The intratumoral microbiota is a key modulator of the tumor immune microenvironment. This study aims to clinically validate a novel, AI-driven digital pathology biomarker-the Microbial-Sensory Coupling (MSC) index-which measures the spatial proximity between the intratumoral bacterium Campylobacter gracilis(C. gracilis) and host Trace Amine-Associated Receptor 1 (TAAR1)+ tumor cells. The study will evaluate whether the MSC index, measured in pre-treatment tumor biopsy tissues, can accurately predict clinical responsiveness and survival outcomes in ESCC patients undergoing anti-PD-1-based immunotherapy.