Effects of capsicum oleoresin, garlic botanical, and turmeric oleoresin on gene expression profile of ileal mucosa in weaned pigs.

This study was conducted to characterize the effects of feeding 3 plant extracts on gene expression in ileal mucosa of weaned pigs. Weaned pigs (n = 32, 6.3 ± 0.2 kg BW, and 21 d old) were housed in individual pens for 9 d and fed 4 different diets: a nursery basal diet as control diet, basal diet supplemented with 10 mg/kg of capsicum oleoresin, garlic botanical, or turmeric oleoresin. Results reported elsewhere showed that the plant extracts reduced diarrhea and increased growth rate of weaning pigs. Total RNA (4 pigs/treatment) was extracted from ileal mucosa of pigs at d 9. Double-stranded cDNA was amplified, labeled, and further hybridized to the microarray. Microarray data were analyzed in R using packages from the Bioconductor project. Differential gene expression was tested by fitting a mixed linear model equivalent to ANOVA using the limma package. Bioinformatics analysis was conducted by DAVID Bioinformatics Resources. Three pairwise comparisons were used to compare each plant extract diet with the control diet. Quantitative real time PCR was applied to verify the mRNA expression detected by microarray. Compared with the control diet, feeding capsicum oleoresin altered (P < 0.05) the expression of 490 genes (280 up, 210 down), and feeding garlic botanical altered (P < 0.05) the expression of 64 genes (33 up, 31 down), while feeding turmeric oleoresin altered (P < 0.05) the expression of 327 genes (232 up, 95 down). Compared with the control diet, feeding capsicum oleoresin and turmeric oleoresin increased [Expression Analysis Systematic Explorer (EASE) < 0.05] the expression of genes related to integrity of membranes and tight junctions, indicating enhanced gut mucosa health, but decreased (EASE < 0.05) the cell cycle pathway. Feeding each of the 3 plant extracts enhanced (EASE < 0.05) the expression of genes associated with immune responses, indicating that feeding these plant extracts may stimulate the immune responses of pigs in the normal conditions. In conclusion, plant extracts regulated the expression of genes in ileal mucosa of pigs, perhaps providing benefits by enhancing the gut mucosa health and stimulating the immune system.