RESUMEN
The objective of the current study was to investigate the effects of isomalto-oligosaccharide (IMO), Chinese herbal medicine extract (CHE) or their combination on the growth performance, diarrhoea incidence, serum biochemical profiles, inflammatory cytokine expression, intestinal morphology and microflora of weaned piglets. Thirty-two ([Landrace × Yorkshire] × Duroc) piglets, weaned at 25 days of age, were randomly assigned into four groups. Group I was fed the basal diet. Group II were fed a basal diet supplemented with 2 g/kg IMO for 14 consecutive days and then 4 g/kg IMO for another 14 days. Group III were fed diet with 0.5 g/kg CHE for 14 days and 1 g/kg CHE for another 14 days. Group IV were fed diet with (2 g/kg IMO + 0.5 g/kg CHE) for 14 days and (4 g/kg IMO +1 g/kg CHE) for another 14 days. Results showed that diets supplemented with IMO, CHE or their combination did not influence the diarrhoea rate and intestinal morphology, while co-administration of IMO with CHE tended to have higher average daily gain. Serum biochemical analysis showed that dietary CHE decreased aspartate aminotransferase levels, while inclusion of IMO led to a decrease in high-density lipoprotein. Moreover, co-administration of IMO with CHE significantly upregulated the expression of TGF-ß, a potent anti-inflammatory cytokine, in jejunal mucosa of piglets. Further, CHE significantly increased the abundance of Bifidobacterium in ileal digesta. Meanwhile, the combination of IMO and CHE significantly increased Bifidobacterium in the caecum of piglets. Additionally, dietary IMO, CHE or their combination significantly reduced the number of potential entero-pathogen Escherichia coli in ileal contents and Clostridium species in caecal digesta. These results indicated that application of IMO or CHE could favourably modulate the intestinal microbial composition of piglets, while their beneficial impact and molecular mechanism on intestinal health warrants further investigation.