Breath hydrogen and methane responses of men and women to breads made withwhite flour or whole wheat flours of different particle sizes

Objective: While it is well known that consumption of whole grain foods res ults in beneficial health effects, the great majority of Americans prefer b read made with white flour. Consumption of whole grain foods in high fiber menus may cause undesirable intestinal responses. The purpose of this study was to determine whether consumption of bread made with ultra fine ground whole wheat flour retained beneficial effects while reducing undesirable ef fects. Methods: Twenty-six men and women (31 to 55 years of age) consumed glucose solutions or bread made with white, whole wheat or fine ground whole wheat flour (1 g carbohydrate/kg body weight) in a Latin square design after two days of controlled diet. Breath methane and hydrogen were determined over t he 24 hours after consumption of test foods. Results: Hydrogen and methane responses of men and women were similar. Ther e were no significant differences in methane responses to the different tre atments, but hydrogen response was increased by all breads (p<0.0001). Alth ough the overall mean response values were similar for all three breads, th e patterns of hydrogen response differed (treatment*time, p<0.003). Gastroi ntestinal symptoms were not associated with fiber content or particle size of bread; however, subjects reporting symptoms tended to have higher methan e responses (0.05<p<0.10). Conclusion: Neither fiber content of bread nor particle size of whole wheat flour substantially affected breath hydrogen or methane responses or gastr ointestinal symptoms. Fine ground whole wheat breads may provide a more acc eptable food choice than standard whole wheat bread without sacrificing the beneficial health effects of higher fiber.