Long-term effect of wholemeal bread on stool weight, transit time, fecal bile acids, fats, and neutral sterols

Abstract

Stool weight, fecal constituents, bile acids, fat, neutral sterols, and intestinal transit time were recorded in 28 subjects over 18 mo. During the first 12 mo the subjects ate white bread. They were studied for an initial period of 7 days, and after 6 mo (study period 1). For the first 6 mo they ate their usual intake of bread, they then increased their white bread intake by 62 g/day for 6 mo (study period 2). The subjects ate a self-selected diet throughout the 18 mo study. During the last 6 mo (study period 3) the subjects replaced white bread by the same amount of wholemeal bread as in study period 2. No increase in stool weight occurred until study period 3 when there was an increase of 20%. There developed a linear relationship between stool weight and intestinal transit time which was not found during the initial first and second study periods. A seasonal influence on serum cholesterol was not observed during the wholemeal bread period. Fecal bile acid excretion was unchanged throughout the experiment.