Multi-omics profiling reveals that glycerol monooleate inhibits PEDV replication and attenuates intestinal injury of piglets by enhancing antioxidant capacity, modulating the TNF signaling pathway, and reshaping the intestinal microbiota

Abstract This study investigated the protective effects of glycerol monooleate (GMO) against porcine epidemic diarrhea virus (PEDV)-induced intestinal injury in neonatal piglets. Twenty-four 7-day-old piglets were divided into four groups: CTRL, GMO, PEDV, and PEDV + GMO. From D 4–10, piglets in GMO groups received 100 mg/kg GMO supplementation. Piglets in PEDV–infected groups were challenged with 10⁶ TCID₅₀ PEDV per piglet on D 8. Blood and intestinal samples were collected from all piglets after euthanasia on D 11 to assess intestinal morphology, oxidative stress status, inflammatory response, and intestinal microbiota. PEDV infection significantly reduced average daily gain (ADG) during D 9–11 (P < 0.05), impaired intestinal barrier function indicated by lower plasma D-xylose, increased duodenal crypt depth (CD) and decreased villus height (VH) and VH/CD ratios in duodenum, jejunum, and ileum. PEDV caused oxidative stress, elevating plasma and duodenum malondialdehyde (MDA) content, plasma hydrogen peroxide (H₂O₂) content, and myeloperoxidase (MPO) activity, while duodenum catalase (CAT) activity declined (P < 0.05). PEDV activated systemic inflammation through TNF-α signaling pathway, indicated by upregulating IRF7, MX1, IFN-β, OASL, ISG15, TNF-α, and CXCL2 mRNA, and elevating plasma IL-1β and TNF-α contents (P < 0.05). Gut microbiota analysis revealed PEDV increased abundance of Fusobacterium, Collinsella, and Campylobacterota while reducing Bacteroidetes and Alloprevotella (P < 0.05). GMO supplementation attenuated PEDV-induced intestinal injury, indicated by increasing ileal VH, reducing duodenum and ileum CD, and therefore improving ADG (P < 0.05). GMO enhanced antioxidant capacity via increasing CAT in plasma and total superoxide dismutase (T-SOD) activities in duodenum and suppressing MDA in ileum and H₂O₂ levels in plasma and jejunum (P < 0.05). GMO inhibited viral replication and modulated TNF-α signaling pathway, downregulating IRF7, MX1, ISG15, OASL, TNF-α, and CXCL2 expression, reducing plasma IL-1β and TNF-α concentrations (P < 0.05). In addition, GMO suppressed abundance of pathogenic bacteria such as Escherichia coli and Shigella spp (P < 0.05). These findings demonstrate that GMO inhibits PEDV replication and alleviates PEDV-induced intestinal damage through multifaceted mechanisms: enhancing antioxidant capacity, mitigating inflammatory responses via TNF pathway regulation, and balancing gut microbiota.