A Fermented Herbal Formulation Improves Intestinal Health and Growth Performance in Post-Weaning Piglets

Weaning impairs intestinal function and growth performance in piglets. This study evaluated a fermented herbal formulation (FHF) composed of five bioactive herbal ingredients-Radix isatidis, Folium isatidis, Radix scutellariae, Fructus forsythiae, and Radix glycyrrhizae-fermented with Enterococcus faecium and Saccharomyces cerevisiae and characterized by flavonoids, phenolic acids, and hydroxylated fatty acids, using the porcine intestinal epithelial cell line (IPEC-J2) and weaned piglets. In vitro, IPEC-J2 cells were pretreated with FHF extract (100-1000 μg/mL) for 3 h prior to lipopolysaccharide (LPS) challenge. In vivo, 72 piglets were weaned at 32 days of age and, after a 3-day post-weaning adaptation period, entered a 35-day feeding trial. The piglets were then randomly assigned to three treatment groups: control (basal diet), A1 (basal diet + 0.4% FHF), and A2 (basal diet + 0.6% FHF during days 1-18, followed by 0.3% FHF during days 19-35). FHF dose-dependently alleviated the LPS-induced decrease in cell viability and suppressed IL-6, IL-8, IL-1β, and TNF-α expression. In piglets, the A2 group showed higher final body weight, average daily gain (ADG), and average daily feed intake (ADFI), lower feed conversion ratio (FCR), and a lower diarrhea rate than the control group. FHF also improved intestinal morphology, reduced serum TNF-α and diamine oxidase (DAO) levels, increased jejunal tight junction protein expression, enriched Limosilactobacillus and Lactobacillus, and elevated acetic and butyric acids. FHF improved intestinal health and growth performance in weaned piglets, with the A2 group showing the best overall efficacy.