| J Nutr 1990 Sep;120(9):1046-53
Comparison between physiological
effects of konjac-glucomannan and propionate in baboons fed
Venter CS, Vorster HH, Van der Nest DG.
Department of Dietetics, Potchefstroom University for Christian
Higher Education, South Africa.
Dietary fiber and resistant starch are fermented by colonic
bacteria to short-chain fatty acids (SCFA) such as acetic, butyric
and propionic acid, which the colon absorbs. It has been suggested
that the beneficial metabolic effects of dietary fiber may be
mediated through propionate. We therefore compared the effects
of a soluble dietary fiber concentrate, konjac-glucomannan (K-GM),
and of propionate on plasma fibrinogen, serum and liver lipid,
glucose tolerance, insulin response and liver glycogen in baboons.
Twelve male baboons were fed a "Western" diet with or without
K-GM (5%) or sodium propionate (2%) supplements for periods
of 9 wk in a crossover, randomized order, with stabilization
periods in between. Measurements were taken at baseline and
after 4 and 9 wk of each study period. After 9 wk, total serum
cholesterol levels were significantly higher than pretest values
when baboons consumed the unsupplemented Western diet (25%,
p less than 0.05) or the propionate diet (17%, p less than 0.05).
Konjac-glucomannan prevented this increase. The high density
lipoprotein cholesterol concentration increased with all experimental
diets (p less than 0.05). The percentage of total cholesterol
as high density lipoprotein cholesterol, was significantly higher
with K-GM supplementation than with the other diets. Konjac-glucomannan
supplementation also resulted in lower than baseline values
for triglycerides (p less than 0.01) and circulating free fatty
acids (p less than 0.05) after 9 wk. Only the propionate diet
raised serum triglycerides significantly (by 6%) above baseline.
Liver cholesterol concentration was 31-34% lower, and the area
under the glucose tolerance curve was smaller with K-GM and
propionate diets (p less than 0.05) than with the unsupplemented
diet.(ABSTRACT TRUNCATED AT 250 WORDS)