Effects of Konjac Glucomannan on Putative Risk Factors for Colon Carcinogenesis in Rats Fed a High-Fat Diet

Abstract

The aim of this study was to determine effects of konjac glucomannan (KGM) in a high fat corn oil diet on risk factors of colon carcinogenesis, that is, fecal β-glucuronidase, mucinase, and bile acids, and on preventive factors, that is, fecal microflora and cecal short-chain fatty acids (SCFAs). Sprague-Dawley rats (n = 8 animals per group) were fed a normal-fat fiber-free (5% corn oil, w/w) or high-fat (25% corn oil, w/w) diet containing no fiber, KGM (5%, w/w), or inulin (5%, w/w, as a prebiotic control) for 4 weeks. Results indicated that the high-fat fiber-free diet significantly elevated the fecal β-glucuronidase and mucinase activities and total bile acid concentration and decreased cecal SCFA contents, as compared with its normal-fat counterpart. The incorporation of KGM, as well as inulin, into the high-fat fiber-free diet beneficially reduced the fecal β-glucuronidase and mucinase activities and lithocholic acid (secondary bile acid) concentration. Although KGM elevated the daily fecal total bile acid excretion, the change was due to the primary, instead of the secondary, bile acids. In addition, KGM beneficially promoted the daily fecal excretion of bifidobacteria and lactobacilli and cecal SCFA contents, as compared with the high-fat fiber-free diet. Therefore, the present study suggests that KGM potentially attenuated the high fat-induced risk in colon carcinogenesis.

Cloning and evaluation of reference genes for quantitative real-time PCR analysis inAmorphophallus

“…When used in food and ingested in the human digestive tract, KGM contributes to healthier digestion and the excretion of solid waste (Arvill & Bodin, 1995; Kaats, Bagchi & Preuss, 2015). Studies have also shown that KGM and some alkaloids in Amorphophallus have inhibitory effects on many diseases (Doi et al, 1979; Fan et al, 2008; Wu & Chen, 2011). Current transcriptome data for Amorphophallus have been deposited in the NCBI database, and these data accelerate the progress of studies on the important genes and in the molecular breeding of this species (Gille et al, 2011; Zheng et al, 2013).…”

Effect of dietary prebiotic supplementation on advanced glycation, insulin resistance and inflammatory biomarkers in adults with pre-diabetes: a study protocol for a double-blind placebo-controlled randomised crossover clinical trial

“…The SCFA butyrate, produced as a bacterial by-product of inulin fermentation, has been shown to increase colonic glutathione production [104]. Glutathione is an antioxidant co-factor required for glyoxalase I activity, an enzyme which degrades the AGE precursor methylglyoxyl.…”

Burdock Fermented byAspergillus awamoriElevates CecalBifidobacterium, and Reduces Fecal Deoxycholic Acid and Adipose Tissue Weight in Rats Fed a High-Fat Diet

“…14) These acids, which are highly cytotoxic intestinal microbial metabolites of primary bile acid, promote colon cancer development. 15,16) A high-fat (HF) diet increases fecal secondary bile acids and decreases cecal organic acid production, 17) and is believed to increase the risk of colon cancer and of ulcerative colitis. 18,19) Our recent studies provide evidence of the favorable effects of certain polyphenols, which reduce secondary bile acids such as lithocholic acid and deoxycholic acid.…”