The Association Between Microplastics and Macrogenomics and Metabolomics in Gastric Cancer

This This study is planned to collect blood, cancer and paracancer tissues, and stool samples from 20 patients with gastric cancer, 2 gastric cancer tissues (at least 1cm\^3 each), 2 gastric paracancer tissues (at least 1cm\^3 each), 2 venous bloods (5ml each), and 1 stool (at least 10g each) from each patient. Samples will be collected from December 2024 through November 2025, with an expected total of 140 samples. Sample collection, transportation, and storage are described in IV.2. \& 3. Samples will be analyzed for the type, nature, and abundance of microplastics by Laser Direct Infrared Spectroscopy (LDIR), Scanning Electron Microscopy (SEM), and Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC/MS), which is expected to detect microplastics such as polyamides, polyethylene terephthalate (PET), and polyvinyl chloride (PVC). At the same time, blood and tissue samples will be metabolomically assayed using NNR-IVD technology and macro-genomic sequencing will be performed to explore potential associations between microplastics and microbiota and metabolic pathways in gastric cancer patients. By analyzing the distribution characteristics of microplastics in gastric cancer patients and their relationship with microbial communities and metabolic pathways, this study will reveal the impact of microplastics on the tumor microenvironment and further understand their role in gastric cancer development and progression.