Shijie Li

Both carboxymethyl chitosan (CMCS) and Mn²⁺ can stimulate the cGAS-STING pathway to promote the production of immune factors such as type I interferons (I IFNs), thereby regulating the body’s immune response. In this study, a sustained-release Mn²⁺-loaded CMCS-Mn hydrogel was designed, and the synergistic effects of CMCS and Mn²⁺ on innate immunity, as well as factors influencing the immune response, were investigated. The optimal gel formulation was obtained with a CMCS concentration of 1 mg/mL and a MnCl₂ concentration of 0.02 mol/L, yielding a gel with a particle size of 472.16 nm, a polydispersity index of 0.35, a Mn²⁺ content of 1.488 mg/g, and a specific surface area of 4.74 m²/g. The hydrogel forms mainly via coordination interactions between Mn²⁺ and the amino and carboxyl groups on CMCS molecular chains and exhibits pH-dependent Mn²⁺ release behavior. Cellular assays demonstrated that the combination of 600 μg/mL CMCS-Mn²⁺ hydrogel and 5 μg/mL free Mn²⁺ produced the strongest IFN-β induction. The hydrogel exhibits synergistic immunomodulatory effects of both CMCS and Mn²⁺; while the amino groups are critical for the immunological activity of CMCS, Mn²⁺ plays a more prominent role. Partial substitution of Mn²⁺ by Ca²⁺ can loosen the cross-linked network and further modulate Mn²⁺ dissociation from the hydrogel.

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.

The impact of nutritional enrichment with bio-fermented distillers grain (FDG) on broiler growth, intestines, and cecal microbial community were evaluated. A total of 240 five-day-old male chicks were randomly and evenly distributed into three treatment groups (each with eight biological replicates of 10 chicks): 0% FDG (group A), 2.5% FDG (group B), and 5% FDG (group C). In this study, we observed that FDG caused no significant variations in the body weight and feed intake of broilers (p > 0.05). The FDG significantly enhanced villus height and the villus height/crypt depth ratio (VCR) of the small intestine compared with the control group (p < 0.05). Taxonomic composition of the gut microbiota revealed a higher relative abundance of Bacteroidetes in the cecal samples of broilers from groups B and C compared to the control group (p < 0.05). At the genus level, the relative abundances of Bacteroides and Phascolarctobacterium were increased with the addition of FDG to broiler diets, whereas the relative abundance of the Christensenellaceae_R-7_group was decreased. These results suggest that fermented feeds significantly influence the composition of cecal microbiome in broilers, potentially affecting growth performance, nutritional status, and intestinal health.