Effects of Nutritional Intervention on Clinical Recovery and Nutritional-Immunological Status (Evaluated by GLIM, CONUT, and PNI Criteria) in Gastric Cancer Patients After Total Gastrectomy

Background: Total gastrectomy (TG) for gastric cancer induces severe metabolic stress, altered gastrointestinal function, and rapid post-surgical immunonutritional decline. This study evaluated the clinical efficacy of a structured perioperative nutritional intervention on clinical recovery, overall malnutrition (GLIM criteria), and immunonutritional reserves (PNI and CONUT scores) in post-TG patients. Methods: A controlled, non-randomized interventional study was conducted on 76 gastric cancer patients undergoing TG at Vietnam National Cancer Hospital (2023–2024), divided equally into an intervention group (n = 38) and a matched control group (n = 38). The intervention arm received 1 month of individualized nutritional counseling, a disease-specific diet, and an immunonutrient-enriched hydrolyzed peptide supplement (arginine, glutamine, nucleic acids, omega-3 fatty acids). Clinical recovery metrics (time to first flatus, oral feeding initiation, length of stay), GLIM-defined malnutrition, and immunonutritional indicators (PNI and CONUT scores) were evaluated. Results: Baseline demographic and clinical characteristics were homogeneous between groups. The structured intervention significantly accelerated functional gastrointestinal recovery: time to first flatus (56.4 ± 12.1 vs. 128.1 ± 80.6 hours, p < 0.001) and time to initiate oral feeding (48.2 ± 8.4 vs. 141.0 ± 76.7 hours, p < 0.001) were markedly reduced. Consequently, length of hospital stay was shortened by nearly four days (8.4 ± 1.8 vs. 12.2 ± 3.9 days, p < 0.001). Postoperative malnutrition progression at follow-up was significantly attenuated in the intervention group (86.8% vs. 100%, p = 0.0135). Furthermore, in elderly patients (≥60 years), the intervention preserved immunonutritional status, resulting in significantly lower rates of abnormal PNI (33.3% vs. 81.0%, p = 0.0043) and high-risk CONUT scores (47.6% vs. 90.5%, p = 0.0063). Conclusions: Early structured perioperative nutritional intervention accelerates gastrointestinal recovery, shortens hospital stay, mitigates post-gastrectomy catabolic malnutrition, and preserves visceral protein and immunological reserves in elderly patients following total gastrectomy.