NCBI ROFL: Pilot study of the effect of diet on the mutagenicity of human faeces.

"A healthy non-smoking man, consuming a normal 'western' diet (meat, vegetables, bread and alcohol) collected five consecutive complete bowel movements. He then added an extra 150 g of fat (from butter, cheese, milk, chocolate, peanuts, bacon and eggs) to his daily diet for 2 weeks, and collected four further consecutive bowel movements in the second week. After 6 months on his normal diet, he added 30 g of wheat bran to his daily diet for 3 weeks, and collected four complete stool samples in the third week. Aqueous faecal extracts were prepared and assayed for auxotrophic growth-enhancement and bacterial mutagenicity (using fluctuation tests with Salmonella typhimurium TA100 and Escherichia coli WP2uvrApKM101). There was no significant difference in faecal wet weight between 'normal' and 'high-fat' collections, but addition of 30 g bran was associated with a 1.8-fold increase in stool weight, in good agreement with published data. Fluctuation tests showed that ...