Effects of dietary ergosterol supplementation on growth performance, antioxidant capacity, and intestinal health in weaned pigs

Ergosterol (ERG), a bioactive fungal sterol, possesses potent antioxidant and immunomodulatory properties, but its potential benefits on the intestinal health of weaned pigs remain largely unknown. To explore the effects of ERG on growth performance, antioxidant capacity, and intestinal health, 180 weaned pigs (21-d old, initial body weight 7.26 ± 0.26 kg) were randomly divided into 5 treatments with 6 replicate pens per treatment (6 pigs per pen) and fed with a basal diet (CON) or basal diet supplemented with 100, 200, 400, and 800 mg/kg ERG, respectively. The experiment lasted for six weeks. Results showed that, dietary ERG significantly decreased the diarrhea incidence ( P < 0.001), and the feed-to-gain ratio ( P = 0.038). Compared with the CON group, ERG supplementation at 200 and 400 mg/kg significantly decreased the serum concentration of urea ( P = 0.025) while dietary ERG quadratically decreased the concentration of malondialdehyde (MDA) ( P = 0.027). Dietary ERG supplementation linearly increased the serum concentration of IgG ( P = 0.044) and quadratically increased the serum level of immunoglobulin (Ig) M ( P = 0.007). In addition, compared with the CON group, ERG supplementation at 400 mg/kg significantly increased the serum concentration of glutathione peroxidase (GSH-Px) ( P = 0.025). Compared with the CON group, ERG supplementation at 200 mg/kg significantly increased the villus height, the abundance of ZO-1 protein, and the total antioxidative capacity (T-AOC) in the jejunal epithelium ( P < 0.05). ERG supplementation at 200 and 400 mg/kg increased the abundance of jejunal secretory immunoglobulin A (sIgA)-positive cells compared with that in the CON group ( P < 0.05). Moreover, ERG elevated the abundance of Lactobacillus and Bifidobacterium, and the concentrations of major short-chain fatty acids in the caecum ( P < 0.05). Importantly, ERG downregulated the expression level of IL-6 in the jejunum relative to the CON group ( P < 0.05). ERG supplementation at 200 mg/kg also decreased the expression levels of Caspase-9 and NF-κB in the duodenum and ileum, respectively ( P < 0.05). These results suggest a beneficial effect of ERG on the growth and intestinal health in weaned pigs, and such an effect may be closely associated with improved immunity, antioxidant capacity, and intestinal epithelial barrier function, as well as improved intestinal microbiota.