Abstract 3732: Associations between gut microbiome changes and quality of life in colorectal cancer patients: a pre- and post-surgery comparison

Abstract With the increasing number of colorectal cancer (CRC) survivors, understanding how treatment impacts health-related quality of life (QoL) and microbiome composition is critical. This study investigated the relationship between QoL metrics and microbiome changes before and after surgery in CRC patients, utilizing the EORTC QLQ-C30 and QLQ-CR29 questionnaires alongside clinical metadata. Additionally, the study explored how persistent symptoms, weight changes, and physical activity levels post-surgery influence QoL and microbiome diversity. Survey data were collected from 38 patients who completed pre- and post-surgery QoL assessments and provided matched fecal samples. Part I of the survey assessed health and lifestyle habits, including exercise levels quantified by MET-minutes, while Part II evaluated QoL using functional and symptom scales. Patients were classified as high-risk based on functional (≤33.32) or symptom scale scores (>66.66). Matched fecal samples were analyzed by sequencing the V3-V4 regions of the 16S rRNA gene, with taxonomy assigned using a besttax approach and processed via the QIIME pipeline. Microbiome analyses included differential abundance testing (using ALDEx2 and DESeq2) and diversity metrics (alpha and beta diversity). Significant changes were reported in functional scales, including body image and weight concern, and in symptom scales, such as blood and mucus in stool and stool frequency, between baseline and follow-up surveys. Microbiome analysis identified significant differences in taxa such as Peptostreptococcus, Parvimonas, and Prevotella pre- and post-surgery. While trends toward higher microbial diversity were observed in patients with increased physical activity or weight gain, these were not statistically significant. Symptom severity was associated with distinct microbial profiles: patients with frequent symptoms like blood and mucus in stool exhibited higher levels of Collinsella and Senegalimassilia, alongside lower abundances of beneficial genera like Ruminococcus and Dialister. By integrating QoL survey data with microbiome profiles, this study highlights the potential for personalized symptom management based on distinct microbial patterns linked to specific symptoms. Such insights enable tailored interventions to address both colorectal cancer-related symptoms and broader QoL concerns in survivors. A nuanced understanding of these relationships can guide targeted strategies to improve symptom control, enhance quality of life, and support comprehensive recovery through optimized microbial diversity. Citation Format: Hyeree Park, Donghyeok Seol, Ji Won Park, Min Jung Kim, Seung-Yong Jeong, Aesun Shin, Eun Sung Jung, Sunyoung Lee. Associations between gut microbiome changes and quality of life in colorectal cancer patients: a pre- and post-surgery comparison [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 3732.