The Glutamate–Glutamine Axis in Pediatric Septic Shock: Immunometabolic Mechanisms, Biomarker Potential, and Clinical Implications

Pediatric septic shock remains a major cause of morbidity and mortality in critically ill children and is increasingly recognized as a syndrome of profound immunometabolic dysregulation. This narrative review synthesizes current clinical, translational, and mechanistic evidence on the glutamate–glutamine axis in pediatric septic shock. The review focuses on how glutamine and glutamate metabolism may interact with immune-cell function, mitochondrial substrate handling, redox defense, and intestinal barrier integrity, while distinguishing biological plausibility from validated clinical utility. Current evidence supports the glutamate–glutamine axis as a mechanistically relevant pathway and a source of candidate biomarkers, but pediatric-specific data remain limited and do not yet justify routine biomarker use or glutamine-based intervention in unselected children with septic shock. Future studies should use standardized sampling, reproducible analytical methods, pediatric validation cohorts, and phenotype-guided trial designs before this axis can be translated into clinical decision making.