D-Xylose as a sugar complement regulates blood glucose levels by suppressing phosphoenolpyruvate carboxylase (PEPCK) in streptozotocin-nicotinamide-induced diabetic rats and by enhancing glucose uptake in vitro

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. D-Xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of D-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with D-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with D-xylose. These groups were maintained for two weeks. The effects of D-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic beta-cells were analyzed. RESULTS: In vivo, D-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. D-Xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of D-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with D-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, D-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, D-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by beta-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.

Effect of xylooligosaccharide-sugar mixture on defecation frequency and symptoms in young women with constipation: a randomized, double-blind, placebo-controlled trial / 한국영양학회지

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.

Effect of different levels of xylooligosaccharide in sugar on glycemic index and blood glucose response in healthy adults / 한국영양학회지

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.

Effects of xylooligosaccharide-sugar mixture on glycemic index (GI) and blood glucose response in healthy adults / 한국영양학회지

PURPOSE: The objective of this study was to investigate the effects of xyloologosaccharide (XOS)-sugar mixture on glycemic index (GI) and blood glucose in human subjects. METHODS: Randomized double-blind cross-over studies were conducted to examine the effect of sucrose with 14% xyloologosaccharide powder (Xylo 14) and sucrose with 20% xylooligosaccharide powder (Xylo 20) on GI and postprandial glucose response at 15, 30, 45, 60, 90, and 120 min. RESULTS: GIs of Xylo 14 and Xylo 20 were 60.0 +/- 23.5 classified within medium GI range, and 54.3 +/- 17.7 within low GI range, respectively. Xylo 14 and Xylo 20 showed significantly lower area under the glucose curve (AUC) for 0-15 min (p = 0.0113), 0-30 min (p = 0.0004), 0-45 min (p < 0.0001), 0-60 min (p < 0.0001), 0-90 min (p < 0.0001), and 0-120 min (p = 0.0001). In particular, compared with glucose, the blood glucose levels of Xylo 14 and Xylo 20 were significantly lower at every time point between 15 and 120 min. CONCLUSION: The results of this study suggested that Xylo 14 and Xylo 20 had an acute suppressive effect on GI and the postprandial glucose surge.

Effects of short-term supplementation of erythritol-salt on urinary electrolyte excretion in rats / 한국영양학회지

PURPOSE: This study was conducted in order to investigate the diuretic effects of Erythritol (ET) salt on urinary electrolyte excretion in Sprague-Dawley Rats. METHODS: Animals were divided into two groups: Salt group (n = 7) and Salt + ET fed group (n = 7). Animals were provided food and water ad libitum. Supplements were administered orally to animals for one week. RESULTS: Body weights were not statistically different between groups either on Day 1 or Day 7. However, water consumption of the Salt + ET group was significantly higher than that of the Salt group on Day 1 and Day 7. Urine volume of the Salt + ET group was approximately 27% and 38% higher than that of the Salt group on Day 1 and Day 7. In addition, we found that the total amounts of urinary electrolytes, such as sodium and potassium, of the Salt + ET group were significantly higher than those of the Salt group on Day 7. We also found that serum electrolyte concentrations did not differ between two groups. These results demonstrated that salt intake with ET was effective in increasing urinary electrolyte excretion, which might be caused by higher water intake and diuretic effect inhibiting reabsorption of water, sodium, and potassium in renal tubules. CONCLUSION: The results suggest that short-term supplementation of ET salt can be a potential diuretic agent by inhibiting sodium and potassium reabsorption and inducing loss of water.