Mutagenicity of different fractions of extracts of human feces.

An extraction-fractionation scheme for the isolation of non-volatile fecal mutagens is described. Extraction of feces was with acetone, and a 2-step fractionation scheme employing silica gel SepPak cartridges and normal-phase high-pressure liquid chromatography was used. Assay of mutagens was with the standard plate mutagenicity assay with Salmonella typhimurium tester strains TA98 and TA100, with and without the Aroclor induced S9 microsomal activation system. Single feces samples from 24 donors from a wide socioeconomic spectrum were tested. It was found that most fecal mutagenicity extracted by aqueous acetone could be attributed to a lipid soluble mutagen active on both TA98 and TA100 that has been previously reported.