This study was conducted to investigate the effects of supplementing fermented mulberry leaves (FML) on intestinal morphology, antioxidant capacity, and immune function in the gut of finishing pigs. Eighteen 132-day-old healthy crossbred (Duroc × Landrace × Yorkshire) male castrated pigs were randomly divided into two treatment groups with nine replicates per group. The control (CON) group was fed the basal diet, and the FML group was fed the basal diet supplemented with 10% FML. The experiment lasted 69 days. The results showed that 10% FML improved gut health. The apparent total tract digestibility in dry matter, crude protein, crude fiber, neutral detergent fiber, acidic detergent fiber, ether extract, and crude ash increased in the 10% FML group of finishing pigs compared to the CON group (p < 0.05). Duodenal, jejunal, and ileal intestinal morphology, such as villus height and villus-height-to-crypt-depth ratio, increased in the 10% FML group compared to the CON group, whereas crypt depth decreased in the duodenum, jejunum, and ileum (p < 0.05). Total antioxidant capacity increased in the ileum of the 10% FML group compared with the CON group (p < 0.05). The FML supplementation improved the contents of duodenal immunoglobulin A, jejunal interleukin-1β, interleukin-8, ileal interleukin-1β, interleukin-6, interferon-γ, and immunoglobulins A and M compared to the control group (p < 0.05). Moreover, FML downregulated the mRNA expression levels of tumor necrosis factor-α in the duodenum, Toll-like receptor 4, nuclear factor-κ B-P65, and myeloid differentiation factor 88 in the jejunum, and Toll-like receptor 4 and nuclear factor-κ B-P65 in the ileum (p < 0.05). The FML also upregulated Montrose uniting church 1 in the duodenum and claudin 2 in the ileum (p < 0.05). In conclusion, dietary supplementation with 10% FML improved the gut health of finishing pigs and FML is a potential feed ingredient for pig breeding.

Echinacea polysaccharide (EPP) is one of the main active ingredients of Echinacea purpurea and has been shown to possess antioxidant, anti-inflammatory, and immune-enhancing activities. The study investigated the effects of supplementing the diet with different doses of EPP on immunosuppressed broilers. A total of 180 one-day-old healthy broilers were randomly assigned to six groups, each with six replicates of five birds. C (control) and CTX (cyclophosphamide) groups received basal diet, while LLEP, LEP, MEP, and HEP groups were supplemented with 100, 200, 400, and 800 mg/kg EPP. On day 7, group C was injected with saline for three consecutive days, whereas the remaining groups received cyclophosphamide (CTX, 80 mg/kg) to induce immunosuppression. Intestine, liver, and serum samples were collected on days 14 and 28 for analysis. The results showed that all EPP-supplemented groups exhibited improved growth performance compared to the CTX group, and the immune organ index increased. Specifically, the MEP group showed an improvement in jejunal morphology, and the LLEP and LEP groups improved ileal morphology. The EPP-added groups had improved ileal morphology The EPP-added group exhibited improved jejunal and ileal intestinal barriers, i.e., Occludin, Claudin1, Claudin2 and MUC2 at different time periods, as well as immune-related markers, at different time points. Furthermore, the MEP and HEP groups showed upregulated Nrf2 gene expressions in the jejunum and ileaum. EPP supplementation reduced MDA contents in serum, liver, and small intestine. The LLEP group effectively increased GSH-Px in serum and liver, while the MEP group effectively increased T-AOC in serum, liver, and small intestine. Meanwhile, compared to the CTX group, the MEP group showed increased ALB levels and all groups supplemented with EPP showed elevated TP levels. In conclusion, EPP ameliorated cyclophosphamide-induced immunosuppression in broilers, with the optimal effect observed at a supplementation level of 400 mg/kg (MEP group).