Randomized study to assess colonic microbiome changes in response to energy drink consumption (ROSANNA Trial).

TPS325 Background: Colorectal cancer (CRC), the second leading cause of cancer deaths in the US, is increasingly diagnosed in individuals under 50. This rise in early-onset CRC (eoCRC) led the U.S. Preventative Services Task Force to recommend a reduction in the age to begin colorectal cancer screening in average-risk persons, from 50 to 45. The etiology of eoCRC is multifaceted, with one postulated theory pointing to alterations in the young adult colonic microbiome. Hydrogen sulfide (H 2 S) producing bacteria, like Bilophila wadsworthia , Fusobacterium nucleatum and Atopobium parvulum , are typically minor gut microbiota components but are overrepresented in CRC cases, linked to inflammation, and may promote a pro-carcinogenic environment. These bacteria preferentially use taurine, an essential amino acid, as a primary energy source. Energy drinks represent one of the largest dietary sources (6-16x normal daily intake) of taurine in contemporary diets. Our hypothesis is that high taurine levels in energy drinks could exacerbate CRC risk by promoting preferential growth and metabolic activities of already present H 2 S-producing bacteria, contributing to the rise of eoCRC. Methods: This randomized open-label trial is actively enrolling up to 60 young adults (18-40 years) without personal or family history of CRC, other major GI disease/distress, and baseline infrequent energy drink consumption. Group 1 (Arm A; n=30), will consist of subjects consuming at least one of two protocol-specified energy drinks daily for 4 weeks. Group 2 (Arm B; n=30), will consist of usual dietary intake. Enrollments are randomized 1:1 and stratified, by gender, age (18-25 vs. 26-40), and baseline energy drink consumption (rare/none vs. 1-2 per week). Every subject will complete: 1) a daily dietary and fitness log, 2) a weekly wellness log, 3) collection of stool/saliva/skin/urine at 3 sequential time points (baseline, after 2 weeks, after 4 weeks), and 4) blood collection at the same time points. The primary endpoint is the change in H 2 S-metabolizing bacterial communities between baseline and 1 month of energy drink exposure within Arm A and also compared to those in Arm B using microbiome analysis (diversity, taxonomy, sulfur-enriched gene pathways). Several secondary and exploratory assessments include changes related to subject demographic and dietary differences, concordance of microbiome changes with dietary logs and in other biospecimens beyond stool, H 2 S-production measurements, and analyses of subject metabolic and immune function. Trial opened in February 2024 with active enrollment ongoing. Updated data on trial status and any amendment modifications will be presented at the meeting. Clinical trial information: NCT06137248 .