Dietary Wheat Bran Lowers Colonic pH in Rats

The effect of chronic dietary wheat bran supplementation on the pH of gastrointestinal contents was examined in thirty-one Sprague-Dawley rats. Ten control rats received a fiber-free diet while twenty-one rats were fed the same diet plus a 20% wheat bran supplement. The fiber-fed rats developed a greater acidity of intestinal contents: cecal pH was 6.30 ± 0.07 (SEM) as compared to 6.76 ± 0.06 in the control group (P < 0.001). The effect on pH of gastric contents was the opposite, 3.90 ± 0.15 in the fiber-fed rats compared to 2.74 ± 0.33 in the controls (P < 0.01). These changes in gastrointestinal pH may be of relevance to the nutrient modulation of gastric and colonic tumor development. Wheat bran dietary fiber colonic pH gastric pH colonic cancer