However, studies in early, antipsychotic free stages remain scarce and often neglect confounding factors such as smoking and metabolic syndrome.<h4>Methods</h4>We measured two complementary markers: lipopolysaccharide-binding protein (LBP), reflecting endotoxin exposure and systemic immune activation, and intestinal fatty acid-binding protein (I-FABP), indicating gut epithelial damage and permeability changes, in blood from 96 acutely ill, antipsychotic-free Sz patients (61 first-episode, 35 relapsed) and 96 matched controls. Here, LBP is linked to metabolic syndrome.