The purpose of this study was to evaluate the effects of the combined intake of potato peptides and boiled kintoki beans on lipid metabolism and intestinal fermentation in rats. The concomitant intake of these two food ingredients resulted in reduced serum non-HDL cholesterol concentration, while HDL-cholesterol concentration remained at the same level
compared to the control groups. This may be due to the tendency of higher expression levels of CYP7A1 and SR-B1 mRNA observed in rats fed both potato peptides and kintoki beans. Gene expression associated with lipid metabolism may also play a key role in this effect, as LDL receptor mRNA expression was significantly increased in the experimental group compared
with the control groups. Furthermore, there were significant increases in the intestinal levels of acetic, propionic and lactic acid in the experimental group. The group fed kintoki beans alone as well as the group fed both potato peptides and kintoki beans had significant increases in Lactobaccillus and Anaerobes populations.

Key words: Potato peptide, Kintoki bean, Serum cholesterol, Intestinal fermentation, Rat