Influence of dietary fiber on insulin receptors in rat intestinal mucosa.

This study was designed to determine the effect of dietary carbohydrate and fiber on mucosal insulin receptors, in order to correlate changes in cellular proliferation with hormonal responsiveness. In two protocols insulin binding was significantly affected by the consumption of dietary fiber. Compared to fiber-free, feeding corn bran increased binding in the duodenum 30% and ileum 50% but decreased binding in the jejunum 44%, and feeding guar gum increased binding in the colon 73% but decreased binding in the jejunum 40%. Feeding wheat bran or oat bran increased binding 50% in the small intestine compared to cellulose or fiber-free. Receptor autophosphorylation was 30% higher with fiber-free or wheat bran feeding than cellulose or oat bran. These changes in receptor binding and activity may correlate with altered rates of cell proliferation induced by dietary fiber.