Synbiotic Diet Prevents Escherichia coli Lipopolysaccharide-Induced Gut Dysbiosis and Intestinal Disruption After Weaning in Piglets

Post-weaning piglets are vulnerable to intestinal barrier disruption and microbiota imbalance, which can be exacerbated by bacterial endotoxin; this study assessed whether a synbiotic diet based on grape seed and camelina meals plus Lactobacillus probiotics can attenuate an <i>Escherichia coli</i> lipopolysaccharide (LPS) challenge. Twenty weaned piglets were randomized (n = 5/group) to control, LPS, synbiotic (SYN), or SYN+LPS diets for 21 days. The control diet consisted of a complete standard corn-soybean-based feed. The SYN diet contained a basal diet with 5% prebiotic mix (grape seed meal-camelina meal) and 0.1% probiotic mix including <i>Lactobacillus acidophilus</i>, <i>Lactobacillus paracasei</i>, and <i>Lactobacillus rhamnosus</i>; on day 21, the LPS and SYN+LPS animals received an LPS challenge and were sampled 3 h later. The expression of colonic genes coding for proteins like tight junctions, mucus/epithelial function, Toll-like receptors and signaling molecules involved in innate response was quantified by quantitative PCR arrays, and the microbiota composition was profiled by 16S rRNA sequencing. The LPS challenge reduced the expression of barrier- and mucus-associated genes and increased that of Toll-like receptors and signaling pathway markers, accompanied by microbial shifts, with reduced beneficial taxa and increased <i>Megasphaera elsdenii</i>. The synbiotic diet counteracted these transcriptional and microbial changes. Overall, the synbiotic supported epithelial integrity and moderated innate immune activation during acute endotoxin stress after weaning.