Effect of Zearalenone on Microbial Spatial Differences in the Chyme and Intestinal Mucosa of Piglets

Zearalenone (ZEN) is a widely distributed estrogenic mycotoxin that compromises intestinal health in pigs, but its spatial difference ZEN and niche-specific regulatory effects on the intestinal microbiota remain largely unelucidated. In this study, 12 healthy three-way crossbred weaned piglets (Duroc × Landrace × Yorkshire) were randomly divided into two treatments. The control group (CON) was fed with the basal diet, and the treatment group (ZEN) was supplemented with 1.5 mg ZEA/kg of the basal diet for 28 days. Chyme and mucosal microorganisms in the duodenum, jejunum, ileum, colon and cecum were profiled by using 16S rDNA sequencing. The results indicated that ZEN significantly reduced the α-diversity of ileal chyme, while the abnormal increase in α-diversity of ileal and cecal mucosa represented a pathological signature of intestinal mucosal barrier damage induced by ZEN, which was detrimental to intestinal health. β-Diversity analysis revealed ZEN altered the microbial community composition of the cecal chyme. LEfSe analysis revealed gut segment-specific and niche-specific biomarker taxa among the groups, and functional prediction further indicated that ZEN exposure significantly perturbed key metabolic pathways: it downregulated nicotinate and nicotinamide metabolism as well as the citrate cycle in ileal chyme and upregulated the pentose and glucuronate interconversions pathway in cecal chyme. Collectively, this study demonstrated the effects of ZEN on the intestinal microbiota across spatial difference and ecological niches in weaned piglets, providing a basis for elucidating the microecological mechanisms underlying ZEN-induced intestinal injury in pigs.