In this prospective observational study, our objective was to investigate the serum levels of PM20D1 in GC patients following early EN and its potential correlations with lipid metabolism (including total cholesterol [TC], triglycerides [TG], high-density lipoprotein cholesterol [HDLC], and low-density lipoprotein cholesterol [LDLC]), nutritional markers (albumin [ALB] and prealbumin [PA]), and inflammatory factors (including IL-6, IL-1β, and C-reactive protein [CRP]). This evidence concerns the gene IL1B and gastric cancer.