Manipulation of fecal pH by dietary means

Epidemiological and animal studies suggest that colonic fermentation and fecal pH may be risk factors for colorectal cancer. To modify these factors, we sought to develop a simple instrument for use in intervention studies. Three 14-day studies with 32, 40, and 30 healthy volunteers maintained on their regular diet were carried out to evaluate the effect of various food supplements on fecal pH. The interventions tested included supplementary lactulose, Metamucil, oat bran, wheat bran, or no supplement. The results showed that it is possible to provide a simple intervention to reduce fecal pH by 0.4 unit with oat bran administered at 75-100 g/day over a 14-day period, using a wheat combination, equivalent in macronutrients and fiber, as a control.