Dja. Jenkins et al., PHYSIOLOGICAL-EFFECTS OF RESISTANT STARCHES ON FECAL BULK, SHORT-CHAIN FATTY-ACIDS, BLOOD-LIPIDS AND GLYCEMIC INDEX, Journal of the American College of Nutrition, 17(6), 1998, pp. 609-616
Objective: To assess the effects on fecal bulking, fecal short chain f
atty acid (SCFA) production, blood lipids and glycemic indices of two
different forms of resistant starch (RS2 and RS2) from a high-amylose
cornstarch. Methods: Twenty-four healthy subjects (12 men; 12 women) c
onsumed four supplements taken for 2 weeks in random order separated b
y 2-week washout periods. The supplements were a low-fiber (control) a
nd supplements providing an additional 30 g dietary fiber as wheat bra
n (high-fiber control) or the equivalent amount of resistant starch an
alyzed gravimetrically as dietary fiber from RS, or RS,. Four-day feca
l collections and 12-hour breath gas collections were obtained at the
end of each period. Fasting blood was taken at the beginning and end o
f each period. Glycemic indices of supplements were also assessed. Res
ults: The wheat bran supplement increased fecal bulk 96+/-14 g/day com
pared with the low-fiber control (p<0.001) with the mean for both resi
stant starches also being greater (22+/-8 g/day) than the low-fiber co
ntrol (p=0.013). On the resistant starch phases, the mean fecal butyra
te:SCFA ratio, which has been suggested to have positive implications
for colonic health, was significantly above the low-fiber control by 3
1+/-14% (p=0.035). Resistant starches did not alter serum lipids, urea
or breath H-2 or CH4. No significant differences in glycemic index we
re seen between the RS and control supplements. Conclusion: The potent
ial physiological benefits of the resistant starches studied appear to
relate to colonic health in terms of effects on fecal bulk and SCFA m
etabolism.