Beneficial effect of nisin supplementation at different dosages on the growth performance, diarrhea rate, immunity, and fecal microbial community of weaned piglets

Abstract BACKGROUND Nisin, an antimicrobial peptide produced by Lactococcus lactis ssp. lactis , is widely used as a natural preservative for many food products. However, its effects on the growth performance and intestinal health of weaned piglets are unknown. This study aimed to investigate the protective effect of nisin on the growth performance, immune functions, short‐chain fatty acids (SCFA) levels, and fecal microbiota of weaned piglets. RESULTS Our findings revealed that the N2 group (200 mg kg −1 nisin) showed increased average daily grain, and N1 (100 mg kg −1 nisin) and N2 groups showed reduced feed‐to‐weight ratio ( P < 0.05). There were linear and quadratic influences on diarrhea frequency and index as nisin level increased ( P < 0.05). Nisin supplementation increased the serum immunoglobulin (Ig)A, IgG and IgM at day 14 and day 28 ( P < 0.05), whereas it reduced the levels of interleukin (IL)‐1β, IL‐6, and tumor necrosis factor α ( P < 0.05). Besides, nisin supplementation markedly increased fecal acetic acid, propionic acid, and butyric acid ( P < 0.05), especially in the N2 group. More importantly, nisin supplementation markedly changed the microbial diversity and composition, as indicated by reduced abundance of Clostridium_sensu_stricto_1 ( P < 0.05) and increased abundance of Rikenellaceae_RC9_gut_group ( P < 0.05). Spearman correlation analysis demonstrated a close relationship between serum biomarkers and fecal microbiota ( P < 0.05). CONCLUSION Overall, dietary supplementation of nisin enhanced the growth performance and immune status of weaned piglets, which was linked with the change in microbiota and derived SCFAs. Supplementation with 200 mg kg −1 nisin showed the best effect on piglets. © 2025 Society of Chemical Industry.