Bran as a dietary factor effect: Gastrointestinal tract function

The overall objective of this project was to investigate the effects of different milling methods and particle sizes of corn brans on human gastrointestinal tract function. The purpose of Study I was to determine the effect of different milling procedures and grind particle sizes of dietary corn bran on fecal output and the rate of passage of digested through the gastrointestinal tract in the human. The study consisted of a 5-day pre-period and two sections of 28 days each. Each of those two sections was composed of an introductory 7-day period and three periods of 7 days each. Five kinds of bread were fed. These included the following: (1) bread with no bran supplement; (2) bread with wet-milled, fine-ground corn bran; (3) bread with wet-milled, coarse-ground corn bran; (4) bread with dry-milled, fine-ground corn bran; and (5) bread with dry-milled, coarse-ground corn bran. Results indicated that fecal transit times were shorter, fecal wet weights were greater, and fecal percent moisture was greater, for subjects when fed the wet milled rather than the dry milled brans. Electron microscopy indicated that sharper margins of dry milled brans might cause intestinal mucosa wall damage. In Study II comparative effects of feeding the same corn brans on histological changes of gastrointestinal tract of 60 weanling mice were measured. Electron microscopy examination of intestinal walls indicated that wet milled and coarse ground brans produced less intestinal mucosa damage than did dry milled or fine ground brans. Weight gains of mice reflected these differences. Study III was a survey study which was designed to investigate the changes in dietary fiber intake of new immigrants to the United States of America from Asia. Results indicated that younger immigrants have made significantly greater changes in their food intake patterns than have older immigrants both in terms of selecting new foods and in times of reducing intakes of traditional foods. However, all changes which were made in diets did not necessarily result in lowered fiber intake. However, over-all dietary fiber intakes of subjects were significantly lowered following immigration to the United States