This study aims to examine the effect of synbiotic nutmeg flesh extract and L. plantarum on intestinal morphology, stress indicators and bacterial populations in broiler chickens reared at high densities. Broiler chickens (body weight 142 ± 4,71 g) were randomly divided into five treatments, and each treatment was repeated five times, namely, T0 (negative control with a normal density of 10 birds/m2), T1 (positive control with a high density of 18 birds/m2), T2, T3, and T4 with a high density of 18 birds/m2. The synbiotic nutmeg flesh extract and L. plantarum were added to the feed from the eighth day at 0.5, 1.0, and 1.5 ml/kg for T2, T3, and T4, respectively. The results of the study showed that administering synbiotic nutmeg flesh extract and L. plantarum to broiler chickens reared at high density significantly (p<0.05) increased growth performance and villous length in the duodenum, jejunum, and ileum. In addition, this synbiotic also lowers the pH in the ileum and cecum, increases lactic acid bacteria and reduces coliform bacteria in the ileum and cecum, reduces the H/L and malondialdehyde (MDA) ratio and increases superoxide dismutase (SOD). Providing synbiotic nutmeg flesh extract and L. plantarum is also able to improve the performance and stress of broiler chickens raised at high densities.