BALB/c mice were administered with quercetin or its derivatives (quercetin-3-glucoside, quercetin-4'-glucoside and rutin, 5 or 50 mg/kg BW) for 2 weeks. The mucosa of the small intestine were recovered and subjected to a microarray analysis using Affymetrix Mouse Genome 430 2.0 Array. A cluster analysis shows that only the "low dose group" had a significantly different gene expression profile from the negative control group.