The present study is the first to report the hypocholesterolemic effect of chitosan on humans. When 3-6 g/day of chitosan was given in the diet to 8 healthy males, total serum cholesterol significantly decreased, and when the ingestion was stopped, the value increased to the level before ingestion. Serum HDL-cholesterol was increased significantly by the ingestion of chitosan. The excreted amounts of primary bile acids, cholic acid and chenodeoxycholic acid, into the feces was significantly increased by the ingestion of chitosan, and the amount of cholic acid excretion decreased significantly after the ingestion was stopped. These facts suggest that chitosan combined bile acids in the digestive tract, and that the combined product was excreted into the feces. This, in turn, deceased the resorption of bile acids, so that the cholesterol poool in the body was decreased and the level of serum chrolesterol consequently decreased.Chitin is a polysaccharide contained in the cuticle of Crustacea and insects, and in the cell walls of some kinds of mold. Chitosan is the general name for the dilute acid-soluble group of deacetylated chitin. The chemical structure of chitosan is similar to that of cellulose in dietary fiber. Chitosan is not hydrolyzable by the digestive enzymes in humans, so it can be classed as one of the dietary fibers of animal origin. However, it is a cationic polymer having an amino group in its chemical structure, which is a characteristic greatly different from those of other dietary fibers.Many functions of chitosan attributable to its amino group are known. Among them, the most noticeable is its hypocholesterolemic effect,l -6) and several studies on its mechanism have been reported. 5, 7) According to these reports, it has been said that chitosan is .dissolved in the digestive tract under acidic conditions, combines bile acid with its ion-exchanging function, and excretes the combined bile acid outside the body; consequently, it decreases the cholesterol pool in the body. However, all of these studies on the hypocholesterolemic effect of chitosan so far reported have used animals,1-6) and there is no report on a study of the effects on humans. Moreover, data for elucidating the mechanism were obtained mostly by in vitro studies,7) and the proposed mechanism based upon animal studies is not entirely clear.The present study is the first to report the hypocholesterolemic effect of chitosan on humans. The results obtained are particularly useful for the effect of chitosan on the metabolism of serum cholesterol and its possible mechanism of action.. Materials and MethodsTest subjects. This study was performed in conformity with the spirit of the "Declaration of Helsinki". The test subjects were 8 healthy male volunteers between 20 and 23 years of age, who were informed of the details of the aims, contents and methods of the study, and after giving their consent, decided to participate in the study of their own free will. All of them were university studuents, and Table I shows the background factors f...

Isomaltooligosaccharides (IMO), sweeteners derived from corn-starch, selectively promote the growth of bifidobacteria in the human intestine. The metabolic fate of IMO in healthy men was investigated. The expiration rates of excess (13)CO2 and hydrogen of six men were measured while sedentary and while taking physical exercise after the (13)C-labeled IMO intakes. The breath H2 excretion kept at a constant state after IMO ingestion in the sedentary test and increased in the exercise test. The serum glucose and serum insulin increased 30 min after IMO ingestion. The (13)CO2 recoveries were 28.7% in the sedentary test and 60.9% in the exercise test. These recoveries were 70-80% compared those of maltose. These results indicated that a part of IMO was digested and the residual IMO was fermented by intestinal flora. The energy value of IMO might be about 75% of that of maltose.

The effect of koji prepared with Aspergillus oryzae and beni-koji prepared with Monascus iilosus on blood pressure of spontaneously hypertensive rats (SHR) was studied. Male adult SHR -were fed semi-purified chow containing 1% NaCl with 5-10% koji or 3-10% beni-koji for 3 weeks. The blood pressure of the animals fed one of the kojis was 7'-15% lower than that of the control group. Beni-koji had a stronger hypotensive effect than koji. Koji and beni-koji did not affect blood glucose, plasma cholesterol, plasma triglycerides, or mineral metabolism. These results suggested that koji and beni-koji suppress rises in blood pressure. The mechanism of the effect did not involve Na/K ion-exchange in the gastrointestinal tract, which would inhibit Na absorption.

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