Bacillus Subtilis‐Fermented Red Bean (Red Bean Natto) Reduces Hyperlipidemia Levels in Hamsters Fed an Atherogenic Diet

The purpose of this study was to investigate the effects of 50% red beans ethanol natto extracts fermented by Bacillus subtilis on hyperlipidemia in hamsters. Forty male hamsters were randomly assigned to normal control, high-fat control, and high-fat with RBNE (red beans natto extracts) (200 and 1000 mg/kg BW) groups. RBNE treatment for 8 weeks significantly decreased the body and visceral fat weight in hamsters. Compared to the high-fat diet group, the plasma total cholesterol (TC), total triacylglycerol (TAG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and oxidized LDL (oxLDL) concentrations as well as atherogenic index of plasma AIP [Log(TAG/HDL-C)] were significantly lower in the RBNE-fed group. The consumption of RBNE significantly reduced the liver contents of TC, esterified cholesterol (CE) and alanine aminotransferase (ALT), and increased a regulator of lipid metabolism: peroxisome proliferator-activated receptor alpha (PPAR-alpha). Furthermore, the circulating level of irisin was decreased. Practical Application The oral administration of Bacillus subtilis-fermented red bean natto extract (RBNE), a popular Asian dessert, effectively moderated the metabolism of lipids and positively affected the blood and liver profiles of hamsters fed with a high-cholesterol and high-fat diet. Importantly, RBNE significantly suppressed the increase in visceral fat mass. Additionally, RBNE appears to protect the liver and alleviate the magnitude of fatty liver development. RBNE also upregulated PPAR-alpha protein expression in the liver, suggesting that supplementation may improve lipid metabolism in part through the beta-oxidation of lipids and promotion of lipid secretion. Furthermore, RBNE may ameliorate hyperlipidemia involving irisin, a newly identified hormone, in hamsters fed a cholesterol- and lipid-enriched diet. In conclusion, RBNE with high hypocholesterolemic activities may be helpful for patients with atherosclerosis.