RESISTANT STARCH IN THE DIET INCREASES BREATH HYDROGEN AND SERUM ACETATE IN HUMAN-SUBJECTS

The colonic fermentation of two diets differing in amounts of resistan t starch (RS) was studied. High- and low-RS diets were fed to eight he althy subjects in three meals for 1 d. Breath hydrogen and two blood s amples were collected over a 28-h period. The high-RS diet provided 59 .1 +/- 4.7 g (<(chi)over bar> +/- SE) RS and the low-RS diet provided 5.2 +/- 0.4 g RS. Breath hydrogen and the average total serum acetate were significantly higher during the high-RS diet than during the low- RS diet: 34.1 +/- 4.7 and 23.9 +/- 3.9 ppm (P < 0.001) and 169.1 +/- 1 2.8 and 118 +/- 6.6 mu mol/L (P < 0.01), respectively. Butyrate and pr opionate were also detected in serum samples. Although not statistical ly significant, there was a trend (P = 0.087) for butyrate to increase with the high-RS diet. Subjects reported greater gastrointestinal sym ptoms during the high-RS diet. These results suggest that RS may have effects comparable with those of some fermentable dietary fibers.