Abstract: Objective To investigate the effect of programmed death receptor-1(PD-1)/programmed death receptor-ligand-1(PD-L1) inhibitor combined with chemotherapy on gastrointestinal function and inflammatory markers in peripheral blood of patients with advanced gastric cancer (AGC). Methods The clinical data of 128 AGC patients treated in our hospital from February 2022 to August 2023 were retrospectively analyzed, and they were divided into control group (64 cases received conventional chemotherapy) and study group (64 cases received PD-1/PD-L1 inhibitor treatment+conventional chemotherapy) according to different treatment schemes. The short-term curative effect, gastrointestinal function level and inflammatory markers in peripheral blood before and after three cycles of treatment were recorded between the two groups, and the adverse reactions of the two groups were counted. Results The objective response rate (ORR) and disease control rate (DCR) in the study group were higher than those in the control group(P<0.05). After three cycles of treatment, the levels of vasoactive intestinal peptide (VIP) and somatostatin (SS) decreased in both groups, while the levels of gastrin (GAS), motilin (MTL), and cholecystokinin (CCK) increased compared with those before treatment. The VIP and SS levels in the study group were lower than those in the control group, while the GAS, MTL, and CCK levels were higher (P<0.05). After three cycles of treatment, the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) decreased, and the lymphocyte-to-monocyte ratio (LMR) level increased in both groups compared with those before treatment. The NLR and PLR levels in the study group were lower than those in the control group, while the LMR level was higher (P<0.05). There was no statistically significant difference in the incidence of adverse reactions between the study group and the control group (P>0.05). Conclusion PD-1/PD-L1 inhibitors combined with chemotherapy for AGC can improve short-term efficacy, enhance gastrointestinal function, reduce NLR and PLR levels in peripheral blood, increase LMR levels in peripheral blood, and do not increase adverse reactions. The combination therapy is relatively safe.