title: Fecal water as a non-invasive biomarker in nutritional intervention: comparison of preparation methods and refinement of different endpoints.
abstract: The assessment of cellular effects by the aqueous phase of human feces (fecal water, FW) is a useful biomarker approach to study cancer risks and protective activities of food. In order to refine and develop the biomarker, different protocols of preparing FW were compared. Fecal waters were prepared by 3 methods: (A) direct centrifugation; (B) extraction of feces in PBS before centrifugation; and (C) centrifugation of lyophilized and reconstituted feces. Genotoxicity was determined in colon cells using the Comet assay. Selected samples were investigated for additional parameters related to carcinogenesis. Two of 7 FWs obtained by methods A and B were similarly genotoxic. Method B, however, yielded higher volumes of FW, allowing sterile filtration for long-term culture experiments. Four of 7 samples were non-genotoxic when prepared according to all 3 methods. FW from lyophilized feces and from fresh samples were equally genotoxic. FWs modulated cytotoxicity, paracellular permeability, and invasion, independent of their genotoxicity. All 3 methods of FW preparation can be used to assess genotoxicity. The higher volumes of FW obtained by preparation method B greatly enhance the perspectives of measuring different types of biological parameters and using these to disclose activities related to cancer development.
authors.affiliation: Department of Nutritional Toxicology, Institute for Nutrition, Friedrich-Schiller-University, Jena, Germany.
authors.forename: Annett
authors.initials: A
authors.lastname: Klinder
authors.forename: Pernilla C
authors.initials: PC
authors.lastname: Karlsson
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Clune
authors.forename: Roisin
authors.initials: R
authors.lastname: Hughes
authors.forename: Michael
authors.initials: M
authors.lastname: Glei
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Rafter
authors.forename: Ian
authors.initials: I
authors.lastname: Rowland
authors.forename: John K
authors.initials: JK
authors.lastname: Collins
authors.forename: Beatrice L
authors.initials: BL
authors.lastname: Pool-Zobel
mesh_terms: D000818:Animals; D015415:Biomarkers; D019411:Clinical Laboratory Techniques / Q000592:standards*; D003110:Colonic Neoplasms / Q000453:epidemiology; D020552:Comet Assay; D004249:DNA Damage; D005243:Feces / Q000737:chemistry*; D019073:HT29 Cells; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology; D018570:Risk Assessment; D014867:Water
chemical_list: D015415:Biomarkers; D014867:Water