Recent Perspectives on the Relations between Fecal Mutagenicity, Genotoxicity, and Diet

Abstract

DNA damage is an essential component of the genesis of colonic cancer. Gut microbial products and food components are thought to be principally responsible for the damage that initiates disease progression. Modified Ames tests and Comet assays have been developed for measuring mutagenicity and genotoxicity. Their relevance to oncogenesis remains to be confirmed, as does the relative importance of different mutagenic and genotoxic compounds present in fecal water and the bacteria involved in their metabolism. Dietary intervention studies provide clues to the likely risks of oncogenesis. High-protein diets lead to increases in N-nitroso compounds in fecal water and greater DNA damage as measured by the Comet assay, for example. Other dietary interventions, such as non-digestible carbohydrates and probiotics, may lead to lower fecal genotoxicity. In order to make recommendations to the general public, we must develop a better understanding of how genotoxic compounds are formed in the colon, how accurate the Ames and Comet assays are, and how diet affects genotoxicity.

Probiotic microorganisms detoxify ochratoxin A in both a chicken liver cell line and chickens

“…Secondary bile acids, branched chain fatty acids, saturated fats and toxins are associated with an increase in FW toxicity. Dietary interventions, such as prebiotics and probiotics, may lead to lower faecal genotoxicity …”

Mechanisms Linking Colorectal Cancer to the Consumption of (Processed) Red Meat: A Review

“…However, increased endogenous formation as the underlying cause for the association between red and processed red meat intake and CRC risk was also not supported by the observation that in the dietary intervention studies of Bingham's group Joosen et al, 2009;Joosen et al, 2010), no difference in fecal water genotoxicity in relation to meat intake was detected despite the increased fecal ATNC concentrations. Both masking of the genotoxic effect by genoprotective compounds present in the complex mixture of the fecal water and the inability of the used Comet assay in human-derived colonocyte cell lines to detect genotoxic chemicals in fecal water have been suggested in order to explain this unexpected result (Gratz et al, 2011). Furthermore, NOCs measured as ATNC may promote cancer through a non-genotoxic mode of action.…”

Comparison of in vivo and in vitro digestion on polyphenol composition in lingonberries: Potential impact on colonic health

“…ICR 191 (acridine mutagen) and fecal water challenge both induced frameshift mutations in HT29 (G17 neo) cells causing an increase in relative mutation frequency (RMF) of approximately 80% compared with the media-only control. Although ICR 191 is a classical frameshift mutagen, faecal water was used to induce mutagenicity given its biological relevance to the colonic environment [24,25].…”