Effect of a Natural Inulin-Containing Product, “Kikuimo Extract” on Intestinal Microbes and Gene Expression in the Liver and Adipose Tissue of Menopausal Monkeys

Abstract

Inulin is a soluble and indigestible fiber derived from natural plants such as Jerusalem artichoke ( Helianthus tuberosus ), “Kikuimo”. In the current study, a nutrigenomics approach was utilized to evaluate the in vivo function of “Kikuimo Extract” (KE) in ovariectomized cynomolgus macaque, a post-menopausal non-human primate model. KE was administered orally before feeding, for 3 months for the following examinations: 1) the effect of KE on intestinal microbes was examined by quantitative analyses of the intestinal bacteria using real-time PCR with DNA extracted from monkey feces; 2) the effect of KE on gene expression was investigated by real-time RT-PCR using RNA extracted from both the liver and adipose tissue of the monkeys. KE administration modulated menopause-mediated altered microbes to increase Lactobacilli, Veillonella , and Bacteroides in all monkeys. KE administration regulated the altered expression of functional genes, SCAP, LDLR, and LXRA (lipid metabolism); GLUT -4 (glucose transport); CYP1A 1 and CYP1A 2 (drug metabolism); and CYP -17-2 and CYP -19-2 (E2 synthesis) in the menopausal monkeys. In menopausal monkeys, KE showed potent prebiotic effect on beneficial microflora and regulating effect on altered expression of functional genes associated with metabolism and E2 production. Thus, KE appears to be a practical functional food that alleviates the altered conditions of intestinal microbes and gene expression in the liver and adipose tissue in a menopausal state.