Effects Of Dietary Supplementation With Plant Extracts On Intestinal Barrier Function In Weaned Piglets

Antibiotics are commonly provided to weaned piglets;however,this practice has become controversial due to increased occurrences of microbial resistance,and alternatives are needed.The aim of the present study was to investigate the effects of dietary supplementation with plant extracts(PE)on intestinal barrier function in weaned piglets.A total of 240 weaned piglets(d 25 ± 3)from 16 pens(15 piglets/pen)were randomly allocated to either antibiotics group(25% Quinocetone at 200 mg/kg and 4% Enduracidin at 800 mg/kg of the basal diet),or PE group(1000 mg/kg of the basal diet).After two weeks of feeding,blood,intestinal tissue,and colonic digesta samples were collected from one piglet per pen in each group.The experimental results were listed as follows:(1)Compared with the antibiotics group,no significant differences were observed in growth performance or diarrhea index.(2)Compared with the antibiotics group,no significant differences were observed in serum concentrations of D-lactic acid or diamine oxidase(DAO).(3)Dietary supplementation with PE tended to increase villus width of duodenum(0.05<P<0.1),decreased villus height(VH)and villus height to crypt depth ratio(VH/CD)of jejunum(P<0.05),as well as increased VH/CD of ileum(P<0.05).(4)Dietary PE supplementation tended to upregulate the m-RNA expression of ZO-1 in the duodenal mucosa(0.05<P<0.1),upregulated the m-RNA expression of ZO-1 in the jejunal and ileal mucosa(P<0.05).(5)Piglets supplemented with PE upregulated the m-RNA expression of IL-1β and IL-17 in the duodenal mucosa(P<0.05),downregulated the m-RNA expression of IFN-γ in the jejunal mucosa(P<0.05),and upregulated the m-RNA expression of TLR-4 and NF-κb in the ileal mucosa(P<0.05).(6)Conversely,colonic microbiome results showed that PE supplementation increased Chao1,ACE,observed species(OS),and phylogenetic distance(PD)indexes in weaned piglets(P<0.05).Dietary PE supplementation increased the relative abundance of Actinobacteria,Cyanobacteria and Others(P<0.05),decreased the relative abundance of Saccharibacteria at the phylum level(P<0.05).Piglets fed the PE-supplemented diet increased the relative abundance of Bacillales and Coriobacteriales at the order level(P<0.05).PE supplementation increased the relative abundance of Eubacterium and Streptococcus(P<0.05),decreased the relative abundance of Subdoligranulum at the genus level(P<0.05).(7)Colonic metabolites results showed that PE supplementation decreased the content of butyrate and valerate(P<0.05).Taken together,it is speculated that PE would be a potent alternative to prophylactic antibiotics in improving the gut health in weaned piglets.