significant and remained consistently low across the different parameters: the mean difference in GE T1/2 was under 10 minutes, in GE at 4 hours was <2%, and in GE at 2 hours was <10%. The COVintra for GE T1/2 between egg and vegan meals was 18.8%. Conclusion: The vegan JUST Egg meal demonstrated in vivo GE performance comparable to the conventional chicken egg meal. The observed GE T1/2 COVintra was below the previously established 23.8% for the standard egg meal. Therefore, this vegan, allergy-friendly meal offers a valid and inclusive alternative for GE scintigraphy, supporting broader clinical implementation.