• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.5
• /
• pp.945-951
• /
• 1998

The purpose of this study was to investigate the effects of dietary xylooligosaccharide on lipid levels of serum in rats fed high cholesterol diet. Male Sprage-Dawley rats weiging 100$\pm$10g were randomly assigned to groups of two normal(N, N+10X) and four high cholesterol diets which contained 1%(w/w) cholesterol. High cholesterol diet groups were classified to xylooligosaccharide free diet (C group), 5% xylooligosaccharide diet(C+5X group), 10% xylooligosaccharide diet(C+10X group) and 15% xylooligosaccharide diet(C+15X group) according to the level of dietary xylooligosaccharide supplementation. These experimental diets were fed ad libidum for 4 weeks. The weight gain of high cholesterol diet group were significantly increased more than that of normal group, but those of 10% and 15% dietary xylooligosaccharide groups were significantly decreased more than that of high cholesterol diet(C)group. The higher content of xylooligosaccharide, the more food intake was increased. The food efficiencies of 10%, 15% cholesterol diet groups were lower than that of high cholesterol diet(C)group. The levels of serum triglyceride(TG) and total cholestoral were significantly high in cholesterol diet groups compared with normal diet group but were decreased in groups fed 5% and 10% dietary xylooligosaccharide. Especially, the lowest level showed in group fed high cholesterol diet containing 10% xylooligosacchride. High cholesterol diet group containing 10% xylooligosaccharide increased HDL-cholesterol level and then decreased LDL-cholesterol level and atherogenic index compared with other groups. The level of TBARS(thiobarbituric acid reactive substances) in serum was decreased in rat group fed xylooligosaccharide in high cholesterol diet. The higher content of xylooligosacchride, the more gastrointestinal transit time was decreased. The results indicate that dietary xylooligosaccharide can improve status of TG and total cholesterol and repress lipid peroxidation in serum lipid at hypercholesterolemia induced by high cholesterol diet.

• Journal of Life Science
• /
• v.18 no.1
• /
• pp.52-57
• /
• 2008

Xylan is a major hemicellulose component of the cell walls of monocots and hardwood, representing up to 30% of the dry weight of these plants. To efficiently hydrolyze xylan, the endoxylanase gene from Bacillus sp. was expressed in B. subtilis DB431 by introducing the plasmid pJHKJ4. The total activity of the recombinant endoxylanase reached about 857 unit/ml by batch fermentation of B. subtilis DB431/pJHKJ4 in LB maltose medium. The majority (>92%) of endoxylanase was efficiently secreted into the culture medium. The recombinant endoxylanase hydrolyzed more the birchwood xylan efficiently than the other xylans. When 4 % concentration of xylan was used, the highest production of xylooligosaccharide was observed, and xylobiose and xylotriose were the major products. Optimal amount of enzyme and reaction time for producing xylooligosaccharide were found to be 10 unit and 1 hr, respectively. In addition, the temperature of $40^{\circ}C{\sim}50^{\circ}C$ gave the highest production of xylooligosaccharide. Consequently, the optimized conditions for the production of xylooligosaccharide through the hydrolysis of xylan were determined as follows: 10 unit endoxylanase, $50^{\circ}C$, 4% birchwood xylan, 1 hr reaction.

• Journal of Nutrition and Health
• /
• v.40 no.2
• /
• pp.154-161
• /
• 2007

This study investigated the effects of xylooligosaccharide on feces bifidobacteria proliferation, lactic acid concentration and lipid metabolism in healthy woman. Fourteen volunteers were randomly assigned to 2 groups : 1.4 g/day xylooligosaccharide intake group, 2.8 g/day xylooligosaccharide intake group. The duration of the study was 28 days. The amount of feces and excretion time were not affected by xylooligosaccharide intake. The color of feces changed to yellow brown, and hardness of stool and effort to evacuation were reduced by xylooligosaccharide intake. Xylooligosaccharide intake reduced the fecal pH significantly after 14 days in 2.8 g/day intake group (p < 0.05). The number of fecal bifidobacteria were significantly increased after 28 days in 1.4 g/day intake group (p < 0.05), and in 2.8 g/day intake group, the number of fecal bifidobacteria significantly increased after 14 days (p < 0.05). Water contents of feces were not affected by xyloolgosacchride intake. The fecal triglyceride and cholesterol concentrations were increased in 2.8 g/day intake group (p < 0.05), and in 1.4 g/day intake group, fecal cholesterol concentration only was increased (p < 0.05). The fecal lactic acid concentration was significantly increased in 2.8 g/day intake group (p < 0.05). Serum trigly-ceride, cholesterol and glucose concentration were significantly decreased in 2.8 g/day intake group (p < 0.05). In conclusion, xylooligosaccharide dietary supplementation may be beneficial to gastrointestinal health and lipid metabolism, and 2.8 g/day intake was more effective than 1.4 g/day intake.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.6
• /
• pp.1197-1203
• /
• 2001

This study was conducted to examine the effects of dietary xylooligosaccharide on UDP-glucuronyl transferase (UDP-GTase) activity and excretion of fecal sterols in rat fed high cholesterol diet. Sprague-Dawley male rats weighing 100$\pm$10 g were randomly divided into five groups, one with normal diet and four with high cholesterol diets containing 1% cholesterol (w/w). The high groups with cholesterol diet groups were classified into xylooligosaccharide free diet (C), 5% xylooligosaccharide diet (C5XO), 10% xylooligosaccharide diet (C10XO), and 15% xylooligosaccharide diet (C15XO) group according to the five groups of dietary xylooligosaccharide by weights. The experimental diets were fed ad libidum for 4 weeks. Fecal weights were increased 86% by xylooligosaccharide. Fecal total lipid contents including fecal neutral and acidic sterols in xylooligosaccharide groups were significantly higher than those of the normal and C groups, and especially that of C10XO group was the highest among all experimental groups. Activity of UDP-glucuronyl transferase (UDP-GTase) in liver in C group was 35% higher than that of normal group and the activities in C5XO, C10XO and C15XO groups were 15%, 41%, and 21% higher than in C group, respectively. Fecal bile acid excretions per day were increased 3.1, 3.6 and, 2.8 folds in C5XO, C10XO, and C15XO groups, respectively, compared with that of C group. Contents of neutral sterol, coprostanol, and coprostanone were higher in xylooligosaccharide groups than in C group. These results suggest that dietary xylooligosaccharide may act as potential substitute for a dietary fiber capable of improving a gastrointestinal function and lipid metabolism.

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.259-264
• /
• 1999

To evaluate the bacterial reverse mutation of xylooligosaccharide(XO)s the in vitro Ames test using Salmonella typhimurium (TA9S, TAIOO, TA1535, TA1537) and Escherichia coli (WP2 uvrA) was performed. XO was negative in Ames test with Salmonella typhimurium and Escherichia coli with and without rat liver microsomal enzyme (S-9 fraction). According to the results, XO does not cause bacterial reverse mutation.

• Journal of Food Hygiene and Safety
• /
• v.14 no.3
• /
• pp.255-258
• /
• 1999

The acute toxicity of xylooligosaccharide(XO) was evaluated in SD rats. Groups of 15 male and 15 female rats were orally administered XO (0, 5000 or 10000 mg/kg). The changes of body weight and clinical signs were investigated for 14 days after treatments. No death and toxic effects were observed for 14 days. Soft stool and diarrhea appeared right after treatment for over dose and non-digestive feature of XO but these clinical signs disappeared on the next day. No significant changes in body weight and abnormal gross findings were observed in relation to XO. According to the results, XO has no special toxic effects and LD50 values of XO are above 10000 mg/kg in male and female rats.

• Journal of Nutrition and Health
• /
• v.48 no.5
• /
• pp.398-406
• /
• 2015

Purpose: In the present study, we aimed to evaluate the effect of sucrose containing 2 different levels of xylooligosaccharide on the glycemic index (GI) and blood glucose response in healthy adults. Methods: Healthy adults (4 male participants and 6 female participants, n = 10) were randomized to receive glucose, sucrose, sucrose containing 7% xylooligosaccharide active elements (Xylo 7), or sucrose containing 10% xylooligosaccharide active elements (Xylo 10). Each participant was administrated one of these materials once a week for 8 weeks and an oral glucose tolerance test was performed. Results: We found a reduction in the glycemic response to sucrose that included xylooligosaccharide active elements (Xylo 7 and Xylo 10). The glycemic indices of sucrose, Xylo 7 and Xylo 10 were 68.9, 54.7, and 52.5, respectively. The GI values of Xylo 7 and Xylo 10 were similar to that of foods with low GI. The percentage reduction of GI value caused by sucrose containing xylooligosaccharide active elements was significantly different and dose-dependent as compared to that caused by sucrose alone (p < 0.05). The reduction in the glycemic response to Xylo 7 and Xylo 10 was 21% and 24%, respectively, as compared to the glycemic response to sucrose. The attenuation of the glycemic response to Xylo 10 tended to be higher than that for Xylo 7 when the percentage of body fat was increased. Conclusion: These results demonstrated that xylooligosaccharide active elements may be effective in protecting humans against overconsumption of sucrose.

• Journal of Nutrition and Health
• /
• v.48 no.1
• /
• pp.19-29
• /
• 2015

Purpose: To investigate the effects of the intake of xylooligosaccharide-sugar mixture (XOS) on defecation frequency and symptoms in 56 young women (mean age of 22.1 years old) with constipation. Methods: Two experiments were conducted. In experiment 1, a randomized double-blind study was performed to evaluate the effect of 6 weeks' intake of 10 g sucrose containing 7% xylooligosaccharide or 10 g sucrose on constipation. In experiment 2, 24 g coffee mixture containing 12.8 g plant cream and 11.2 g xylooligosaccharide-sugar mixture was consumed by the subjects. During the study, the clinical efficacy was assessed by using a daily diary. The subjects indicated the number of frequencies they defecated in a day and the clinical symptom scores. Results: In experiment 1, the mean frequency of defecations was 2.07 in the pretreatment week and increased significantly to 4.05, 4.42, 4.84, 4.84, and 4.05 in weeks 2 to 6 of XOS intake, in comparison with the 3-3.67 with sucrose intake (sucrose, SUC). In experiment 2, the mean frequency of defecations significantly increased from 2.47 in the pretreatment week to 4.11-5.67 in weeks 1-6 of XOS intake. The occurrence of very loose or loose stools in the XOS group was significantly increased in weeks 5 and 6, compared with the pretreatment week and SUC group. XOS intake significantly alleviated the abdominal displeasure and feeling of residual stool leftness in weeks 2, 3, 5, and 6, while SUC did so in weeks 4 and 6 (p < 0.05). The coffee mixture containing xylooligosaccharide-sugar mixture reduced the abdominal displeasure and feeling of residual stool leftness from week 3 until the end of the experiment (p < 0.05). Conclusion: Our results suggest that xylooligosaccharide-sugar mixture intake was effective, without adverse effects, for the alleviation of constipation in the young women in this study.

• Journal of Food Hygiene and Safety
• /
• v.15 no.2
• /
• pp.151-166
• /
• 2000

The subacute toxicity of xylooligosaccharide (XO) was evaluated in SD rats. Groups of 60 male and 60 female rats were orally administered with 0, 333, 1000 or 3000 mg/kg of XO for 13 weeks. The changes of body weight, food and water consumption were investigated for 17 weeks, while heamatological values and histopathological findings were investigated at the end of the 13 weeks and 17 weeks including 4 weeks of recovery periods. No death and toxic effects were observed during the test periods. There were statistically significant changes in several parameters, but these change had no direct relationship to dosage. Clinical changes were general occurrence and no specific toxicity was related to XO. Gross necropsy and histopathology revealed that no target organs were found in the treated mouse with XO. According to the results, no-observed effect level of XO is estimated to be above 3000 mg/kg.

• Journal of Nutrition and Health
• /
• v.35 no.10
• /
• pp.1015-1022
• /
• 2002

This study was conducted to examine the effects of dietary xylooligosaccharides on hepatic HMG-CoA reductase activity and morphological exchange of liver in rats fed high fat diet. Sprague-Dawley male rats weighing 100 $\pm$ 10 g were randomly divided into four groups, two normal diets and two high fat diets containing 1% cholesterol and 10% lard. Two normal diets were classified into a basal diet (normal group) and 10% xylooligosaccharide diet (NX group). The high fat diet groups were classified into a HF group without xylooligosaccharides diet and HFX group supplemented 10% xylooligosacchride diet. Experimental diets were fed ad libidum to the rats for 4 weeks and then they were sacrificed. The body weight of high fat diet (HF group) was increased more than that of normal group, but it was significantly decreased by xylooligosacchrides supplementation. The food intake was not significantly different among the all groups. The weight of liver, small intestine and cecum of all xylooligosaccharide supplemented groups were significantly heavier than those of normal and HF groups. The activity of hepatic HMG-CoA reductase, a rate limiting enzyme of cholesterol biosynthesis, in xylooligosaccharide supplemented groups was higher than that of HF group. Light micrographs revealed that the structures of hepatocytes in xylooligosaccharide supplemented groups were preserved well, compared to HF group. The xylooligosaccharide supplementation exerted a lipid-lowering action by decreasing cholesterol and triglycerides contents in hepatic tissue. In conclusion, the activity of hepatic HMG-CoA reductase and damage of liver in rats fed high fat diets were improved by dietary xylooligosaccharides.