Chitosan And Fat Absorption
Kanauchi O; Deuchi K; Imasato Y; Shizukuishi M; Kobayashi E Applied Bioresearch Center, Kirin Brewery Co. Ltd., Gunma, Japan.
Biosci Biotechnol Biochem (JAPAN) May 1995, 59 (5) p786-90
Biomaterials (1997 Apr) 18(8):591-5
We investigated the mechanism for the inhibition of fat digestion by chitosan, and the synergistic effect of ascorbate. The important inhibition characteristics of fat digestion by chitosan from observations of the ileal contents were that it dissolved in the stomach and then changed to a gelled form, entrapping fat in the intestine. The synergistic effect of ascorbate (AsA) on the inhibition of fat digestion by chitosan is thought not to be acid-dependent but due to the specificity of AsA itself, according to the data resulting from using preparations supplemented with sodium ascorbate (AsN). The mechanism for the synergistic effect is considered to be 1) viscosity reduction in the stomach, which implies that chitosan mixed with a lipid is better than chitosan alone, 2) an increase in the oil-holding capacity of the chitosan gel, and 3) the chitosan-fat gel being more flexible and less likely to leak entrapped fat in the intestinal tract.
Chitin, Chitosan Impact on Nutrient Digestibility
Razdan A; Pettersson D Department of Food Science, Swedish University of Agricultural Sciences, Uppsala.
Br J Nutr (ENGLAND) Aug 1994, 72 (2) p277-88
Broiler chickens were fed on a control diet based on maize and maize starch or diets containing chitin, or 94, 82 or 76% deacetylated chitin (chitosans) with different viscosities (360, 590 and 620 m Pa.s respectively) at an inclusion level of 30 g/kg. Animals had free access to feed and water for the whole experimental period. On days 10 and 18 of the experiment chickens given the control and chitin-containing diets weighed more, had consumed more feed and had lower feed conversion ratios (g feed/g weight gain) than chitosan-fed birds. Feeding of chitosan-containing diets generally reduced total plasma cholesterol and high-density-lipoprotein (HDL)-cholesterol concentrations and gave an increased HDL:total cholesterol ratio in comparison with chickens given the control and chitin-containing diets. However, no significant reductions in plasma triacylglycerol concentrations resulting from feeding of the chitosan-containing diets were observed. The reduction in total cholesterol concentration and increased HDL:total cholesterol ratio were probably caused by enhanced reverse cholesterol transport in response to intestinal losses of dietary fats. The suggestion that dietary fat absorption was impeded by the chitosans was strengthened by the observation that ileal fat digestibility was reduced by 26% in comparison with control and chitin-fed animals. In a plasma triacylglycerol response study on day 21, feeding of 94 and 76%-chitosan-containing diets generally reduced postprandial triacylglycerol concentrations compared with chickens given the chitin-containing diet. Duodenal digestibilities of nutrients amongst chickens given the chitin-containing diet were generally lower than those of control and chitosan-fed birds indicating decreased intestinal transit time. The reduced caecal short-chain fatty acid concentrations of chickens given chitosan diets compared with the control diet illustrates the antimicrobial nature of chitosan. The fact that the three chitosan-containing diets affected the registered variables similarly indicated that the level of inclusion of chitosans in the diet exceeded the level at which the effect of the different viscosities could be significant.
Chitin, Chitosan and Weight
Tanaka Y Tanioka S Tanaka M Tanigawa T Kitamura Y Minami S, Okamoto Y Miyashita M Nanno M
Biomaterials (1997 Apr) 18(8):591-5
Chitin and chitosan were administered orally and parenterally into mice and their toxicity was investigated. When 5 mg of chitin were injected intraperitoneally every 2 weeks over a 12-week period, the mice were apparently normal, but histologically, many macrophages with hyperplasia were observed in the mesenterium and foreign-body giant-cell-type polykaryocytes were observed in the spleen. The polykaryocytes were also observed in the spleen of the mice injected subcutaneously with 5 mg of chitin, but no other changes were observed. When 5 mg of chitosan were injected intraperitoneally, the body weights of the mice decreased significantly and inactivity was observed in the fifth week. Histologically, many macrophages with hyperplasia were observed in the mesenterium. Subcutaneous injection of 5 mg of chitosan did not evoke the general and cellular abnormalities. Oral administration of 5% chitosan via a casein diet caused mouse body weights to decrease and also decreased the number of Bifidobacterium and Lactobacillus in normal flora of the intestinal tract. These results indicate that special care should be taken in the clinical use of chitin and chitosan over a long time period.
