Dietary psyllium fiber and fat: Impact on serum lipid concentrations, fecal bulking characteristics in humans, and bread production

A 56-day study was conducted to investigate the comparative interactions of feeding psyllium husk fiber with beef tallow or with safflower oil on serum lipid levels and fecal fat losses. Healthy adult humans (13) were fed safflower oil, safflower oil plus fiber, beef tallow, and beef tallow plus fiber diets. Safflower oil feeding, in general, produced lower blood serum lipid levels than did beef tallow. Addition of psyllium fiber resulted in an overall reduction in serum LDL/HDL cholesterol ratio. Dietary psyllium fiber consumption led to a 41.27% increase of fecal fat excretion. However, fecal fat losses were increased by psyllium fiber to a greater extent when beef tallow was fed (+59.5%) than when safflower oil was fed (+24.2%). Beef tallow diets led to a significantly higher percentage of palmitic acid excretion, while safflower oil diets led to significantly higher percentages of oleic and linoleic acid excretions.;In a second project, effects of psyllium fiber particle size on fecal bulking characteristics were investigated in healthy humans. Psyllium fiber consumption, especially if finely ground, significantly increased stool weight and decreased fecal transit time. Finely ground psyllium has a higher water holding capacity than does coarsely ground psyllium, which may explain this effect.;The purposes of the third study were to formulate acceptable whole wheat breads containing high levels of psyllium fiber and to examine the effect of particle size of psyllium fiber on the properties of baked products. Objective test results indicated that psyllium fiber, when added to whole wheat bread, did not change the volume and firmness properties, but increased the weight of the baked products. Sensory test results found that high fiber breads had above average acceptability, although coarse psyllium fiber tended to lower the ratings of flavor, texture, and overall acceptability of the bread. Bread with fine ground psyllium fiber had sensory ratings which were not significantly lower than those of the control bread.