Multi-omic (microbiome, metabolome, and immunome) study of peritumoral lymph nodes in gastric and colorectal cancer.

Interventions: Positive lymph nodes around gastric cancer:None;Negative lymph nodes around gastric cancer:None;Positive lymph nodes around colorectal cancer:None;Negative lymph nodes around colorectal cancer:None Primary outcome(s): Lymph nodes pathology diagnosis;Lymph nodes high-throughput sequencing;Metabonomics of lymph nodes;Immunomics of lymph nodes Study Design: Sequential